a r X i v :a s t r o -p h /0503352v 2 24 M a r 2005
Astronomy &Astrophysics manuscript no.INT˙?n February 2,2008
(DOI:will be inserted by hand later)
INTEGRAL observations of SS433:Results of a coordinated
campaign
A.M.Cherepashchuk 1,R.A.Sunyaev 2,3,S.N.Fabrika 4,K.A.Postnov 1,10,S.V.Molkov 2,E.A.Barsukova 4,E.A.Antokhina 1,T.R.Irsmambetova 1,I.E.Panchenko 1,E.V.Sei?na 1,N.I.Shakura 1,A.N.Timokhin 1,I.F.Bikmaev 5,N.A.Sakhibullin 5,Z.Aslan 6,7,I.Khamitov 6,A.G.Pramsky 4,O.Sholukhova 4,Yu.N.
Gnedin 8,A.A.Arkharov 8,https://www.doczj.com/doc/855990208.html,rionov 9
1Sternberg Astronomical Institute,Universitetsky pr.13,119992,Moscow,Russia
2Space Research Institute,Russian Academy of Sciences,Profsoyuznaya 84/32,117810Moscow,Russia 3Max-Planck-Institute f¨u r Astrophysik,Karl-Schwarzschild-Str.1,D-85740Garching bei M¨u nchen,Germany,4Special Astrophysical Observatory,Nizhnij Arkhyz,Karachaevo-Cherkesiya,369167,Russia 5Kazan State University,Kremlevskaya str.18,420008,Kazan,Russia
6TUBITAK National Observatory,Akdeniz Universitesi Yerleskesi,07058Antalya,Turkey 7Akdeniz University,Physics Department,07058Antalya,Turkey 8Pulkovo Observatory,St.-Petersburg,Russia 9St.-Petersburg University,Russia 10
University of Oulu,Finland
Abstract.Results of simultaneous INTEGRAL and optical observations of the galactic microquasar SS433in May 2003and INTEGRAL /RXTE observations in March 2004are presented.Persistent precessional variability with a maximum to minimum uneclipsed hard X-ray ?ux ratio of ～4is discovered.The 18-60keV X-ray eclipse is found to be in phase with optical and near infrared eclipses.The orbital eclipse observed by INTEGRAL in May 2003is at least two times deeper and apparently wider than in the soft X-ray band.The broadband 2-100keV X-ray spectrum simultaneously detected by RXTE/INTEGRAL in March 2004can be explained by bremsstrahlung emission from optically thin thermal plasma with kT ～30keV.Optical spectroscopy with the 6-m SAO BTA telescope con?rmed the optical companion to be an A5-A7supergiant.For the ?rst time,spectorscopic indications of a strong heating e?ect in the optical star atmosphere are found.The measurements of absorption lines which are presumably formed on the non-illuminated side of the supergiant yield its radial velocity semi-amplitude K v =132±9km/s.The analysis of the observed hard X-ray light curve and the eclipse duration,combined with the spectroscopically determined optical star radial velocity corrected for the strong heating e?ect,allows us to model SS433as a massive X-ray binary.Assuming that the hard X-ray source in SS433is eclipsed by the donor star that exactly ?lls its Roche lobe,the masses of the optical and compact components in SS433are suggested to be M v ≈30M ⊙and M x ≈9M ⊙,respectively.This provides further evidence that SS433is a massive binary system with supercritical accretion onto a black hole.
Key words.stars:individual:SS433–stars:binaries:eclisping –X-rays:binaries
1.Introduction
SS433is a massive eclipsing X-ray binary system at an advanced evolutionary stage.It is recognized as a super-critically accreting microquasar with a precessing accre-tion disk and mildly relativistic (v ≈0.26c )jets.Since its discovery in 1978(Clark and Murdin 1978,Margon et al.1979),this unique X-ray binary has been deeply investigated in optical,radio,and X-rays (see reviews by Margon 1984,Cherepashchuk 1988,2002and Fabrika 2004for more detail and references).
2Cherepashchuk et al.:INTEGRAL observations of SS433
3)The accretion disk and relativistic jets regularly pre-
cess with a period of162.5days.Both the precession pe-
riod and the disk inclination angle to the orbital plane
(～20?)on average remain constant over tens of years.
4)The source exhibits orbital eclipsing periodicity
with period P orb=13d.082.The shape of the optical
light curve varies signi?cantly with precessional phase
(Goranskij et al.1998ab,Cherepashchuk and Yarikov
1991).The orbital period is found to be very stable over
more than25years,despite the high mass exchange rate between the binary components and strong wind mass loss (v≈2000km/s,˙M?10?4M⊙/yr)from the supercritical accretion disk.
The unsolved puzzles of SS433still remaining to be solved include:(1)the nature of the relativistic object,(2) the mechanism of collimation and acceleration of matter in jets to the relativistic velocity～80,000km/s,(3)the nature of the precessional phenomena in this X-ray binary system(Chakrabarti,2002).
The INTEGRAL observations of SS433in2003dis-covered a hard(up to100keV)X-ray spectrum in this supercritically accreting microquasar(Cherepashchuk et al.2003,2004),suggesting the presence of an extended hot(with a temperature up to108K)region in the cen-tral parts of the accretion disk.These new data made it possible to compare the eclipse characteristics of SS433at di?erent energies:soft X-rays(2-10keV,the ASCA data), soft and medium X-ray(1-27keV,the Ginga data),hard X-rays(20-70keV,the INTEGRAL data),and the opti-cal.This comparison allows us to investigate the inner-most structure of the supercritical accretion disk and to constrain the basic parameters of the binary system.
This paper is organized as follows:Section2lists the participants of the observational campaign.Section 3describes the X-ray spectra and light curves obtained. Section4presents the analysis of hard X-ray precessional and orbital variability of SS433.Section5reports the re-sults of optical and infrared photometry.Section6de-scribes in detail the simultaneous optical spectroscopy of SS433obtained with the6-m BTA telescope and the mea-surements of the optical radial velocity curve.The impli-cations of our observations for binary masses in SS433are summarized in Section7,and Sections8and9give the discussion and conclusions,respectively.
2.Observational campaign
The coordinated multiwavelength observational campaign of SS433was organized during the INTEGRAL observa-tions of the SS433?eld in March-June2003with the par-ticipation of the following research teams.
1.Special Astrophysical Observatory of the Russian Academy of Science(SAO RAS).High signal-to-noise op-tical spectroscopy of SS433at the6-m telescope.
2.Crimean Station of the Sternberg Astronomical Institute.BVR-photometry at the0.6-m
telescope.Fig.1.IBIS/ISGRI spectrum of SS433collected over INTEGRAL orbits67-69in May2003.The best?t(solid line)is for an exponential cut-o?with E c=14±2 keV.Reducedχ2=0.32for7degrees of freedom(dof), CL≈95%.
3.Kazan State University.Optical photometry at the Russian-Turkish 1.5-m telescope RTT-150at the TUBITAK National Observatory(Turkey).
4.Infrared K-photometry was performed with the1.1-m AZT-24telescope of the Pulkovo Observatory in Italy, Osservatorio di Campo Imperatore.
5.Radio monitoring at cm wavelength:the RATAN-600radio telescope of SAO RAS.The source was found to be in its non-?aring(quiet)state in May2003(Trushkin 2003).
SS433was within the?eld of view of the IBIS telescope during the INTEGRAL observations(March2004)of the Sagittarius arm tangent region centered on l=+40?,b= 0?.We included part of these observations in our analysis. In contrast to the observations in May2003,radio moni-toring showed that SS433had been in its?aring(active) state(Trushkin2004).
3.IBIS/ISGRI light curves and spectra
The INTEGRAL IBIS/ISGRI data were analyzed us-ing both publicly available ISDC software(OSA-3ver-sion)and the original software elaborated by the IKI INTEGRAL team(see Revnivtsev et al.2004b for more detail).The latter allows better sensitivity in constructing maps and spectra.The main results can be summarized as follows.
A.The IBIS/ISGRI spectrum of SS433(25-100keV) in May2003as processed by the OSA-3software can be ?tted by a power-law～E?αwith photon indexα≈2.7±0.13,taking into account the10%systematic errors.A satisfactory?t is also obtained using an exponential cut-o?exp(?E/E c)with E c～12?16keV(Fig.1).
The integrated hard X-ray luminosity in May2003was L x(18?60keV)～4×1035erg/s,L x(60?120keV)～
Cherepashchuk et al.:INTEGRAL observations of SS433
3
Fig.2.RXTE PCA and IBIS/ISGRI spectrum of SS433obtained during simultaneous RXTE/INTEGRAL ob-servations of SS433in March 24-27,2004.The best ?t (solid line)is for bremsstrahlung emission from optically thin plasma with kT =29.0±0.7keV (model ”bremss”from the XSPEC package).Reduced χ2=0.77for 50dof,CL ≈88%.
time (sec)
c o u n t s /s e c
Fig.3.IBIS/ISGRI 20-40keV (upper panel)and 40-70keV (bottom panel)count rates of SS433(without back-ground subtraction)obtained in May 2003.The time ori-gin is MJD=52763.95.The egress part of the X-ray eclipse was kindly provided by Dr.Diana Hannikainen.
Table 1.Best-?t parameters of the joint RXTE+INTEGRAL spectrum of SS433observed in March 24-27,2004.The model is bremsstrahlung emis-sion and a Gaussian emission line (from the XSPEC package).The energy of the emission line was a free pa-rameter.The physical nature of the line is not discussed in the present paper.
Parameter
kT Emission line
Line energy width (kev)
(keV)
(keV)
2×1035erg/s (assuming the 5kpc distance to SS433),which is about 10%of the soft X-ray jet luminosity.
Using the OSA-3software,we could not signi?cantly detect the source in the JEM-X data.Instead,we made use of the more detailed RXTE observations of SS433per-formed simultaneously with INTEGRAL in March 2004to obtain the broadband 2-100keV spectrum of SS433.The source was observed a few days after the disk maximum opening phase.The OSA-3software also did not allow us to signi?cantly detect the source at energies above 70keV,so we used the IKI software to obtain the SS433spectrum up to 100keV.This software has proven its quality and e?ciency in processing INTEGRAL observations of the Galactic center (Revnivtsev et al.2004b).
The resulting broadband X-ray spectrum of SS433in March 2004is shown in Fig.2.It can be adequately ?tted by the bremsstrahlung emission from optically thin ther-mal plasma with kT ～30keV (model ”bremss”from XSPEC package was used;see Table 1).The reduced chi-square value for 50dof is ～0.8,which corresponds to a null hypothesis probability of ～0.9.
