IGR J19140+0951

Other name = IGR J19140+098 (IAUC 8088), EXO 1912+097

Spin P. (s)
Companion Radio Counterpart Infrared/Optical Counterpart
R.A. (J2000) Dec. (J2000) References (position) R.A. (J2000) Dec. (J2000) References (position)
High Mass X-ray Binary

Probable neutron star P~5880s
B0.5 Ia/ d= 3.6kpc 2MASS J19140422+0952577 in't Zand et al. 2005
19h 14m 4.231s 9o 52' 58.35"
Published Papers
Miscellaneous :

Swank & Markwardt 2003 Atel 128 :
  • NH=~6 x 1022 cm-2
  • Fe Line eq. width 550 eV in RXTE/PCA
Corbet et al. 2004 Atel 269:
  • Sinusoidal modulation of the RXTE/ASM flux with a period of 13.55 days
  • Activity detected with RXTE/ASM as early as 1996
Hannikainen et al. 2004 A&A, 423, L17:
  • (At least) Two Spectral states: one with thermal component and power law tail, one characteristic of thermal Comptonisation
  • INTEGRAL/ISGRI image of the field available here
Rodriguez et al. 2005 A&A, 432, 235:
  • Spends most of its time in a faint luminosity state characteristic of thermal Comptonisation
  • Variations of NH up to ~1023 cm-2
  • Iron line of variable intensity
in't Zand et al. 2006 A&A:
  • Flux lower than any INTEGRAL obs. but twice as high as all RXTE from Rodriguez et al. 2005
  • Ks~8.7, I~13.0, V> 18.8
  • Possible pulsation at 6.5 ks, but need confirmation
Wen et al. 2006 :
    Pulsation from RXTE/ASM confirmed at P=13.552d
Rodriguez al. 2006 (ATel 800):
  • RXTE/PCA and Swift/XRT => faintest state ever observed
  • 1-20 flux is 1.54 x10-11 erg/s/cm2(Swift normalization),
  • 1-20 keV unabsorbed flux is 2.47 x10-11 erg/s/cm2
  • amplitude of X-ray flux variations of at least a factor 150 between different observations
  • Another member of class of heavily absorbed sources
Nespoli et al. 2007 (ATel 983):
  • HeI and NIII/CIII in emission (weak for the later)
  • HeI and Br-gamma in absorption
  • absence of HeII
  • B1 supergiant
Hannikainen et al. 2007 MNRAS:
  • K- and H-band spectra analyzed
  • Spectral lines HeI (2.0581 and 2.1126 microns), NIII (2.1155 microns) and HI (Br-gamma at 2.1661 microns) for the K-band spectrum, and the HeI line (1.7002 microns) for the H-band spectrum.
  • Confirm the supergiant nature of the star, tweak the spectral classification to B0.5.
  • Distance of 5 kpc is estimated. A B0.5 supergiant
  • Supports the Sagittarius arm location
Chaty et al. 2008:
  • Near infrared observations
  • J=11.32, H=9.73, Ks=8.84
  • IR spectra dominated by Paschen and Brackett H, HeI and He II emission lines
  • NIR spectra typical of O/B star, and lines of supergiant.
Rahoui et al. 2008:
  • Medium infrared observations and GLIMPSE data
  • MSX object given by in't Zand is a blnd of sources
  • SED fitting => AV=16.5, T*=22500 K
  • No need for additional component to fit spectra
  • Suggested distance 3.1 kpc
Nespoli et al. 2008:
  • Infrared spectroscopy
  • B0.5 Iab
  • Distance 1.1 (-0.8 +2.3) kpc
  • Local absorption comes from material concentrated around the compact object
Prat et al. 2008:
  • Spectral analysis of34 simultaneous RXTE and INTEGRAL observations
  • Fits with absorbed power law, plus high energy cut off when required, and absorbed comptonization model
  • Spectral parameters => system very likely hosts a neutron starE
  • Evolution of NH strongly correlated with the orbit of the system => compact object deeply embedded in the wind of the companion
  • Wind mass-loss rate of ~5 E-8 solar masses/year and orbital inclination ~ 38-75 degrees.
  • Soft excess in 4 observations, at orbital phases consistent with the neutron star being behind the companion => interpreted as reprocessing of the X-ray emission originating from the neutron star by the surrounding ionised gas
Torrejón et al. 2009:
  • Optical spectroscopy
  • Companion is a Sg B0.5 Ia star
  • distance 3.6 kpc
  • Typical Sg-HMXB
Sidoli et al. 2016 (MNRAS):
  • Discovery of 1.46 mHz QPO (and higher harmonics) during an XMM-Newton observation
  • Re-analysis of a Chandra archival observation => modulation at 0.17+/-0.05mHz, very likely NS spin period (although a QPO cannot be excluded)
  • Faintest X-ray state observed (2e-12 erg/cm2/s, 2-10 keV, XMM data)
  • Duty cycle (INTEGRAL archive) => system intermediate between persistent supergiant HMXBs and SFXTs.

Last updated 13 June 2016

Jerome Rodriguez