| Miscellaneous :
| Capitanio et al. 2006 (ApJ):
- confirm the low absorption (Nh<1e22cm-2)
- Comptonised spectrum,
- second epoch shows the presence of bright thermal component in soft X-rays.
- transition form a hard state to a soft state.
- 3rd epoch => spectra can be fitted with a Comptonised model: transition back
to the hard state.
- Hysteresis in transitions
| Bazzano et al. 2006 (ApJ):
- 11.6+/-0.6 mCrab in 100-150 keV.
| Kennea & Capitanio 2007
- Swift observations => absorbed disk blackbody, with
NH=0.51e22 cm-2, and kT = 2.1 keV.
- 0.2-10 keV unabsorbed flux from the source ~1e-10erg/s/cm2
- power law yields a good fit, with parameters similar to those
observed in the past during a hard state.
- 0.2-10 keV unabsorbed flux ~9 E-10 erg/s/cm2
- Not associated with tentative radio counterpart of Rupen et al., Pandey et al.
| Chaty et al. 2008:
- Infrared observations
- 2MASS source formerly suggested to be counterpart is
outside Swift error box. Source is NOT the F8 V star.
- 2 candidates in NIR images, favour 1 as the counterpart
- J=16.73, H=15.83, Ks=15.36
- Rstar/Dstar very low => maximum radius
- SED fitting => Av=6.8, T=6900 K
- Not a Giant, nor a superGiant
- Probable LMXB in Gal. Bulge
| Capitanio et al. 2008:
- Quiescence with upper limit on the luminosity of L< 7e32 erg/s => source most probably hosts a black hole.
- Begining of a new outburst seen with Swift.
- Refute the previously suggested radio counterpart for this source.
- Re analysis of VLA data => new radio counterpart at a position
consistent with that of the Swift source.
- Radio spectrum is inverted (ie self absorbed): typical of the hard
states of black hole.
- Swift spectrum: hard spectral state
- Source then softens, black body component needed in fits
| Krimm et al. 2011; Krimm & Kennea 2011 ATel 3144 and ATel 3148:
- Renewed activity seen with Swift/BAT
- Swift observation => No flux from IGR J17098-3628
- IGR J17091-3624 is strongly detected in the XRT image
- Spectrum: absorbed power law NH = 1.10 x 1022 cm-2 and Γ= 1.73
- The source is not detected by UVOT
| Torres et al. 2011 ATel 3150:
- Detection of the optical and near-infrared counterparts
- I = 18.35 during outburst while in the 2005 images I = 20.32
- Detection of a Ks=16.65 source consistent with the
- Finding chart here
(courtesy M.A.P. Torres)
| Corbel et al. 2011 ATel 3167:
- ATCA observation => presence of a single radio source within the X-ray error circle consistent with the optical counterpart
- Flux densities of ~1.3 mJy at 5.5 and 9 GHz => consistent with flat radio
spectrum, usually associated self absorbed compact jets
- Swift XRT spectra closest to the radio observation: 2011-02-09
NH = 0.72 x 1022 cm-2, Γ = 1.41
NH = 0.74 x 1022 cm-2, Γ = 1.52
- Parameters + inferred luminosity (at 8 kpc) => in the radio/X-ray correlation diagram between the standard track and the track possibly indicative
of a radiatively efficient black hole in the hard state
| Rodriguez et al. 2011 ATel 3168:
- Timing analysis of 4 RXTE observations
- Data contaminated by GX 349+2, but manage to roughly correct its influence
- All PDS but the one from the first observation => ~0.1 Hz
QPO, with an increasing RMS amplitude (from 3.2% to 4.5%).