B.The IBIS/ISGRI count rates of SS433in May 2003are presented in Fig.3.The X-ray eclipse at hard ener-gies is observed to be slightly narrower than the optical one,slightly broader than in the 4.6-27keV Ginga energy range and displays extended wings (Fig.6).This is oppo-site to what is found in ordinary eclipsing X-ray binaries (like Cen X-3,Vela X-1etc.),in which the X-ray eclipse duration decreases with energy.
C.The eclipse depth is observed to be at least 80%in hard X-rays compared to ～50%in the 4.6-27keV band (Fig.4-6).
D.The 25-50keV X-ray ?ux increases from ～5to ～20mCrab during March-May 2003when the source precessed from the crossover (T2)phase to the maximum opening disk phase (T3).This modulation is ～2times larger than observed in the 2-10keV energy band (see Fig.5).Thus,both precessional and eclipsing hard X-ray variabilities in SS433exceed by ～2times those in the standard X-ray band (Fig.5).This suggests a more compact vertical structure of the hard X-ray emitting region in the central parts of the accretion disk.
4.Analysis of precessional and orbital variability of SS433in the 25-50keV energy range 4.1.Precession variability
As mentioned above,the 25-50keV ?ux of SS433varies from F min ～5mCrab to F max ～20mCrab,with F min and F max corresponding to precession phases of the disk seen edge-on (moment T2)and at maximum open (moment T3),respectively,yielding the ratio A pr ≡F max /F min ～ 4.In Fig.4we present all our available INTEGRAL observations of SS433.The left panel shows the 2003data (INTEGRAL orbits 49,51,53,56,58,60,67-70).The right panel shows the 2004data (March 24-25,orbits 176and 177).The uneclipsed ?ux of SS433in
4
Cherepashchuk et al.:INTEGRAL observations of SS433
527005272052740527600
510152025
30
5308553100
51015202530Fig.4.Precessional hard X-ray (25-50keV)variability of SS433.Left panel:March-May 2003.Right panel:March 2004.The ?lled squares mark the T3precession phase according to ephemeris by Goranskij et al.[1998ab].The upper axis shows
the precessional phase according to the same ephemeris.
102030405060
70
123456Fig.5.The precession and eclipse amplitudes of SS433at di?erent energies in the quiet state:A pr (squares and solid line)and A ecl (triangles and dashed line).
2004(when the source was observed near the T3phase)is comparable within the errors with the maximum ?ux observed near the T3phase in 2003(these phases are in-dicated by the ?lled squares).This suggests that the pre-cessional hard X-ray variability of SS433stays constant at least over several precessional cycles.
The amplitude of the precession variability in SS433in di?erent X-ray bands appears to be monotonically in-creasing with energy (Fig.5,the squares and the solid line;Table 2).For example,archive RXTE/ASM data collected over several years (only quiet states of SS433have been selected)indicate that A pr (1.5?5keV)=1.6,A pr (5?12keV)=2.4(Fabrika et al.2004).The errors are due to the SS433?ux at the crossover being heavily ab-sorbed (especially at the ?rst crossover).The Ginga data (Kawai et al.1989,Yuan et al.1995)also ?t this depen-dence (Table 2).The monotonic increase of the precession
Table 2.Change of the precession amplitude of SS433A pr with energy
Energy range
A pr
Data
Ref.
keV
[1]-Fabrika et al.2004;[2]-Kawai et al.1989;[3]-Yuan et al.1995;[4]-Cherepashchuk et al.2003
amplitude with energy is consistent with the model of an emitting region in SS433as a cooling out?ow.
For a jet of ?nite length or consisting of individ-ual evolving fragments with ?nite life times (Lind and Blandford 1985;Begelman et al.1984;Panferov and Fabrika 1997),the intensity of radiation in the jet rest frame is J co =(1+z )2+αJ obs ,where J obs is the observed intensity of the jet emission,z =?δν/νis negative for the approaching jet and αis the spectral index (I ν∝ν?α).With appropriate values of the spectral index,the preces-sion amplitude due to the relativistic beaming only in the case where both jets are always seen and are not screened by the accretion disk would be ～1.1,and in the case that the receding jet is fully screened by the disk it would be ～1.5.So the large (～4times)precession variability found in the hard X-ray band 25-50keV cannot be ex-plained only by the jet relativistic beaming and should be almost fully caused by geometric screening of the in-ner disk structure producing hard X-rays by the edge of the precessing thick accretion disk.The precession light curve in the 25-50keV energy band exhibits a signi?cant irregular variability which is apparently related to the non-stationarity of the outer edges of the geometrically thick accretion disk.
4.2.Hard X-ray eclipse
The INTEGRAL observations in May 9-11,2003,enable us to study in detail its hard X-ray eclipse.We have used our data of May 9and 11.Data for May 10,2003,were kindly provided by Dr.Diana Hannikainen.The main eclipse falls on the precession phase ψpr =0.09(according to the ephemeris by Goranskij et al.1998a),fairly close to the T3(disk maximum opening)phase.
The primary X-ray eclipse in the 18-60keV energy band (IBIS/ISGRI data)is plotted in Fig.6.The points are averaged over 5and 10INTEGRAL scienti?c windows (10000and 20000s,respectively).For comparison,we plot the 4.6-27keV X-ray eclipse observed by Ginga (Kawai et al.1989,Yuan et al.1995)at about the same precession phase.The upper panel in Fig.6also shows the optical
Cherepashchuk et al.:INTEGRAL observations of SS4335 Table3.Primary X-ray eclipse depth A ecl variations with
energy
Energy E A ecl Data Ref.
keV keV
[1]-Kawai et al.1989;[2]-Yuan et al.1995;[3]-Cherepashchuk et al.2003
(V)light curve observed simultaneously with INTEGRAL in Crimea and SAO(see below).The upper panel demon-strates the absence of any noticeable lag between optical and hard X-ray primary eclipses.
Fig.6shows that the INTEGRAL eclipse is up to two times deeper than that observed by Ginga in softer X-ray bands.The ascending branch of the hard18-60keV eclipse clearly shows some irregularities.These features are sim-ilar to those observed by Ginga in the softer4.6-27keV X-ray band.If this is indeed the case,we can take the up-per envelope of the ascending branch of the X-ray eclipse light curve as a representative shape of the eclipse by the optical star body.Note that the X-ray eclipse minimum observed by Ginga was consistent with the synchronously observed optical one(Aslanov et al.1993).This proves that there is no appreciable phase shift between the mid-dle of the INTEGRAL and Ginga X-ray eclipses shown in Fig.6.
The X-ray eclipse depth as a function of energy is shown in Fig.5by the dotted line.The eclipse depth A ecl was de?ned as the ratio of the mean uneclipsed?ux before the eclipse to the middle eclipse?ux at the T3precession phase of SS433in the quiet state.These data are col-lected in Table3.Note the tendency for A ecl to increase with energy,which may mean that the hotter parts of the X-ray emitting region located closer to its base are totally eclipsed by the optical star.
The dependence of the precession amplitude and X-ray eclipse depth on energy is the same,suggesting similar screening e?ciency of the X-ray emitting region by the ac-cretion disk edge and by the optical star.This means that the size of the accretion disk can be comparable with that of the optical star.Such a conclusion has been also in-ferred from optical photometry(Fabrika&Irsmambetova 2002;Fabrika2004).
4.3.The geometric model of the system
To interpret the X-ray light curve of SS433we used a ge-ometric model applied earlier to the analysis of the Ginga X-ray eclipse(Antokhina et al.1992).We consider a close binary system consisting of an opaque”normal”star lim-ited by the Roche equipotential surface and a relativistic object surrounded by an optically and geometrically thick
0.60.81 1.2
0.5
1
1.5
0.5
1.5
Fig.6.The primary X-ray eclipse of SS433in the18-60keV energy band.IBIS/ISGRI data(May2003). Upper panel:X-ray light curve averaged over20000s (10INTEGRAL science windows,SCW)superimposed on the simultaneously obtained V optical photometric light curve(Crimea,SAO).Bottom panel:the same hard X-ray eclipse light curve averaged over10000s(5SCW)super-imposed on the Ginga4.6-27keV eclipse(?lled circles; from Kawai et al.1989,Yuan et al.1995)taken at about the same precession phase.The INTEGRAL data is the same in both panels,but the averaging is di?erent.
Fig.7.Geometrical model of the accretion disk and its “corona”.
”accretion disk”.The”accretion disk”includes the disk itself and an extended photosphere formed by the out?ow-ing wind.The orbit is circular,the axial rotation of the normal star is synchronized with the orbital revolution.
The disk is inclined with respect to the orbital plane by an angleθ.The opaque disk body(see Fig.7)is described by the radius r d and the opening angleω.The central ob-ject is surrounded by a transparent homogeneously emit-ting spheroid with a visible radius r j and height b j,which could be interpreted as a“corona”or a“jet”(without any relativistic motion).
Here r j,b j and r d are dimensionless values expressed in units of the binary separation a.The radius of the normal (donor)star is determined by the relative Roche lobe size, i.e.by the mass ratio q=M x/M v(M x here denotes the mass of the relativistic object).
Only the“corona”is assumed to emit in the hard X-ray band,while the star and disk eclipse it during orbital
6Cherepashchuk et al.:INTEGRAL observations of SS433 and precessional motion.During precession the inclination
of the disk with respect to the observer changes,causing
di?erent conditions of“corona”visibility.Observations of
the precessional variability can thus be used to obtain a
“vertical”scan of the emitting structure,restricting the parameters b j andω.The orbital(eclipse)variability ob-servations scan the the emitting structure“horizontally”, restricting possible values of r d,ω,q and r j.The joint analysis of precessional and eclipse variability enables us to reconstruct the spatial structure of the region in the accretion disk center where the hard X-rays are produced.
The position of the components of the system relative to the observer is determined by the binary orbit incli-nation angle i=78.8?,the disk inclination angle to the orbital planeθ=20.3?,the precession phaseψpr with ψpr=0at the maximum disk opening of SS433(T3,max-imum separation between the moving emission lines)and ψpr=0.34,0.66when the disk is seen edge-on(at the moving emission line crossover moments T1and T2,re-spectively).
