X–ray binaries : X–ray binaries



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X–ray binaries :

  • X–ray binaries :

    • Degenerate primary ( NS , BH)
    • 1035 erg s-1 < Lx < 1039 erg s-1
    • Low Mass X-ray Binaries (LMXB)
    • High Mass X-ray Binaries (HMXB)


Young luminous massive stars

  • Young luminous massive stars

  • 2 types :

    • Supergiant X-ray binaries
    • Be/X-ray pulsar ( BeX )
  • Supergiant X-ray binaries



Be star + X-ray pulsar

      • Be star + X-ray pulsar
      • 2 discs : - Be equatorial disc
      • - NS accretion disc
  • 3 possible periods

      • Pulse period
      • Orbital period
      • Super-orbital period
      • (such as in A0538-66)


MMW / MSMC ~ 50

  • MMW / MSMC ~ 50

  • 65 known HMXB in our galaxy

  • Now, we know 47 HMXBs in SMC



    • Studying the temporal properties of SMC/LMC X-ray binaries
    • Why are these SMC HMXBs all neutron star systems? where are the BH equivalents?
    • Do any of these BeX have the same properties as BeX system A0538-66 which shows a 421 days superorbital periodicity? What is causing this ?
    • Do any of this large number of HMXBs show properties similar to the microquasar SS433 ?


Data used : long-term database.

  • Data used : long-term database.

    • MACHO [MAssive Compact Halo Objects]
    • ( Alcock et al., 1996)
      • 1.25 m telescope at Mount Stromlo Observatory, Australia
      • Data available : from 1992 June - 2000 January
    • OGLE [ Optical Gravitational Lensing Experiment]
    • ( Udalsky et al,. 1997)
      • 1.3 m Warsaw telescope
      • at Las Campanas observatory, Chile
      • Phase II : January 1997 - ~ Dec 2000
      • Phase III : June 2001 - until now


We combined the light curves from MACHO, OGLE II, and OGLEIII of all known BeX.

  • We combined the light curves from MACHO, OGLE II, and OGLEIII of all known BeX.

  • Macho data available from : http://wwwmacho.anu.edu.au/Data/MachoData.html

  • OGLE II data : http://ogle.astrouw.edu.pl/

  • OGLE III data : http://ogle.astrouw.edu.pl/ogle3/xrom/xrom.html

  • Run Starlink PERIOD (package) to study their temporal properties.



Porb : 16.65 days

  • Porb : 16.65 days

  • Super-orbital period : ~ 421 days

  • Formation and depletion of the Be equatorial disc













  • TBB ~ 20-50 eV

  • Lbol ~ 1037 - 1038 erg s-1

  • SSS system :

      • WD
      • Sub-giant companion
      • High accretion rate , > 10-7 Msun yrs-1
  • WD burns H steadily at its surface

  • Contraction model : (Southwell et al., 1996)

      • accretion rate drops Optical luminosity decreases
      • rise in Teff
      • increase in X-ray luminosity
  • CAL 83 : X-ray emission occurs only during optical low state

  • ( Grenier & Di Stefano, 2002)



X-ray data : ROSAT

  • X-ray data : ROSAT

  • Optical : MACHO ( blue )







Finding more sources showing similar behaviour to A0538-66 using OGLE III data.

  • Finding more sources showing similar behaviour to A0538-66 using OGLE III data.

  • Why the compact object of all of these HMXBs are neutron star?

  • More understanding on the Supersoft X-ray binary

  • Investigating the variability of all these Be/X-ray pulsar if any of these has a periodicity comparable to 162 days as seen in SS433.

  • Finding the next SS433-like (continuous and precessing jets[disc]) among those HMXB in SMC .

  • Publish the result



SS433 : first known X-ray binary that emits relativistic jet

  • SS433 : first known X-ray binary that emits relativistic jet

  • Only continuously emitting micro-quasar

  • Key feature :

  • inclination : 79o e < 0.05 (Margon & Anderson 1989)

  • Jet velocity : 0.26 d = 5.5 kpc (Blundell et al. 2004)

  • Porb = 13.08 days Pprec = 162.5 days (Abell & Margon,1979)

  • f



Some BeX sources shows similar behaviour to A0538-66.

  • Some BeX sources shows similar behaviour to A0538-66.

  • SSS CAL83 and RXJ0513.9-6951 show a variability in a timescale 450 days and 167.94 days respectively.

  • We still need more Ogle III data or other long term optical data for some sources.

  • Investigation of the next SS433-like among those large number of HMXB needs to be done



Grimm et al. ,2003, Astron. Astrophys. Vol. 3 , Suppl., 257–269

  • Grimm et al. ,2003, Astron. Astrophys. Vol. 3 , Suppl., 257–269

  • Coe et al., 2008, astro-ph 0809.2665v1

  • Gardiner L.T. & Noguchi M, 1996,MNRAS, 278,191

  • Alcock, C., Allsman, R.A., Alves, D. et al. 1996, MNRAS 280, L49

  • Alcock, C. et al. 2001, MNRAS 321, 678.

  • Udalski, A., Kubiak, M., & Szymanski, M. 1997, Acta Astron., 47, 319

  • Lomb, N. R. 1976, Ap&SS, 39, 447

  • Stellingwerf, R. F.1978, ApJ 224, 953S

  • Scargle, J. D. 1982, ApJ, 263,835

  • Greiner, J. and DiStefano, R. (2002), A&A 387, 944–54

  • Ciatti et al., 1981

  • Southwell, K.A., Livio, M., Charles, P.A., O’Donoghue, D. and Sutherland, W.J. (1996), ApJ 470, 1065–74






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