- Lend further credence to the fact that IGR J17091-3624 is a black hole binary in a hard state
| Shaposhnikov 2011 ATel 3179:
- Fast evolution of the QPO seen in this source: 0.1 Hz QPO
is observed at 0.34, 0.45 and 1.66 Hz in the three most recent observations (Feb 18,19
and 20, 2011)
- QPO harmonic also observed at ~3.3 Hz (last observation)
- Hardness is seen to decrease=> spectrum is getting softer
- Behavior consistent with transition to the soft state
| Del Santo et al. 2011 ATel 3203:
- Swift and INTEGRAL observations of Feb 28, 2011
- XRT data alone need a disc in the model fit
- Joint 0.8-200 keV XRT+IBIS/ISGRI spectrum <=> absorbed (disc +
powerlaw) with NH~1.00 x 1022 cm-2,
kTdisc~1.0 keV and Γ~2.2
- No high-energy cut-off requested up to 200 keV
- Presently in the
canonical high/soft spectral state of BHCs
| Altamirano et al. 2011 ATel 3225:
- Discovery of a ~10 mHz QPO most likely from IGR J17091-3624
- QPO is only intermittently visible with an average 2-60 keV fractional rms amplitude of 5.3%
- Fractional rms amplitude increases from ~3.5% below 5 keV to a
maximum of ~10% in the 15-30 keV range
- 2 QPOs at 2.3 Hz and 8.0Hz, with fractional rms
amplitudes of 10.9% and 6.7%, are found in the same obs.
| Kuulkers et al. 2011 ATel 3229:
- INTEGRAL => IGR J17098-3628 is not active, while J17091-3624 is
- mHz QPO is from IGR J17091-3624
| Altamirano et al. 2011 ATel 3230:
- mHz QPOs have increased in frequency by a factor of ~3
- PCA light curve displays flaring events occurring at a rate of 25-30 mHz. Wide diversity in the flare profiles
- Flares are also observed with Swift/XRT (IGR J17098-3628 not detected by Swift)
- Reminiscent (while of lower flux) of the "heartbeat" oscillations seen in the black hole candidate GRS 1915+105.
| Pahari et al. 2011 ATel 3266:
- Multiple peaks with evolving frequencies in RXTE observations
- Comparison to the class rho of
| Altamirano et al. 2011 ATel 3299:
- Heartbeat oscillations observed in all (but 3) observations performed since March 19th 2011
- Frequency of the (heartbeat) oscillations increased with time (up to ~100 mHz 2011/04/18)
- Also associated with a loss of regularity.
- On 04/19: broad variety of complex behavior similar to the class "beta" of GRS 1915+105 (different timescale)
- QPO at 5-8 Hz occurring only during low intensity periods are also present in this obs.
| Pahari et al. 2011 ATel 3418:
- In rho-type oscillations both small and large amplitude oscillations are
- Intervals of large bursts and short bursts appearing alternatively
- Characteristic time scale is ~40.25 sec
- Peak-to-dip count rate ratio ~3-5 for large bursts ; 1.5-2 for short bursts
- From 26 May 2011 to 03 June 2011 # of large burst intervals and their
maximum peaks seen to decrease=>disappeared on 04 Jun 2011.
| Rodriguez et al. 2011 A&A:
- 1st four simultaneous
multi-wavelength observations (ATCAn Swift, INTEGRAL, RXTE) of this source, during the 2011 outburst
- Hard shard state in the first 2 observations, soft intermediate state later
- Luminosity at the state transition => distance to the source of ~11 to ~17 kpc
(assuming BH mass of 10 Msun).
- The radio vs X-ray luminosity properties similar to other black hole binaries if
distance greater than 11 kpc
- Radio => Preferred distance of 17 kpc.