To analyze the X-ray eclipse and precession light curve observed by INTEGRAL we have used the following three model shapes of the hard X-ray emitting region which can be parametrized by two parameters r j and b j:long narrow jets(r j?b j～a),short narrow jets(r j?b j?a),and short thick“jets”,or corona(r j>b j).For all models the formalχ2minimum is reached for a maximum allowed ac-cretion disk radius r d and the disk opening angleω～90?(see discussion below).The accretion disk radius was lim-ited by the distance from the relativistic object center to the inner Lagrangian point,which exceeds the radius of the Roche lobe around the compact star.This is natu-ral for a supercritical accretion disk with a strong radial out?ow(Zwitter,Calvani&D’Odorico,1991).Further ex-tension of the accretion disk is not justi?ed because of the presence of narrow absorption lines of the optical A5-A7 component in the spectrum,which means that there is no appreciable screening of the optical star by the disk.Such an extension of the disk would mean that the binary sys-tem is on the common envelope evolutionary stage,and so the narrow absorption lines from the optical star surface could not be observed.The orbital period stability over30 years of observations also suggests against the presence of a common envelope in SS433.
The results of our analysis can be summarized as fol-lows.
1.Long narrow jets(r j?b j～a)out?owing from the central object can be only partially screened by the disk during its eclipse and precession.Neither the observed eclipse depth nor the precession amplitude A pr～4can be explained by this model.(See Fig.
8).
2.Short narrow jets(r j?b j?a)where b j is found from the condition that the precession variability ampli-tude is A pr=4.The theoretical eclipse light curves for this model for di?erent mass ratios q are displayed in Fig.
9.For any q this model is inconsistent with the observed 18-60keV X-ray eclipse shape.Fig.8.X-ray eclipse?t with a model of narrow long X-ray emitting jets.Precession variability cannot be repro-duced by this model although the eclipse shape is?tted. The point at the center of the eclipse was taken from the Galactic Plane Survey scan in the beginning of the70th INTEGRAL orbit
Fig.9.The same as in Fig.8but for a model of nar-row short X-ray emitting jets for di?erent values of q. Precession variability amplitude A pr=4is reproduced, but the eclipse shape is not.
3.An extended corona(r j>b j)gives the best?t for the observed hard X-ray precession amplitude(A pr～4)and the observed eclipse shape(Fig.10).Minimum residuals in this model are attained for the mass ratio q= m x/m v≈0.2(Fig.11),which is close to that derived from ?tting the Ginga and ASCA observations with a narrow jet model(Kawai et al.1989,Kotani et al.1996).If we take into account only the upper envelope of the ascending X-ray eclipse branch(see above),the?t with q≈0.3seems to be acceptable as well(Fig.10and11).
The parameters b j andωappear to be related and cannot be determined separately.Formalχ2decreases as ω→90?,without any essential change of q forω>～80?. Obviously,the solution withω=90?(planar disk with zero thickness)could not provide any precessional vari-ability,so we acceptedω～80?.This also agrees with the estimates of the thickness of accretion disk from the rapid optical and X-ray variability corellation(Revnivtsev et al., 2004a).
From this analysis we conclude that in the framework of our geometrical model of the hard X-ray emitting re-
Cherepashchuk et al.:INTEGRAL observations of SS433
7 Fig.10.The same as in Fig.
8but with a model of an
extended oblate X-ray emitting region(“corona”)for dif-
ferent q.The precession variability amplitude is A pr=4.
r
j
Fig.11.χ2map(26dof)in the plane(r j,q)for models
with an extended oblate X-ray emitting region.The outer
edge of the accretion disk limited by the distance to the
inner Lagrangian point is shown by the solid line.The
precession variability amplitude is A pr=4.
gion in SS433,the observed precession amplitude and X-
ray eclipse shape are best reproduced by a broad oblate
corona above an optically thick accretion disk.The best
?t parameters are r j～0.3,b j～0.1andω～80?,the
mass ratio q=0.2?0.3.
Physically,such a corona could be thought of as hot
rare?ed plasma?lling the funnel around the jets.In this
picture outer parts of long thin jets that are not screened
by the funnel walls are responsible for emission in soft X-
rays,while the more extended hot corona inside the funnel
13.6
13.8
14
14.2
14.4
14.6
14.8
15
15.2
58 60 62 64 66 68 70 72 74
V
m
a
g
n
i
t
u
d
e
Time, JD-2452700
Comparison stars
N3
N4
Fig.12.V-light curve of SS433obtained at the RTT150
telescope(TUBITAK National Observatory,Turkey)si-
multaneously with INTEGRAL observations.Bottom:
photometry of control stars(V N3=12.93,V N4=12.70).
13.95
14
14.05
14.1
14.15
14.2
-0.5 0 0.5 1 1.5 2 2.5
V
m
a
g
n
i
t
u
d
e
UT, hours
Comparison stars
N3, V=12.93
N4, V=12.7
Fig.13.Rapid photometric variability of SS433during
the night05/06May2003
produces hard X-ray?ux.The estimation of the funnel size
～1012cm was obtained by Revnivtsev et al.(2004a)from
the analysis of rapid non-coherent variability in SS433.
The opening angle of the funnel can be quite large,so
the apparent size of the outer funnel that we model here
as an extended oblate corona over an opaque disk can be
comparable with the accretion disk size,as our best?t
parameters suggest.The nature of such a plasma inside
the funnel and how it maintains its stationarity requires
further studies.We also note that actual detection accu-
racy of the hard part of the broadband X-ray spectrum
of SS433obtained by INTEGRAL(Fig.2)is insu?cient
to de?nitely rule out the presence of the two-component
structure of the X-ray emitting region inferred from our
analysis.
8Cherepashchuk et al.:INTEGRAL observations of SS433
Fig.14.JHK-photometrical light curve of SS433ob-tained by AZT-24 1.1-m IR telescope in July-August 2003(Campo Imperatore,Italy).The dashed vertical lines mark the primary eclipse of SS433according to the ephemeris by Goranskii et al.(1998a).
5.Optical and IR photometry
5.1.Optical photometry
Photometry of SS433was performed simultaneously with INTEGRAL observations by the Russian-Turkish RTT-150telescope of Kazan University at the TUBITAK National Observatory,Turkey.Observations were made using commercial camera(model DW436,https://www.doczj.com/doc/855990208.html,)which is termoelectrically cooled to?60?C. The CCD was provided for RTT150by Max-Planck Institute for Astrophysics(Garching,Germany).It is a low noise back-illuminated model from EEV with2048x 2048pixels of13.5μsize.The full?eld of view is8x8 arcmin with a frame reading time of40sec at2x2bin-ning.To increase the time resolution only parts of the?eld of view with reference stars N1,2,3,4,5(Leibowits and Mendelson,1982)around SS433were captured.The ob-tained V-light curve is presented in Fig.12.Strong(～0.15 mag)intranight variability of the source on timescales ～100s-100min is clearly detected(see Fig.13for the night05/06May2003).
The mean V light curve during the eclipse obtained at the Crimean Laboratory of SAI(Nauchnyi,Crimea)si-multaneously with the INTEGRAL observations is shown in the upper panel of Fig.6.The detector was a pulse-counting,single-channel broad-band WBVR photoelec-tric photometer installed on a Zeiss-600re?ector.The photometer and software were designed and manufac-tured by I.I.Antokhin and V.G.Kornilov(SAI).The data were collected in the standard way using di?erential tech-niques.The main comparison star was C1with magnitude V=11.51(Gladyshev et al.1980).The typical rms mea-surement errors in V were0.02-0.03.The mean V light curve during the INTEGRAL observations corresponds to a quiet state of SS433.The optical eclipse minimum is ob-served at JD=2452770.863,as predicted by the orbital ephemeris given by Goranskij et al.(1998ab).
5.2.IR-photometry
Near IR observations of SS433were obtained at AZT-24 1.1m telescope in Campo Imperatore(Italy)during the period of July-August2003.Some observational data were obtained also in October-November2003.The AZT-24 telescope at the Campo Imperatore Observatory located 2150m above sea level(a cooperation between Rome, Teramo and Pulkovo Observatories)is used for photo-metric studies of variable sources at near infrared(NIR) wavelengths.The telescope is equipped with a SWIRCAM NIR256x256pixels imaging camera mounted at the focal plane of AZT-24.This camera was built at the Infrared Laboratories in Tucson(Arizona,USA).The SWIRCAM is equipped with a PICNIC array,an upgrade of the NIGMOS detector,with a working range of0.9-2.5μ. It yelds a scale of1.04arcsec per pixel resulting in a ?eld of view of4x4sq.arcmin.The observations were per-formed through standard Johnson JHK broadband?lters. The NIR monitoring of SS433started several orbits after the INTEGRAL observations.The JHK light curves are presented in Fig.14.The observations were done close to the crossover precession phase,where the orbital modu-lation appears to be signi?cantly reduced.Coincidence of the minima in the IR and optical light curves support our general geometrical model.
6.Optical spectroscopy
6.1.Spectral observations
The optical spectroscopy of SS433was performed at the 6-m telescope of the Special Astrophysical Observatory during6nights on April28and May9-132003simulta-neously with the INTEGRAL observations at the preces-sional phase corresponding to the maximum disk open-ing angle(T3).The Long-Slit spectrograph(Afanasiev et al.1995)at the telescope prime focus equipped with a 1000x1000Photometrics CCD-detector was used to obtain spectra with a resolution of3A(1.2A/pix).Standard techniques were used for spectral reduction and calibra-tion.
Table4lists the spectral observations and includes date,JD of the middle of observation,orbital and preces-sional phases,number of spectra during the night and the
Cherepashchuk et al.:INTEGRAL observations of SS4339
mean exposure,and spectral range used.We have taken spectra in the blue region as they are the most informa-tive when searching for the donor star absorption lines (Gies et al.,2002)and include the He IIλ4686emission line.On two nights,we obtained spectra in the red region to determine the orientation of relativistic jets and iden-tify the moving lines in all our spectra.The blue spectral range was shifted redward in the May2003observations because of the rising Moon.The signal-to-noise ratio in our spectra averaged over one night atλ=4250?A is≈60per resolution element in May10-13and it is≈80on other dates.The signal-to-noise ratio increases towards longer wavelengths.
6.2.Search for optical star lines
The strongest lines in SS433,hydrogen,HeI,HeII and some FeII lines,appear in emission.Emission line widths in SS433have FWHM～1000km/s,corresponding to ～10?A in the blue region.The emission lines are formed in the accretion disk wind and in gas streams in the binary system.A detailed description of the SS433spectrum can be found in Fabrika(2004).In precession phases close to the crossovers(T2),hydrogen(Hβand upper lines),HeI and FeII lines have narrow blueshifted absorption compo-nents with P Cyg or shell-like pro?les,which are formed in gas out?ow from the accretion disk.Weaker FeII lines ap-pear as pure absorptions in these precession phases.The absorption components are also strengthened in orbital phaseφ≈0.1;they are probably formed in the disk wind interacting with the star(Fabrika et al.1997).
