IGR J19294+1816

Other name = Swift J19298+1821

Type Orb./Pulse periods Radio Counterpart Infrared/Optical Counterpart
R.A. (J2000) Dec. (J2000) References R.A. (J2000) Dec. (J2000) References
HMXB / X-ray Pulsar
Be system or SFXT ?
117 d / 12.43781 s 2MASS J19295591+1818382 Rodriguez et al. 2009 ATel 1998
Published Papers
Miscellaneous :

Tuerler et al. 2009 ATel 1997:
  • 20-40 keV flux of ~14 +/- 2 mCrab, not detected at higher energies
  • Averaged spectrum of the source is consistent with a single powerlaw in Γ= 4.0=>20-40 keV flux =1.1 E-10 erg/cm^2/s.
  • Do not exclude an association with 2E 1927.5+1805
Rodriguez et al. 2009 ATel 1998:
  • Analyses of Swift archival observations performed on 2007 december 9 and 13.
  • Source = Swift 1929.8+1821 at position inconsistent with that of the 2E 1927.5+1805
  • 2MASS J19295591+1818382 is counterpart with infrared magnitudes J=14.56 ±0.03, H=12.99 ±0.02 and Ks=12.11±0.02.
  • Swift spectrum is well fitted with an absorbed power law, or an absorbed black body
  • NH=3.7x1022 cm-2, Γ=0.8, F2-10 keV, unabs=3.6e-11 erg/s/cm-2 (power law)
  • kTbb=2.1 keV F2-10 keV, unabs.=3.0e-11 erg/s/cm2 (BBody), with size RBB=(0.46 * D10 kpc) km (D10 kpc distance to the source in units of 10 kpc)
  • Feature at 8.0e-2Hz in the power spectrum, could be a coherent pulsation although nothing seen in folded light curve
  • IGR J19294+1816 is more likely associated to Swift J1929.8+1821
  • Possible X-ray binary possibly containing a pulsar
Krimm et al. 2009 ATel 1999:
  • Detection in Swift/BAT archival observations
  • Earliest detection reported: January 13, 2006, 6 additional detections since then
  • Recent increased activity seen on March 23, 2009 (NOT 2008 as reported in the ATel), after March 28 the source has faded below detectability.
  • Possible sort of periodicity in the system at a period of ~56 days as seen from the period of detections with the BAT.
Strohmayer et al. 2009 ATel 2002:
  • RXTE Observation show pulsation at 12.44s and harmonics
  • Amplitude of pulse 37%
  • Highly variable phase average flux, possible quasi period of 190 s
  • Confirms the object is a possible pulsar
Corbet and Krimm 2009 ATel 2008:
  • Analysis of the Swift/BAT light curve covering the period Jan 1st 2006 to April 2 2009
  • Strong peak in the powe spectrum of the source at a period of 117 days<=> associate with the orbital period of the source
  • Occurrences of high flux at half this period=>interaction of the neutron star with the disk of the donor star.
  • Ephemeris: Tpeak (MJD) = 54,680.3 (+/- 0.6) + n x 117.2 (+/- 0.2)
  • Region of Be systems in the Corbet Diagram, compatible with the transient nature of this system.
Rodriguez et al. 2009 A&A:
  • Multi-instrumental (Swift, INTEGRAL, RXTE) analysis
  • 2MASS J19295591+1818382 has J=14.56, H=12.99 and Ks=12.11.
  • Swift and RXTE spectral analysis => rather hard source / evidence for local absorption in one observation
  • Timing study => barycentred period of 12.43781 s <=> spin period of a pulsar binary
  • Results compatible with a Be-HMXB but INTEGRAL => occurrences of short and intense flares reminiscent of SFXT ie system with a supergiant companion.
  • Definitive conclusion on the nature Be vs Sg not possible
Bozzo et al. 2010 ATel 2983:
  • ISGRI detection of a new outburst
  • Spectrum can be fit with a blackbody at a temperature of 4.8 keV.
Jenke et al. 2010 ATel 2985:
  • Fermi-GBM. The barycenter-corrected pulse frequency is 80.3111(4) mHz for data corresponding to 27-29 October, 2010
Bozzo et al. 2011 A&A :
  • INTEGRAL and Swift observations during 2010 outburst
  • Source flux decayed smoothly over a period of 2 months without spectral changes
  • Pulsations at 12.5s up to 50 keV
  • Marginal detection of the ~116d period
  • Very probably a Be-HMXB rather than an SFXT
Finger et al. 2012 ATel 3917 :
  • Detection of pulsed flux with Fermi GBM
  • Pulsed flux ~15 mCrab in the 12-50 keV range
  • Pulsation has a barycentric frequency of 80.2754 mHz
Fiochi et al. 2012 ATel 4135 :
  • Renewed activity with INTEGRAL/IBIS on may 26 2012
  • 18-60 keV spectrum is well fitted by a power law model with Gamma~3.6
  • Detection consistent with the rise of a new outburst and compatible with the known orbital period of 117 days.
Sidoli et al. 2012 ATel 4136 :
  • Swift observations after renewed activity
  • XRT spectrum well described by absorbed power law model, with Γ~1.25 and NH~ 8 x 1022 cm-2
  • 2 keV absorbed (NH~ 4 x1022 cm-2) black body provides a good fit
  • Detection of X-ray pulsations at P=12.457 at a fraction of ~ 60%.

Last updated 2 July 2012

Jerome Rodriguez