IGR J16493-4348


Other name = (?)

Type Orb. Period /pulse Per. Radio Counterpart Infrared/Optical Counterpart
R.A. (J2000) Dec. (J2000) References R.A. (J2000) Dec. (J2000) References
Heavily absorbed X-ray Binary
HMXB
BO.5 Ib
6.782d / 1069 s 2MASS J16492695-4349090
SSTGLMC G341.3752+00.5829
Kuiper et al. 2005 Atel 654
Hill et al. 2008, MNRAS
Published Papers
Miscellaneous :

Grebenev et al. 2005 Atel 457:
  • Are PSR J1649-4349 and IGR J16493-4348 associated?
Markwardt et al. 2005 Atel 465:
  • RXTE spectra highly absorbed NH~1023 cm-2
  • Γ = 1.4
  • No line in spectral fits, no pulsations.
Kuiper et al. 2005 Atel 654:
  • J,H and Ks magnitudes of 14.59, 12.86 and 11.94 respectively from 2MASS
  • Ks=12.0 with NTT/Sofi => IR counterpart not extremely variable.
  • No optical counterpart seen => strong absorption; heavily absorbed XRB
Hill et al. (2008, NRAS):
  • Refined X-ray position => not PSR J1649-4349
  • Spitzer counterpart
  • M3.6μ=11.25, M4.5μ=11.01, M5.8μ=10.9, M8.0μ=10.86
  • Companion either close dwarf star, or far early star
  • Spectral and temporal analysis => XRB
  • More likely a HMXB, although LMXB not completely ruled out
Nespoli et al. (2008): ATel 1396
  • K-band spectroscopy of 2MASS J16492695-4349090
  • No metal lines detected.
  • Detection of He I both in emission and absorption, and Brγ in absorption.
  • Spectral type is B0.5 Ib.
  • System is a neutron star (sg)HMXB.
Morris et al. 2009:
  • Suzaku observations
  • The source is an heavily absorbed HMXB, with NH=26 x 1022 partially covering the source with cov fraction of 62%
  • Γ=2.37
Nespoli et al. 2010 : (A&A)
  • Details of observations that led them to classify the source as a B0.5-1 Ia-Ib object => IGR a supergiant HMXB.
  • Strong He I emission (at 20581 Angstrom) strong He I absorption (21126A) and strong Br_gamma (21661A) in absorption
  • Absorption on the line of sight ~ Nh~2.9 10^22 cm-2
  • Excess absorbing matter is local to the X-ray source
  • Range of distance to the source between 6 and 26 kpc.
Corbet et al. 2010 ATel 2599 :
  • Highly significant pulsation in RXTE/PCA 2-10 keV Swift/BAT light curves at a period ~6.8d.
  • Sine wave fits lead to:
    Tmax (BAT) = MJD 54 301.39 + n x 6.7906
    Tmax (PCA) = MJD 54,301.55 + n x 6.7851
  • Period typical of orbital period for an HMXB with a Sg companion.
  • Significant second pulse in both lcs at around 20.07-20.09 d. Discuss possible nature (other XRB in the field, superorbital modulation,..)
Cusumano et al. 2010 (MNRAS) :
  • Significant periodicity in Swift/BAT at 6.782 d.
  • Identification of an eclipse in the folded light curve at T(MJD)=54175.92 +- n*P
  • Semi-major orbital axis a~55 Rsun~ 2 Rstar with a maximum eccentricity 0.15.
Corbet et al. 2010 ATel 2766 :
  • Highly significant modulation at 1069±7 s
  • Amplitude of the modulation ~ 20%.
  • Value consistent with the range of periods seen in other sgHMXBs
D'Ai et al. 2011 A&A:
  • Swift and Suzaku observations
  • Spectral fits => presence of a large absorption feature
  • Feature has ~10 keV width and centroid E~30-33 keV; interpreted as a resonant cyclotron absorption feature.
  • Estimate a surface magnetic field of ~ 3.7 e12 G.

Last updated 3 August 2011

Jerome Rodriguez