The absorption components of the shell-like line pro-?les and even the pure absorption lines are likely be formed in the disk wind too,which follows from the strong dependence of their intensities(Crampton&Hutchins, 1981)and radial velocities(Fabrika et al.1997)on the pre-cession phase.Therefore,a search for the donor star spec-trum in SS433should be made with a certain caution.The search should be made among the weakest(photospheric) lines and in precession phases where the extended disk and its out?owing wind do not intersect the line of sight.In addition,stellar lines should be stronger in the middle of the accretion disk eclipse and weaker outside the eclipse (Gies et al.2002).The main criterion that the absorption lines are formed in the stellar photosphere is a sign of the “correct”behavior of their intensities and radial velocities with orbital phase.
Gies et al.(2002),Hillwig et al.(2004)detected weak absorption lines of TiII,FeII,CrII,SrII,CaI,FeI in the blue region4100–4600?A of the spectrum.They observed SS433near the primary eclipse and in precession phases where the disk is the most”face-on”.These lines are be-lieved to belong to the donor star of SS433with an A-type spectrum.
One may also try to search for stellar lines in the yellow and red regions among the weakest metallic lines,however these regions are crowded with strong moving lines of hy-drogen and HeI formed in the relativistic jets.The moving lines are extremely variable and have structured pro?les. This complicates the search for weak lines and the study of their behavior from date to date.For this reason we have investigated only the bluer parts of our spectra.The most informative region for stellar line studies is4200–4340?A where no strong emission lines and no appreciable moving lines appear at these precession phases.
The4100–5300?A SS433spectra have been com-pared with those of the known galactic supergiants with di?erent temperatures.We used publicly available (http://webast.ast.obs-mip.fr/stelib/)library of stellar spectra(STELIB,Le Borgne et al.2003).These spectra were taken with the same spectral resolution(3?A)as our spectra of SS433.For identi?cation of lines we have used spectral atlases of Deneb(A2Iae)(Albayrak et al.2003) and o Pegasi(A1IV)(Gulliver et al.2004).Spectra of SS433summed over one night were used for the line iden-ti?cation.
7.Spectral type of the optical star
Fig.15shows spectra of four supergiants and two SS433 spectra taken outside and inside the eclipse,each aver-aged over two nights.The eclipse-out spectrum was aver-aged over nights09.05.2003and12.05.2003corresponding to orbital phases0.89and0.12evenly spaced from the eclipse center(the top spectrum).The in-eclipse spectrum was averaged over nights28.04.2003and11.05.2003cor-responding to orbital phase0.05(spectrum second from the top in the?gure).The supergiants shown in Fig.15 are HD36673(F0I,7,200K),HD39866(A2I,8,400K), HD87737(A0I,9,700K)and HD164353(B5I,22,000K). All spectra were normalized and shifted along the vertical axis for better visualization.
With our spectral resolution,practically all absorp-tion lines appear as complex blends.In Fig.15the lines observed out of the eclipse are marked with short vertical bars;those seen in the eclipse or present in both spectra are marked with long bars.One can see that the strongest absorptions in the spectra of supergiants are also present in SS433and these absorption lines are deeper in the spec-trum during the primary minimum.FeIIλ4233emission is seen(FWHM～10?A),CIIλ4267and NIIIλ4196,4200+ HeIIλ4200emissions are also marginally present.
The intensity of absorption lines during the eclipse al-lows us to estimate the e?ective temperature of the donor star to be T<9000K.This limitation was obtained from the fact that the absorption lines in SS433cannot be deeper than those in spectra of supergiants,because the accretion disk is not totally eclipsed in the primary minima.The relative intensities of the strongest metallic absorption lines indicate a temperature of T=8000±500 K,implying that the optical spectral class of the compan-ion is A5-A7I.
10Cherepashchuk et al.:INTEGRAL observations of SS433
Table4.Journal of spectral observations
Date JD(mid)Orbital Precession N Exposure Range(?A)
2450000+phase phase
(sec)
Fig.15.Spectra of SS433and spectra of four supergiants of known temperatures(Le Borgne et al.,2003)for a comparison.The top spectrum was taken outside the eclipse and averaged over nights09.05.2003and12.05.2003 (evenly spaced from the eclipse center orbital phases0.89and0.12).The second from the top spectrum was taken inside the eclipse and averaged over nights28.04.2003and11.05.2003(the orbital phase0.05).
7.1.Evidence for a heating e?ect in the illuminated
hemisphere
The analysis of di?erent absorption lines of the optical star reveals a strong heating e?ect in the illuminated star’s at-mosphere.During the disk eclipse egress low-excitation absorption lines strongly weaken.The stellar hemisphere illuminated by the bright accretion disk in SS433prob-ably has a temperature of～20,000K,as the presence of CIIλ4267absorption+emission line suggests(the top spectrum in Fig.15).This absorption line is the strongest one in this spectral region among supergiants with tem-peratures T>15,000K.The evolution of the blendλ4273 (FeIλ4271.7+FeIIλ4273.3+CrIIλ4275.5)is seen:in the eclipse center the low-excitation FeI line is stronger,while out of the eclipse FeII+CrII lines are enhanced.Other FeI lines also appear only in the eclipse.
Cherepashchuk et al.:INTEGRAL observations of SS433
11
For comparison,spectra of two supergiants(8,400K and
optical star is traced by di?erent absorption lines(vertical bars).On the left panel,the third from bottom is the SS433 spectrum averaged over all nights with taking into account the radial velocity shifts from Fig.18.See text for more details.
These e?ects are illustrated by Fig.16,in which spectra of the standard stars with e?ective tempera-tures8,400K and22,000K are shown together with spectra of SS433obtained on9.05,10.05,28.04+11.05, 12.05and13.05(orbital eclipses fell on nights10.05and 28.04+11.05).The orbital phase rises from bottom to top in the?gure.There are emission lines in these spectral fragments—the broad structured emission of CIIλ4267, and stronger emissions FeIIλ5169+MgIλ5167,5173and FeIIλ5197.Note that emission lines,which presumably are formed in the disk wind,should move blueward(in phase with the compact object)in the orbital phases of our observations.In contrast,absorption lines,which are formed in the donor photosphere,must move redward dur-ing our observations.The strength of the CIIλ4267ab-sorption component(marked by vertical bars in Fig.16) increases notably out of the eclipse.The complex blend λ4273(FeI+FeII+CrII)is marked by the dotted lines in the?gure.
Fig.16illustrates absorption lines(marked by the vertical bars)—the blendλ4314of TiIIλ4313+FeIIλ4314+TiIIλ4315;ScIIλ4320line and the blend ScIIλ4325+FeIλ4326,4327.However the last blend may be distorted by the strong blue wing of Hγin the middle of eclipse.Other absorption lines shown in Fig.16(right panel)areλ5154(TiII+FeII)andλ5227 (TiII+FeI).It is seen that these lines shift redward with time.
In Fig.16we also show the spectrum of SS433averaged over all nights of observations(the third from bottom). When averaging spectra obtained on individual nights we shifted them to zero velocity according to the radial veloc-ity curve from Fig.18.The average spectrum has a better signal-to-noise ratio.All the absorpton lines remain in the spectrum and they are similar to the corresponding lines in the spectrum of the standard supergiant(8,400K).The shallow emission line(presumably CIIλ4267)has an ab-sorption component.In our recent spectral observations of SS433,which were carried out around primary mimima on August24,2004and September6,2004(the preces-sion phase is the same,i.e.the maximum disk opening) we con?rmed the presence of the absorption lines studied in this paper.Both the spectral resolution and signal-to-noise ratio are better in the new observations.Analysis of the new data will be published elsewhere.
12Cherepashchuk et al.:INTEGRAL observations of
SS433
Fig.17.Radial velocity curve of the optical companion of SS433obtained from 4individual absorption lines over 6
nights.
Fig.18.Mean radial velocity curve of the optical com-panion of SS433measured from 22individual absorption lines.The accretion disk radial velocities as measured by HeII λ4686emission (Fabrika and Bychkova,1990)is shown by the dotted line.
7.2.Measurements of the radial velocity of the optical
star
It is important to stress that the strongest absorptions (FeII,HeI)are disfavored for the optical star radial veloc-ity analysis,as they most probably formed in the powerful out?owing disk wind (Fabrika et al.1997).We studied ra-dial velocities of weak absorption lines of metals.It is easy to confuse the line identi?cation when one traces a line from date to date because of the spectral variability and orbital motion of the companions.In Fig.17we present individual absorption line radial velocities for four best-suited lines averaged over one night,as a function of the orbital phase for 6nights.
The radial velocity curve measured by the most reli-able collection of 22absorption lines in the spectral range 4200-5300?A is shown in Fig.18.Note that with our spec-
tral resolution the absorption lines in the SS433spectrum
are seen as blends containing 2-3lines,and we measured their relative radial velocities because of unknown ”labo-ratory”wavelengths of the blends.Relative intensities of the lines change from date to date through the eclipse.For this reason we measured only those lines and on only those dates where the lines were the most convincingly detected.The radial velocity curve (Fig.18)has been obtained by coadding radial velocity curves of individual lines,and the zero radial velocity of all lines on 11.05.2003(the orbital phase 0.048)was adopted.If a line was not detected on 11.05.2003,the zero radial velocity was as-sumed for 28.04.2003as well (the orbital phase 0.054).If the measured radial velocity on 11.05.2003disagreed with the whole radial velocity curve of a given line,an addi-tional shift for the curve was applied.However no shifts in excess of 20km/s were done.This is the reason why the radial velocity error in 11.05.2003is small,but not zero.
Thus,the radial velocity curve for absorption lines in Fig.18consists of individual radial velocity curves.Each point of the curve includes from 10to 17individual mea-surements.Most measurements were carried out at the primary minimum as there the absorption lines are deeper.
The derived radial velocity semi-amplitude of the donor star is K v =132±9km/s,the gamma-velocity of the binary system is v γ=14km/s with a formal ?t uncertainty of 2km/s.The absorption line radial veloc-ity transition through the γ-velocity occurs at the mid-dle of the optical eclipse (φb =0.07),con?rming that the lines actually belong to the donor star.Note that in the gamma-velocity v γand in the transition phase φb some systematic errors can be present because of the method used.However they are less than 30km/s (no bigger shifts were applied to radial velocity curves of individual lines)and 0.05correspondingly.The main observational bias in studying radial velocities of the donor star is the faintness of absorption lines outside the primary minima and strong intrinsic spectral variability of SS433.To con?rm the de-rived radial velocity curve further spectral observations are needed.