- Observed radio-X-ray behaviour more typical to that of GX 339-4 or H1743-322
than that of GRS 1915+105
| Pahari et al. 2011 ATel 3667:
- RXTE light curves: dips lasting 20-30s similar to GRS 1915+105 in ω and θ classes
- Peak in hard color coincident with an intensity dip, instead of usual (in BHB) accompanying dip in hard color
| Altamirano et al. 2011 (ApJ):
- Detailed analysis of the 2011 RXTE observations
- Identify 7 patterns of variability in light curves, similar to classes seen in GRS 1915+105
- Typical timescales of variability & brightness respectively shorter and fainter compared to 1915+105
- Either models based on Eddington Luminosity fail for IGR J17091-3624, or distance well above 20 kpc, or
harbours a very light black holes
| King et al. 2012 (ApJ):
- Observations with Chandra
- High resolution spectra =>presence of absorption line attributed to a fast
disk wind component
- Simultaneous EVLA observation => jet activity quenched during Chandra observations
- Presence of a disk wind when in soft state compatible with what observed in other such sources
| Altamirano et al. 2012 (ApJ):
- Discovery of a high frequency QPO
- Frequency = 64.8 Hz very similar to the 67 HZ QPO of GRS 1915+105
- Potential feature at 164 Hz, strengthening the similarity
to the 1915's HFQPOs
- Implication of these findings are discussed in the view of the potential
high distance, or low mass BH in the IGR source
| Rebusco et al. 2012 (A&A):
- HFQPO due to non-linear resonances of oscillating
modes in the disc, in 5:2 ratio => BH mass ~ 6 Msun (comparison with 1915+105)
| Pahari et al. 2012 (MNRAS):
- Analysis of RXTE data of the 2011 outburst
- Identification and comprehensive characterisation of 2 variability classes never seen
in any other black hole binaries, including GRS 1915+105
| Capitanio et al. 2012 (MNRAS):
- analysis of the long term Swift and INTEGRAL monitoring
- Up to the transition to the soft state => HID and rms-intensity diagram show similar pattern to other sources
- After behaviour more similar to that of GRS 1915+105
- Spectral analysis of the data => heartbeat pattern corresponds to rapid emptying and refiling of the inner
region of an accretion disc.
- In addition to being at a large distance, the
source may also have a large inclination, which would explain its faintness.
| Bodaghee et al. 2012 (ApJ):
- Chandra observation => refined X-ray position
- Source position compatible with all previously suggested counterparts => securing source as a μquasar
| Wijnands et al. 2012 (MNRAS):
- Re-analysis of 2 XMM observations during quiescence
- Contrary to what previously claimed source detected at 0.5-10 keV fluxes of
9 and 12 e-14erg/cm2/s.
- In both observations Γ~1.6 (absorption fixed).
- Assuming relation between quiescent luminosity and orbital period holds =>
orbital period between >4 d (at 10 kpc) and tens of days in case of a larger distance
| Rao & Vadawale 2012 (ApJ):
- Analysis of simultaneous RXTE and XMM observations
- Phase resolved spectroscopy of the ρ-like type of variability
- Comparison to GRS 1915+105 and investigation of differences
- Source is a high inclination system (> 53deg)
- Low luminosity explained only if the spin of the BH has a low (or even negative) value, in a distant
and light (<5 Msun) BH
| Reis et al. ATel 4382:
- XMM spectral analysis => presence of a number
of absorption lines and a distinct feature at 7.1 keV
- Photoionization model provides a good fit, but a relativistic iron line model
provides a better modeling
- System probably in a soft intermediate state during this obs
- Disk temperature ~1.1 keV and a power law Γ~1.9
- Analysis of the broadened iron line => inclination to
the disc < 62°ree; with emissivity index Q<7.4
- Inner radius is constrained to be <2.3GM/c2 =>
black hole with a spin a*>~0.9 (in contradiction with Rao & Vadawale)
| Pahari et al. 2013, 2014 (ApJ & MNRAS):
- Spectral and timing studies of the RXTE observations with cycles and in depth comparison with GRS 1915+105
- The properties of hard X-ray dips of 17091 consistent with those of 1915's abrupt transitions
- Correlation between X-ray cycle time and time spent in hard dip in the two sources
- Difference between hard dips and peak spectra due to variation of the (p-free) accretion disk
- Oscillations due to limit cycle beaviour of unstable radiation pressure dominated inner disk
| Janiuk et al. (2015) (A&A):
- Heartbeat oscillations => radiation pressure instability of accretion disk
- Disc outflow (wind) => plausible mechanism to regulate (and stop) oscillations
- Wind properties (Chandra) => 2 wind components with rates ~2.7 e17 g/s and 4.2e17 g/s
- Launching sites => between 380 and 4700-5900 RG and 950 and 4200-4900RG
- Modeling gives parameter (outflow rates) compatible with observations
- Geometry of disc-corona-wind presented
| Iyer et al. (2015) (ApJ):
- Spectro-temporal study of RXTE and Swift data
- 3 different methods => 8.7 MSun < MBH < 15.6 MSun @ 90% confidence