Our results con?rm the earlier determination of K v by Gies et al.(2002)which was carried out also at the maximum disk opening phases.Note that spectroscopic observations by Charles et al.(2004)were performed at the crossover phase of SS433when the accretion disk is seen edge-on.Such a phase is disfavored for the donor star radial velocity analysis as strong gas out?ows contaminate the disk plane;selective absorption in this gas a?ects the true radial velocity of the donor star.
The heating e?ect of the donor star also distorts the radial velocity semi-amplitude.The analysis (Wade and Horne 1988,Antokhina et al.2005)indicates that the true value of the semi-amplitude of the radial velocity curve as derived from these absorption lines can be reduced to ～85km/s (see below).
Recently Hillwig et al.(2004)obtained an estimate of the radial velocity amplitude of the donor star K v =45±6km/s and the gamma-velocity v γ=65±3km/s.In our
Cherepashchuk et al.:INTEGRAL observations of SS433
13
Fig.19.The spectroscopic center of the normal star (cir-cle)heated by its companion is shifted with respect to the gravity center (cross).The arc arrows indicate the orbital motion.Zone ”A”is the most e?ectively illuminated by the compact source,disk and jet.Zone ”B”is also illumi-nated by outer parts of the disk and jet and by scattered radiation.The low excitation potential absorption lines used for radial velocity measurements can be formed in zone ”C”which is not heated.Due to this e?ect,the spec-troscopically derived radial velocity of the optical star is overestimated.
opinion,some strong lines (which actually are shell-like lines on the background of faint emission)could contribute to the radial velocity cross-correlations of Hillwig et al.(2004).For example,the two strongest lines in their Fig.5FeII λ4550and FeII λ4584are in emission in our spectra in the middle of eclipse.
The KPNO-2003observations of Hillwig et al.(2004)were made in the orbital phases 0.85-1.07.Absorption lines formed in the rotating and extended envelope of the donor could be probably observed.In these orbital phases,the side of the envelope projected onto the strong continuum source (the accretion disk)moves away from the observer.Then the amplitude of the line shift can be expected to be ～1/2V equat ～60km/s.This might explain the posi-tive shift of the system velocity +65km/s found by those authors.
8.Implications for binary masses
Comparison of radial velocities of the accretion disk (K x =175km/s,Fabrika and Bychkova 1990)and optical star (K v =132km/s)yields the mass ratio in the SS433sys-tem q =m x /m v =K v /K x =0.75(here m x and m v stand for relativistic object and optical star mass,respectively).Taken at face value,these q,K v values would lead to the optical star mass function f v ≈3.12M ⊙and the binary component masses m x =18M ⊙,m v =24M ⊙.However,such a large mass ratio is in a strong disagreement with the observed duration of the X-ray eclipse,which suggests a much smaller mass ratio q ～0.2?0.3.We stress that the binary inclination angle in SS433(i =78o .8)is ?xed from the analysis of moving emission lines.
There are two possibilities:(1)either the model we used to ?t X-ray eclipses should be modi?ed,or (2)the value of K x and K v are in?uenced by additional phys-ical e?ects.Although there are some reasons to modify
the model (e.g.,the asymmetric shape of the hard X-ray eclipse,which may suggest an asymmetric wind out?ow from the illuminated part of the optical star and wind-wind collision),we shall consider here only the second pos-sibility.The reason is that the actual value of K v should be decreased in order to account for the observed heating e?ect.
Let us assume the mass ratio in the system to be q =0.3,as with this value we can satisfactorily describe the width of X-ray eclipse and the observed X-ray preces-sion amplitude (see Fig.10).Taking K v =132km/s yields f v ≈3.1M ⊙and m x =62M ⊙,m v =206M ⊙,K x =440km/s.Clearly,this is an unacceptable model.Now let us decrease K v down to 85km/s,the lower limit that follows from a more accurate treatment of the heating e?ect in the radial velocity curve analysis (Wade and Horne 1988,Antokhina et al.2005).This would yield a better ?t with m x =17M ⊙,m v =55M ⊙,and K x =283km/s,still too high to be acceptable.Less than half of the stellar surface is su?ciently cool to give the absorption lines un-der study (e.g.due to sideway heating from scattered UV radiation in the strong accretion disk wind).This addi-tionally decreases the value of the actual radial velocity semi-amplitude.Fig.19illustrates these considerations.
So taking,for example,K v =70km/s and q =0.3yields the optical star mass function f v =0.46M ⊙,binary masses m x =9M ⊙,m v =30M ⊙and the optical star ra-dius R v ～40R ⊙.This radius is compatible with a typical bolometric luminosity of a 30M ⊙A5-A7supergiant with T eff ～8500K.In this solution,K x ?233km/s,larger than the measured value 175km/s,but the true value of K x may be a?ected by the strong accretion disk wind.
9.Discussion
The interpretation of the binary parameters presented above is strongly based on the binary mass ratio q =0.3as inferred from modeling the INTEGRAL observations of the hard X-ray eclipse with account of the observed ampli-tude (～4)of the hard X-ray precessional variability of the system.The model we use (an optical star ?lling its Roche lobe +thick accretion disk with a hot corona)is simplistic and cannot perfectly reproduce the apparent asymmetric shape of the X-ray eclipse.In the real situation,an ad-ditional X-ray absorption by out?owing gaseous streams,extended stellar envelope or wind seems quite plausible.If we interpret the complex shape of the hard X-ray egress as being due to additional variable absorption e?ects,we obtain the geometry of the hard X-ray emitting region in the form of an extended oblate corona over the accretion disk.However,a straightforward interpretation of the joint RXTE+INTEGRAL spectrum of the source observed in March 2004is also possible by a single thermal emission with a temperature of ～30keV.No additional emitting region is required to ?t this broadband X-ray spectrum.
There are two possible solutions.First,we could try to describe the observed hard X-ray spectrum by a more complex model involving two components,a hot corona
14Cherepashchuk et al.:INTEGRAL observations of SS433
+cooler thin jet radiating in the standard X-ray band. Second,we could try to accept the thin cooling jet inter-pretation of the X-ray spectrum,but then would have to admit a di?erent shape of the X-ray eclipse.Our modeling shows that a thin short jet could reproduce the observed amplitude(～4)of hard X-ray precessional variability in SS433.In that case,the shape of the X-ray eclipse must be more sharp,with shorter ingress/egress times than ac-tually observed(cf.Fig.9).If we look at the data,such a shape can indeed be found at the egress phase of the eclipse(see Fig.6).The(apparently longer)ingress time could be due to additional(apart from the opaque star body)absorption of hard X-ray emission by an optically thick gaseous stream out?owing from the optical star. Apparently the same smooth ingress and egress shape of the eclipse in softer X-rays(the Ginga and ASCA data) in that case could be due to the soft X-ray emitting region located further upstream of the jets.This interpretation also explains the shallower soft X-ray eclipse.
Clearly,in this situation we need more observations of the hard X-ray eclipse to con?rm the asymmetric ingress/egress eclipse shape and?atness of its bottom. We hope to do this in future INTEGRAL observations of SS433.
10.Conclusions
The results of the INTEGRAL observations of the peculiar binary system SS433in2003-2004can be summarized as follows.
1.Hard X-ray emission up to～100keV was dis-covered from this superaccreting microquasar with un-eclipsed hard X-ray luminosity close to the maximum opening precession phase L x(18?60keV)～4×1035erg/s, L x(60?120keV)～2×1035erg/s(assuming the5kpc dis-tance to SS433),which is about10%of the soft X-ray jet luminosity.
2.Persistent precessional variability in hard X-rays was discovered with the maximum to minimum?ux ratio～4, which is twice as large as in the softer X-ray band.
3.The observed hard X-ray orbital eclipse is found to be in phase with the optical and near infrared eclipses. The hard X-ray eclipse is observed to be at least two times deeper than the soft X-ray eclipse.The width of the X-ray eclipse increases with energy,which is opposite to what is observed in classical X-ray binary systems.
4.The broadband X-ray spectrum2-100keV of SS433 simultaneously obtained by INTEGRAL and RXTE in March2004when the source was in its?aring state can be?tted by bremsstrahlung emission from optically thin plasma with a temperature kT≈30keV.
5.Optical spectroscopic observations of SS433on the SAO6-m telescope which were performed in the frame-work of the multiwavelength INTEGRAL campaign of the source con?rmed the spectral class of the optical star to be A5-A7I.The radial velocity curve of the optical com-ponent was obtained with a semi-amplitude K v=132±9 km/s near the maximum disk opening precession phase (T3).The spectroscopic data revealed a heating e?ect of the hemisphere of the optical star illuminated by the ac-cretion disk.
6.From the analysis of the hard X-ray eclipse and pre-cession variability in SS433we estimate the mass ratio in this binary system to be q～0.3.This mass ratio and radial velocity measurements corrected for the heating ef-fect enable us to evaluate the masses of the optical and compact star in SS433to be M v≈30M⊙,M x≈9M⊙,re-spectively.This?nding lends further support to the pres-ence of a black hole in this peculiar superaccreting galactic microquasar.
Acknowledgements.The authors thank E.M.Churazov for de-veloping methods and analysis of the IBIS data and soft-ware.We acknowledge Vitaly Goranskij for comments and discussion.We also ackhowledge E.K.She?er,S.A.Trushkin, V.M.Lyuty,S.Yu.Shugarov,N.A.Katysheva,A.A.Lutovinov for discussions and collaboration.We especially thank Dr.D. Hannikainen for providing us with data on SS433X-ray egress observations and M.G.Revnivtsev for processing RXTE spec-tra of SS433.IFB thanks the Turkish National Observatory night assistants Kadir Uluc and Murat Parmaksizoglu for their support in the photometric SS433observations.A.N.Burenkov is acknowledged for help in spectral observations.The work of SNF is partially supported by the RFBR grant04-02-16349. The work of KAP,ANT and IEP is partially supported by the RFBR grant04-02-16720.The work of KAP was also par-tially supported by the Academy of Finland through grant 100488.NIS and IEP acknowledge the?nancial support from the RFBR by the grant03-02-16068.SVM and ES acknowl-edge the European Space Agency for support and the Integral Science Data Center(Versoix,Switzerland)for providing com-puting facilities.ANT also acknowledges the?nancial sup-port from the Russian Federation President Grant Program through grant MK-895.2003.02.The work of AMCh,EAA, EVS and ANT was partially supported through the grant of Leading Scienti?c Schools of Russia NSh-388.2003.2and RFBR grant02-02-17524.NAS and IFB acknowledge the support of RFBR grant02-02-17174and grant of Leading Scienti?c Schools of Russia NSh-1789.2003.2.EAB was partially sup-ported by the RFBR grant03-02-16133.The IR observations (YNG and AAA)are partially supported by the RFBR grant 03-02-17223a,the Program of Prezidium RAN”Nonstationary Processes in Astronomy”and the FBNTP”Astronomy”.We are grateful to the anonymous referee for the useful remarks which helped us to improve and clarify the article. References
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如何写先进个人事迹 篇一：如何写先进事迹材料 如何写先进事迹材料 一般有两种情况：一是先进个人，如先进工作者、优秀党员、劳动模范等；一是先进集体或先进单位，如先进党支部、先进车间或科室，抗洪抢险先进集体等。无论是先进个人还是先进集体，他们的先进事迹，内容各不相同，因此要整理材料，不可能固定一个模式。一般来说，可大体从以下方面进行整理。 (1)要拟定恰当的标题。先进事迹材料的标题，有两部分内容必不可少，一是要写明先进个人姓名和先进集体的名称，使人一眼便看出是哪个人或哪个集体、哪个单位的先进事迹。二是要概括标明先进事迹的主要内容或材料的用途。例如《王鬃同志端正党风的先进事迹》、《关于评选张鬃同志为全国新长征突击手的材料》、《关于评选鬃处党支部为省直机关先进党支部的材料》等。 (2)正文。正文的开头，要写明先进个人的简要情况，包括：姓名、性别、年龄、工作单位、职务、是否党团员等。此外，还要写明有关单位准备授予他(她)什么荣誉称号，或给予哪种形式的奖励。对先进集体、先进单位，要根据其先进事迹的主要内容，寥寥数语即应写明，不须用更多的文字。 然后，要写先进人物或先进集体的主要事迹。这部分内容是全篇材料
的主体，要下功夫写好，关键是要写得既具体，又不繁琐；既概括，又不抽象；既生动形象，又很实在。总之，就是要写得很有说服力，让人一看便可得出够得上先进的结论。比如，写一位端正党风先进人物的事迹材料，就应当着重写这位同志在发扬党的优良传统和作风方面都有哪些突出的先进事迹，在同不正之风作斗争中有哪些突出的表现。又如，写一位搞改革的先进人物的事迹材料，就应当着力写这位同志是从哪些方面进行改革的，已经取得了哪些突出的成果，特别是改革前后的．经济效益或社会效益都有了哪些明显的变化。在写这些先进事迹时，无论是先进个人还是先进集体的，都应选取那些具有代表性的具体事实来说明。必要时还可运用一些数字，以增强先进事迹材料的说服力。 为了使先进事迹的内容眉目清晰、更加条理化，在文字表述上还可分成若干自然段来写，特别是对那些涉及较多方面的先进事迹材料，采取这种写法尤为必要。如果将各方面内容材料都混在一起，是不易写明的。在分段写时，最好在每段之前根据内容标出小标题，或以明确的观点加以概括，使标题或观点与内容浑然一体。 最后，是先进事迹材料的署名。一般说，整理先进个人和先进集体的材料，都是以本级组织或上级组织的名义；是代表组织意见的。因此，材料整理完后，应经有关领导同志审定，以相应一级组织正式署名上报。这类材料不宜以个人名义署名。 写作典型经验材料-般包括以下几部分： (1)标题。有多种写法，通常是把典型经验高度集中地概括出来，一
How to manage time Time treats everyone fairly that we all have 24 hours per day. Some of us are capable to make good use of time while some find it hard to do so. Knowing how to manage them is essential in our life. Take myself as an example. When I was still a senior high student, I was fully occupied with my studies. Therefore, I hardly had spare time to have fun or develop my hobbies. But things were changed after I entered university. I got more free time than ever before. But ironically, I found it difficult to adjust this kind of brand-new school life and there was no such thing called time management on my mind. It was not until the second year that I realized I had wasted my whole year doing nothing. I could have taken up a Spanish course. I could have read ten books about the stories of successful people. I could have applied for a part-time job to earn some working experiences. B ut I didn’t spend my time on any of them. I felt guilty whenever I looked back to the moments that I just sat around doing nothing. It’s said that better late than never. At least I had the consciousness that I should stop wasting my time. Making up my mind is the first step for me to learn to manage my time. Next, I wrote a timetable, setting some targets that I had to finish each day. For instance, on Monday, I must read two pieces of news and review all the lessons that I have learnt on that day. By the way, the daily plan that I made was flexible. If there’s something unexpected that I had to finish first, I would reduce the time for resting or delay my target to the next day. Also, I would try to achieve those targets ahead of time that I planed so that I could reserve some more time to relax or do something out of my plan. At the beginning, it’s kind of difficult to s tick to the plan. But as time went by, having a plan for time in advance became a part of my life. At the same time, I gradually became a well-organized person. Now I’ve grasped the time management skill and I’m able to use my time efficiently.
英语演讲稿：未来的工作 这篇《英语演讲稿范文：未来的工作》，是特地，希望对大家有所帮助！ 热门演讲推荐：竞聘演讲稿 | 国旗下演讲稿 | 英语演讲稿 | 师德师风演讲稿 | 年会主持词 | 领导致辞 everybody good afternoon:. first of all thank the teacher gave me a story in my own future ideal job. everyone has a dream job. my dream is to bee a boss, own a pany. in order to achieve my dreams, i need to find a good job, to accumulate some experience and wealth, it is the necessary things of course, in the school good achievement and rich knowledge is also very important. good achievement and rich experience can let me work to make the right choice, have more opportunities and achievements. at the same time, munication is very important, because it determines whether my pany has a good future development. so i need to exercise their municative ability. i need to use all of the free time to learn
统计学名词解释 第一章绪论 1.随机变量：在统计学上，把取值之间不能预料到什么值的变量。 2.总体：又称母全体、全域，指具有某种特征的一类事物的全体。 3.个体：构成总体的每个基本单元称为个体。 4.样本：从总体中抽取的一部分个体，称为总体的一个样本。 5.次数：指某一事件在某一类别中出现的数目，又称为频数。 6.频率：又称相对次数，即某一事件发生的次数被总的事件数目除，亦即某一数据出现的次数被这一组数据总个数去除。 7.概率：某一事物或某一情在某一总体中出现的比率。 8.观测值：一旦确定了某个值。就称这个值为某一变量的观测值。 9.参数：又称为总体参数，是描述一个总体情况的统计指标。 10.统计量：样本的那些特征值叫做统计量，又称特征值。 第二章统计图表 1.统计表：是由纵横交叉的线条绘制，并将数据按照一定的要求整理、归类、排列、填写在内的一种表格形式。一般由表号、名称、标目、数字、表注组成。 2.统计图：一般采用直角坐标系，通常横轴表示事物的组别或自变量x，称为分类轴。纵轴表示事物出现的次数或因变量，称为数值轴。一般由图号及图题、图目、图尺、图形、图例、图组成。 3.简单次数分布表：依据每一个分数值在一列数据中出现的次数或总计数资料编制成的统计表，适合数据个数和分布范围比较小的时候用。 4.分组次数分布表：数据量很大时，应该把所有的数据先划分在若干区间，然后将数据按其数值大小划归到相应区域的组别内，分别统计各个组别中包括的数据个数，再用列表的形式呈现出来，适合数据个数和分布范围比较大的时候用。 5.分组次数分布表的编制步骤： （1）求全距 （2）定组距和组数 （3）列出分组组距 （4）登记次数 （5）计算次数 6.分组次数分布的意义： （1）优点：A．可将杂乱无章数据排列成序，以发现各数据的出现次数及分布状况。B．可显示一组数据的集中情况和差异情况等。 （2）缺点：原始数据不见了，从而依据这样的统计表算出的平均值会与用原始数据算出的值有出入，出现误差，即归组效应。 7.相对次数分布表：用频数比率或百分数来表示次数 8.累加次数分布表：把各组的次数由下而上，或由上而下加在一起。最后一组的累加次数等于总次数。 9.双列次数分布表：对有联系的两列变量用同一个表表示其次数分布。
小学生个人读书事迹简介怎么写800字 书,是人类进步的阶梯,苏联作家高尔基的一句话道出了书的重要。书可谓是众多名人的“宠儿”。历来,名人说出关于书的名言数不胜数。今天小编在这给大家整理了小学生个人读书事迹,接下来随着小编一起来看看吧! 小学生个人读书事迹1 “万般皆下品,惟有读书高”、“书中自有颜如玉,书中自有黄金屋”,古往今来,读书的好处为人们所重视,有人“学而优则仕”,有人“满腹经纶”走上“传道授业解惑也”的道路……但是,从长远的角度看,笔者认为读书的好处在于增加了我们做事的成功率,改善了生活的质量。 三国时期的大将吕蒙,行伍出身,不重视文化的学习,行文时,常常要他人捉刀。经过主君孙权的劝导,吕蒙懂得了读书的重要性,从此手不释卷,成为了一代儒将,连东吴的智囊鲁肃都对他“刮目相待”。后来的事实证明,荆州之战的胜利,擒获“武圣”关羽,离不开吕蒙的“运筹帷幄,决胜千里”,而他的韬略离不开平时的读书。由此可见,一个人行事的成功率高低,与他的对读书,对知识的重视程度是密切相关的。 的物理学家牛顿曾近说过,“如果我比别人看得更远,那是因为我站在巨人的肩上”,鲜花和掌声面前,一代伟人没有迷失方向,自始至终对读书保持着热枕。牛顿的话语告诉我们,渊博的知识能让我们站在更高、更理性的角度来看问题,从而少犯错误,少走弯路。
读书的好处是显而易见的,但是,在社会发展日新月异的今天,依然不乏对读书,对知识缺乏认知的人,《今日说法》中我们反复看到农民工没有和用人单位签订劳动合同,最终讨薪无果;屠户不知道往牛肉里掺“巴西疯牛肉”是犯法的;某父母坚持“棍棒底下出孝子”,结果伤害了孩子的身心,也将自己送进了班房……对书本,对知识的零解读让他们付出了惨痛的代价,当他们奔波在讨薪的路上,当他们面对高墙电网时,幸福,从何谈起?高质量的生活,从何谈起? 读书,让我们体会到“锄禾日当午,汗滴禾下土”的艰辛;读书,让我们感知到“四海无闲田,农夫犹饿死”的无奈;读书,让我们感悟到“为报倾城随太守,西北望射天狼”的豪情壮志。 读书的好处在于提高了生活的质量,它填补了我们人生中的空白,让我们不至于在大好的年华里无所事事,从书本中,我们学会提炼出有用的信息,汲取成长所需的营养。所以,我们要认真读书,充分认识到读书对改善生活的重要意义,只有这样,才是一种负责任的生活态度。 小学生个人读书事迹2 所谓读一本好书就是交一个良师益友,但我认为读一本好书就是一次大冒险,大探究。一次体会书的过程,真的很有意思,咯咯的笑声,总是从书香里散发;沉思的目光也总是从书本里透露。是书给了我启示,是书填补了我无聊的夜空,也是书带我遨游整个古今中外。所以人活着就不能没有书,只要爱书你就是一个爱生活的人,只要爱书你就是一个大写的人,只要爱书你就是一个懂得珍惜与否的人。可真所谓
统计学符号意义及读音 按照国家标准GB3358-82《统计学名词及符号》的有关规定书写，常用如下: (1) 样本的算术平均数用英文小与x (中位数仍用M) ; (2) 标准差用英文小与s; (3) 标准误用英文小写Sx; (4) t检验用英文小写t; (5) F检验用英文大写F; (6) 卡方检验用希文小写字X2; (7) 相关系数用英文小写r; (8) 白由度用希文小写u; (9) 概率用英文大写P (P值前应给出具体检验值，如t值、字2值、q 值等)。 以上符号均用斜体。 拉丁字母 假定均数X样本均数Y Y变量；变量值，观察值；回归中的应（因）变量y Y变换后的变量或变量值
Y样本均数 希腊字母 符号名称符号名称 α检验水准，显着性水准；第一类错误的概率1-α可信度，置信度 β第二类错误的概率；总体回归系数1-β检验效能，把握度 ν（n′）自由度π总体率 μ总体均数ρ总体相关系数 Σ求和的符号σ总体标准差 σ2总体方差χ2χ2检验的统计量 符号名称符号名称 A X2检验中的实际频数A,b,c,d四格表中的实际频 a样本回归直线在Y轴上的截距b样本回归系数 C校正数；常量；x2检验中的列（栏）数CI可信区间 -------------------------------------------------------------------------------- CL可信限CV变异系数 --------------------------------------------------------------------------------
d两数之差值d差值的均数 f（X）连续型分布密度函数，密度f观察频数，实际频数 G几何均数；对数似然比检验的统计量H调和均数；H检验的统计量 Hg检验假设，无效假设H1备择假设 i组距；行次L下限 M中位数N有限总体含量；各样本含量的总和 n样本含量；各样本含量的总和P概率 P（1）单侧检验的概率P（2）双侧检验的概率 Px第x百分位数P样本率 R极差；样本复相关系数；x2检验中的行数r样本相关系数 RR相对危险度s样本标准差 S2样本方差sb样本回归系数的标准误 S02合并样本方差sd（样本）差值的标准差 s-d（样本）差值均数的标准误sp样本率的标准误 Sp1-p2两样本率差的标准误sX样本均数的标准误 SD标准差SE标准误
关于坚持的英语演讲稿 Results are not important, but they can persist for many years as a commemoration of. Many years ago, as a result of habits and overeating formed one of obesity, as well as indicators of overall physical disorders, so that affects my work and life. In friends to encourage and supervise, the participated in the team Now considered to have been more than three years, neither the fine rain, regardless of winter heat, a day out with 5:00 time. The beginning, have been discouraged, suffering, and disappointment, but in the end of the urging of friends, to re-get up, stand on the playground. 成绩并不重要，但可以作为坚持多年晨跑的一个纪念。多年前，由于庸懒习惯和暴饮暴食，形成了一身的肥胖，以及体检指标的全盘失常，以致于影响到了我的工作和生活。在好友的鼓励和督促下，参加了晨跑队伍。现在算来，已经三年多了，无论天晴下雨，不管寒冬酷暑，每天五点准时起来出门晨跑。开始时，也曾气馁过、痛苦过、失望过，但最后都在好友们的催促下，重新爬起来，站到了操场上。 In fact, I did not build big, nor strong muscles, not a sport-born people. Over the past few years to adhere to it, because I have a team behind, the strength of a strongteam here, very grateful to our team, for a long time, we encourage each other, and with sweat, enjoying common health happy. For example, Friends of the several run in order to maintain order and unable to attend the 10，000 meters race, and they are always concerned about the brothers and promptly inform the place and time, gives us confidence and courage. At the same time, also came on their own inner desire and pursuit for a good health, who wrote many of their own log in order to refuel for their own, and inspiring. 其实我没有高大身材，也没健壮肌肉，天生不属于运动型的人。几年来能够坚持下来，因为我的背后有一个团队，有着强大团队的力量，在这里，非常感谢我们的晨跑队，长期以来，我们相互鼓励着，一起流汗，共同享受着健康带来的快
名词解释 统计总体：指客观存在的、在同一性质基础上结合起来的许多个别单位的整体。统计总体的特征：同质性、差异性、大量性。 总体单位：个体，指构成总体的各个单位。 统计指标：简称指标，用来反映社会经济现象总体的数量特征的概念及其数值。任一概念都包含指标名称和指标数值。特征有总体性、数量性、综合性、具体性。 统计标志：在统计中，总体单位所具有的属性或特征的名称。标志是统计研究的起点，总体单位是标志的载体，是标志的承担者，统计研究是从登记标志开始的，并通过对标志的综合来反映总体的数 量特征。可分为品质标志和数量标志，或不变标志和变异标志。 统计调查：就是根据统计研究的预定目的、要求和任务，运用各种科学的调查方法，有计划、有组织地搜集有关现象的各个单位的资料，对客观事实进行登记，取得真实可靠的原始资料的工作过程。 统计调查是整个统计工作的基础环节。统计调查的好坏，将影响统计资料的正确与否，从而影 响统计质量。统计调查的要求：准确性、及时性、全面性、系统性。 普查：是根据统计任务的特定目的而专门组织的一次性全面调查。调查范围：1.属于一定时点的社会经济现象的总量（如人口普查）。2.反映一定时期现象的总量（如出生人口总数）。优点：所获资料 更详细，有较高的准确性和时效性。缺点：工作量大，花费时间长，耗费大量的人力、物力和 财力。主要作用：在于掌握某些关系国计民生、国情国力的数据，获得比较准确的信息。 抽样调查：指从所要研究的总体中，按照随机原则，抽取部分单位进行调查，并将调查整理得出的数量特征，用以推断总体综合数量特征的一种非全面调查组织形式。特点：随机性、推断性。优点： 经济性、时效性、准确性、灵活性。应用范围：①对总体不可能或不必要进行全面调查，但要 掌握总体某些现象的全面数值②用抽样调查资料修正全面调查资料。作用：①承担全面调查无 法或很难承担的调查任务。如气象调查。②与全面调查结合，可以发挥相互补充、校对的作用。 ③进行生产过程的质量控制。④用来检验总体特征的某些假设，为行动决策提供依据。抽样调 查的组织形式：纯随机抽样、机械抽样、类型抽样、整群抽样、阶段抽样。 典型调查：根据调查目的和要求，在对研究总体作全面分析后，有意识地从中选取少数具有代表性的单位进行深入调查研究的一种非全面调查。优点：节省人力、物力，既可搜集统计资料，又可分析 研究问题。缺点：资料不齐全，缺乏代表性。主要作用：1.弥补全面调查不足（获取其它统计调 查方法不能得到的统计资料；补充完善统计报表；验证全面调查数据的真实性。2.进行估算某些 指标数值。 重点调查：是一种非全面调查，是在调查对象中选择重点单位进行的调查，但这部分重点单位占总体的绝大比重。优点：省事、省力，能用较少的代价及时搜集到总体的基本情况和基本趋势。缺点： 资料受重点单位影响大，资料一般不齐全。 统计整理：就是根据统计研究的预定目的，对所搜集到的资料进行科学加工，使之条理化、系统化，建立统计数据库，以满足多方面、多层次的反复需要的工作过程。作用：统计整理是统计工作过程 的重要阶段，它是实现从个体单位标志值过渡到总体数量特征值的必经阶段，是统计分析的前 提。其质量的好坏会直接影响统计分析的效果。 绝对指标：又称总量指标，有时也称绝对数。是用来说明一定社会经济现象的规模、水平的总量。它包括总体总量和标志总量。 相对指标：又称相对数，是两个相联系指标的比值。作分母的指标为基数，分子为表数。通过相对指标可反映现象间的相互关系和对比关系。一般分为有名数和无名数。种类有：计划完成相对指标、 结构相对指标、比较相对指标、动态相对指标、强度相对数。 平均指标：又称统计平均数，它是度量频率分布集中趋势或中心位置的指标。也是社会经济统计中最常用的综合指标。它是在同质总体内各总体单位某一数量标志的一般水平。一般有两种分类：静态 平均数、动态平均数。
1.How to build a business that lasts100years 0:11Imagine that you are a product designer.And you've designed a product,a new type of product,called the human immune system.You're pitching this product to a skeptical,strictly no-nonsense manager.Let's call him Bob.I think we all know at least one Bob,right?How would that go? 0:34Bob,I've got this incredible idea for a completely new type of personal health product.It's called the human immune system.I can see from your face that you're having some problems with this.Don't worry.I know it's very complicated.I don't want to take you through the gory details,I just want to tell you about some of the amazing features of this product.First of all,it cleverly uses redundancy by having millions of copies of each component--leukocytes,white blood cells--before they're actually needed,to create a massive buffer against the unexpected.And it cleverly leverages diversity by having not just leukocytes but B cells,T cells,natural killer cells,antibodies.The components don't really matter.The point is that together,this diversity of different approaches can cope with more or less anything that evolution has been able to throw up.And the design is completely modular.You have the surface barrier of the human skin,you have the very rapidly reacting innate immune system and then you have the highly targeted adaptive immune system.The point is,that if one system fails,another can take over,creating a virtually foolproof system. 1:54I can see I'm losing you,Bob,but stay with me,because here is the really killer feature.The product is completely adaptive.It's able to actually develop targeted antibodies to threats that it's never even met before.It actually also does this with incredible prudence,detecting and reacting to every tiny threat,and furthermore, remembering every previous threat,in case they are ever encountered again.What I'm pitching you today is actually not a stand-alone product.The product is embedded in the larger system of the human body,and it works in complete harmony with that system,to create this unprecedented level of biological protection.So Bob,just tell me honestly,what do you think of my product? 2:47And Bob may say something like,I sincerely appreciate the effort and passion that have gone into your presentation,blah blah blah-- 2:56(Laughter) 2:58But honestly,it's total nonsense.You seem to be saying that the key selling points of your product are that it is inefficient and complex.Didn't they teach you 80-20?And furthermore,you're saying that this product is siloed.It overreacts, makes things up as it goes along and is actually designed for somebody else's benefit. I'm sorry to break it to you,but I don't think this one is a winner.
关于工作的优秀英语演讲稿 Different people have various ambitions. Some want to be engineers or doctors in the future. Some want to be scientists or businessmen. Still some wish to be teachers or lawers when they grow up in the days to come. Unlike other people, I prefer to be a farmer. However, it is not easy to be a farmer for Iwill be looked upon by others. Anyway,what I am trying to do is to make great contributions to agriculture. It is well known that farming is the basic of the country. Above all, farming is not only a challenge but also a good opportunity for the young. We can also make a big profit by growing vegetables and food in a scientific way. Besides we can apply what we have learned in school to farming. Thus our countryside will become more and more properous. I believe that any man with knowledge can do whatever they can so long as this job can meet his or her interest. All the working position can provide him with a good chance to become a talent. 1 ————来源网络整理，仅供供参考
1、统计学 统计学是一门阐明如何去采集、整理、显示、描述、分析数据和由数据得出结论的一系列概念、原理、原则、方法和技术的科学，是一门独立的、实用性很强的通用方法论科学。 2、指标和标志 标志是说明总体单位属性或特征的名称。指标是说明总体综合数量特征和数量关系的数字资料。 3、总体、样本和单位 统计总体是统计所要研究的对象的全体，它是由客观存在的、具有某种共同性质的许多个体所构成的整体。简称总体。构成总体的个体则称为总体单位，简称单位。样本是从总体中抽取的一部分单位。 4、统计调查 统计调查是根据统计研究的目的和要求、采用科学的方法，有组织有计划的搜集统计资料的工作过程。它是取得统计数据的重要手段。 5、统计绝对数和统计相对数 反映总体规模的绝对数量值，在社会经济统计中称为总量指标。统计相对数是两个有联系的指标数值之比，用以反映现象间的联系和对比关系。 6、时期指标和时点指标 时期指标是反映总体在一段时期内累计总量的数字资料，是流量。时点指标是反映总体在某一时刻上具有的总量的数字资料，是存量。 7、抽样估计和假设检验 抽样估计是指根据所抽取的样本特征来估计总体特征的统计方法。假设检验是先对总体的某一数据提出假设，然后抽取样本，运用样本数据来检验假设成立与否。 8、变量和变异 标志的具体表现和指标的具体数值会有差别，这种差别就称为变异。数量标志和指标在统计中称为变量。 9、参数和统计量 参数是反映总体特征的一些变量，包括总体平均数、总体方差、总体标准差等。统计量是反映样本特征的一些变量，包括样本平均数、样本方差、样本标准差等。 10、抽样平均误差 样本平均数与总体平均数之间的平均离散程度称之为抽样平均误差，简称为抽样误差。重复抽样的抽样平均误差为总体标准差的1/n。 11、抽样极限误差 抽样极限误差是指样本统计量和总体参数之间抽样误差的可能范围。我们用样本统计量变动的上限或下限与总体参数的绝对值表示抽样误差的可能范围，称为极限误差或允许误差。 12、重复抽样和不重复抽样 重复抽样也称为回置抽样，是从总体中随机抽取一个样本时，每次抽取一个样本单位时都放回的抽样方式。不重复抽样也叫不回置抽样，它是在每次抽取样本单位时都不放回的抽样方式。13、点估计和区间估计 点估计也叫定值估计，就是直接用抽样平均数代替总体平均数，用抽样成数代替总体成数。区间估计是在一定概率保证下，用样本统计量和抽样平均误差去推断总体参数的可能范围的估计方法。 14、统计指数 广义上来说，它是表明社会经济现象的数量对比关系的相对指标。狭义上来说，它是反映不能直接相加对比的复杂总体综合变动的动态相对数。 15、综合法总指数 凡是一个总量指标可以分解为两个或两个以上的因素指标时，将其中一个或一个以上的因素指
个人先进事迹简介 01 在思想政治方面,xxxx同学积极向上,热爱祖国、热爱中国共产党,拥护中国共产党的领导.利用课余时间和党课机会认真学习政治理论,积极向党组织靠拢. 在学习上,xxxx同学认为只有把学习成绩确实提高才能为将来的实践打下扎实的基础,成为社会有用人才.学习努力、成绩优良. 在生活中,善于与人沟通,乐观向上,乐于助人.有健全的人格意识和良好的心理素质和从容、坦诚、乐观、快乐的生活态度,乐于帮助身边的同学,受到师生的好评. 02 xxx同学认真学习政治理论,积极上进,在校期间获得原院级三好生,和校级三好生,优秀团员称号,并获得三等奖学金. 在学习上遇到不理解的地方也常常向老师请教,还勇于向老师提出质疑.在完成自己学业的同时,能主动帮助其他同学解决学习上的难题,和其他同学共同探讨,共同进步. 在社会实践方面,xxxx同学参与了中国儿童文学精品“悦”读书系,插画绘制工作,xxxx同学在班中担任宣传委员,工作积极主动,认真负责,有较强的组织能力.能够在老师、班主任的指导下独立完成学院、班级布置的各项工作. 03 xxx同学在政治思想方面积极进取,严格要求自己.在学习方面刻苦努力,不断钻研,学习成绩优异,连续两年荣获国家励志奖学金；作
为一名学生干部,她总是充满激情的迎接并完成各项工作,荣获优秀团干部称号.在社会实践和志愿者活动中起到模范带头作用. 04 xxxx同学在思想方面,积极要求进步,为人诚实,尊敬师长.严格 要求自己.在大一期间就积极参加了党课初、高级班的学习,拥护中国共产党的领导,并积极向党组织靠拢. 在工作上,作为班中的学习委员,对待工作兢兢业业、尽职尽责 的完成班集体的各项工作任务.并在班级和系里能够起骨干带头作用.热心为同学服务,工作责任心强. 在学习上,学习目的明确、态度端正、刻苦努力,连续两学年在 班级的综合测评排名中获得第1.并荣获院级二等奖学金、三好生、优秀班干部、优秀团员等奖项. 在社会实践方面,积极参加学校和班级组织的各项政治活动,并 在志愿者活动中起到模范带头作用.积极锻炼身体.能够处理好学习与工作的关系,乐于助人,团结班中每一位同学,谦虚好学,受到师生的好评. 05 在思想方面,xxxx同学积极向上,热爱祖国、热爱中国共产党,拥护中国共产党的领导.作为一名共产党员时刻起到积极的带头作用,利用课余时间和党课机会认真学习政治理论. 在工作上,作为班中的团支部书记,xxxx同学积极策划组织各类 团活动,具有良好的组织能力. 在学习上,xxxx同学学习努力、成绩优良、并热心帮助在学习上有困难的同学,连续两年获得二等奖学金. 在生活中,善于与人沟通,乐观向上,乐于助人.有健全的人格意 识和良好的心理素质.
尊敬的领导，老师，亲爱的同学们， 大家好！我是5班的梁浩东。今天早上我坐车来学校的路上，我仔细观察了路上形形色色的人，有开着小车衣着精致的叔叔阿姨，有市场带着倦容的卖各种早点的阿姨，还有偶尔穿梭于人群中衣衫褴褛的乞丐。于是我问自己，十几年后我会成为怎样的自己，想成为社会成功人士还是碌碌无为的人呢，答案肯定是前者。那么十几年后我怎样才能如愿以偿呢，成为一个受人尊重，有价值的人呢？正如我今天演讲的题目是：自主管理。 大家都知道爱玩是我们孩子的天性，学习也是我们的责任和义务。要怎样处理好这些矛盾，提高自主管理呢？ 首先，我们要有小主人翁思想，自己做自己的主人，要认识到我们学习，生活这一切都是我们自己走自己的人生路，并不是为了报答父母，更不是为了敷衍老师。 我认为自主管理又可以理解为自我管理，在学习和生活中无处不在，比如通过老师，小组长来管理约束行为和同学们对自身行为的管理都属于自我管理。比如我们到一个旅游景点，看到一块大石头，有的同学特别兴奋，会想在上面刻上：某某某到此一游话。这时你就需要自我管理，你需要提醒自己，这样做会破坏景点，而且是一种素质低下的表现。你设想一下，如果别人家小孩去你家墙上乱涂乱画，你是何种感受。同样我们把自主管理放到学习上，在我们想偷懒，想逃避，想放弃的时候，我们可以通过自主管理来避免这些，通过他人或者自己的力量来完成。例如我会制定作息时间计划表，里面包括学习，运动，玩耍等内容的完成时间。那些学校学习尖子，他们学习好是智商高于我们吗，其实不然，在我所了解的哪些优秀的学霸传授经验里，就提到要能够自我管理，规范好学习时间的分分秒秒，只有辛勤的付出，才能取得优异成绩。 在现实生活中，无数成功人士告诉我们自主管理的重要性。十几年后我想成为一位优秀的，为国家多做贡献的人。亲爱的同学们，你们们？让我们从现在开始重视和执行自主管理，十几年后成为那个你想成为的人。 谢谢大家！
关于工作的英语演讲稿 【篇一：关于工作的英语演讲稿】 关于工作的英语演讲稿 different people have various ambitions. some want to be engineers or doctors in the future. some want to be scientists or businessmen. still some wish to be teachers or lawers when they grow up in the days to come. unlike other people, i prefer to be a farmer. however, it is not easy to be a farmer for iwill be looked upon by others. anyway,what i am trying to do is to make great contributions to agriculture. it is well known that farming is the basic of the country. above all, farming is not only a challenge but also a good opportunity for the young. we can also make a big profit by growing vegetables and food in a scientific way. besides we can apply what we have learned in school to farming. thus our countryside will become more and more properous. i believe that any man with knowledge can do whatever they can so long as this job can meet his or her interest. all the working position can provide him with a good chance to become a talent. 【篇二：关于责任感的英语演讲稿】 im grateful that ive been given this opportunity to stand here as a spokesman. facing all of you on the stage, i have the exciting feeling of participating in this speech competition. the topic today is what we cannot afford to lose. if you ask me this question, i must tell you that i think the answer is a word---- responsibility. in my elementary years, there was a little girl in the class who worked very hard, however she could never do satisfactorily in her lessons. the teacher asked me to help her, and it was obvious that she expected a lot from me. but as a young boy, i was so restless and thoughtless, i always tried to get more time to play and enjoy myself. so she was always slighted over by me. one day before the final exam, she came up to me and said, could you please explain this to me? i can not understand it. i