| Miscellaneous :
| Kennea et al. 2005 (Atel
- NH=6.4 ± 0.9 x 1022 cm-2
- Gamma =1.09 ± 0.25
- flaring activity
- Mv=20.4 ± 0.4
| Sguera et al. 2005 : |
- Fast transient
- Recurrent outburst
- Flares lasting 30 min
- 20-30 keV peak flux of 850 mCrabs on one occasion
- Possible type I X-ray burst => LMXB
| Sguera et al. 2006:
| Walter et al. 2006:
- some soft excess and marginal K-alpha line (EW < 280 eV)
- NH = 7.7(+-1.7)x1022 at/cm2
- IR counterpart (1.3 arcsec away) has a K-band magnitude of 9.8
- unabsorbed flux (2-100 keV) is 1.8x10-10 ergs/cm2/s
| Chaty et al. 2008:
- Near infrared observations
- 2 candidates, candidate suggested by Walter is favoured.
- J=13.06, H=10.92, Ks=9.79
- Very red Near IR spectrum with absorption and emission lines
- The H Brackett serie, HeI HeII and FeII in emission in NIR spectra
- NIR spectra typical of sg O/B
| Rahoui et al. 2008:
- Medium infrared observations
- SED fitting => AV=18.5, Tstar=32800 K => O8.5I
- No need for additional component in SED fitting
- d=4.9 kpc
| Romano et al. 2008
- New outburst with Swift/BAT, consisted of two flares, the second
stronger than the first.
- BAT spectra are powerlaw-like (1st flare) and exponentially cut powerlaw-like (2nd
- XRT lightcurve composed of several flares,
| Sguera et al. 2008:
- Study of 19 X-ray flares, 10 newly discovered.
- All flares are well fitted (in the ISGRI band) with either a power law
(Gamma=2.2-3) or a bremsstrahlung (kT=21-46 keV).
- Joint XRT/JEM-X/ISGRI spectrum =>absorbed power law with
NH=16x1022cm-2 and Γ=2.5, or
absorbed bremsstrahlung with NH=9x1022 and kT=19 keV.
- Spectral analysis of this quiescent state ISGRI+Swift/XRT spectrum
=>absorbed powerlaw or bremstrahlung fit the data equally well with
Γ=2.2 or kT=20 keV, with NH=9x1022 cm-2.
Assuming a distance of 4.9 kpc they deduce
an average 20-60 keV luminosity of 5e34 erg/s.
- IGR J16479-4514 a possible transition object
between other SFXTs and classical SGXBs.
| Sidoli et al. 2008:
- Spectral analysis of the "out-of outburst" Swift data
- Absorbed pl or bbody fits the data well
- Γ= 1.6 and NH=7.7x1022cm-2 or
kT=1.6 keV and NH=4.5x1022cm-2
- No variations of NH with outburst value
| Romano et al. 2008:
- 0.2-150 keV spectral analysis of 3 particular
intervals during the rise of this source's outburst
- Spectra well represented with standard models for pulsars X-ray binaries
- No evidence for variability of the absorption.
- Compact object in this source is probably a pulsar.
| Nespoli et al. 2008:
- Infrared spectroscopy
- O9.5 Iab suggested
- Distance 2.8 (-1.7 +4.9)kpc
- Local absorption comes from material concentrated around the compact object
| Bozzo et al. 2008:
- Long XMM observation triggered just after a bright flare observed
- Observation is divided in two parts, one having a count rate higher than
the other by a factor of ~50 => probably the tail of the bright burst
- X-ray spectroscopic analysis =>faint phase is probably due
to obscuration of the source of X-rays
- Favour an X-ray eclipse as the origin
- Presence of an extended (tens of arcsec) dust scattering halo.
| Romano et al. 2009
- Detection of a new outburst with Swift/BAT on January 29 2009
at 06:33:07 UT.
- All spectral parameters consistent with those of previous outburst seen
315 days before
| La Parola et al. 2009
- New bright flare with Swift=> part of the same outburst
that triggered Swift/BAT on January 29
- Swift/XRT light curve obtained from the monitoting of the source
shows a large variability, with the source being always detected =>still active since January 29.
- Bright flares spaced by a few days are part of the same
outburst : this could be the case also in other SFXTs.
| Jain et al. 2009:
- Strong modulation of the 18-50 keV BAT light curve at 3.32
day => orbital period of the system
- Period less evident in the ASM data, but still significant
once the light curve is folded
- Presence of a 0.6d eclipsing phase in the
- Eclipse is seen at the same phase with both Swift and RXTE
| Bozzo et al. 2009:
- Swift observations during outburst in 2009, january
and comparison to previous ones.
- Outbursts precede the eclipse
- Onset of the 2005, 2008 and
2009 outbursts (seen with Swift/BAT) occur respectively
at orbital phases 0.36, 0.3654 and 0.36 => interpret this
as an evidence that the outburst, although rare, are connected
to the orbital phase
| Romano et al. 2009:
- Results of Swift monitoring of the source
- Duty cycle 17%
- Confirm detection P=3.32 d with BAT
- Complete spectral analysis => spectra well fitted with either an
absorbed power law or an absorbed black body
| Ducci et al. 2010:
- Applcation to clumpy wind model=> parameters of the wind slightly different from that of other systems.
- Study possible other mechanism of flaring activity
- X-ray photoionisation can lead to formation of a transient accretion disc in this source (and other
short orbital period ones).
| Ratti et al. 2010:
- Chandra + optical observation of the counterpart
- NIR colour indicate a late type red giant or a supergiant earlier than O9 => counterpart peculiar in the NIR region
| Romano et al. 2011:
- 2 years of Swift monitoring
- duty cycle of inactivity ~ 19%
- X-ray spectroscopy in different luminosity phases of activity
| Wang & Chang 2012 (A&A):
- Mention of a 2.14s period (refering to http://hera.ph1.uni-koeln.de/~heintzma/Integral/SFXT.htm which worngly refer to Sguera et al.), but
no evidence for such a pulse has ever been found
- Study retrograde wind accretion scenario
- => spin and orbital period => R corrotation ~ 9.9e9 cm and source is a retrograde accretor
| Sidoli et al. 2013 (MNRAS):
- 80% of the orbit followed with Suzaku
- Variability of more than two orders of magnitude, with the begining of the observation made during the eclipse by the Sg companion
- No evidence for variability of the absorption column density (@ ~ 1023 cm-2)
- Wind density estimated to ρ~ 7x 10-14 g.cm-3
- Mechanism is to be invoked to reduce the mass accretion rate to be consistent with the luminosity observed
| Corbet et al. 2013 ATel 5126 (see also ApJ paper):
- SuperOrbital modulation found at a period 11.880 days in Swift/BAT data
- Light curve folded on this period <=> relatively sharp rise from minimum to maximum followed by a
- Time of minimum flux is ~ MJD 55993 with Fmax occurring approximately 0.25 in phase after this.
- A=(Fmax - Fmin)/(Fmean ~ 130%
- Ratio Psuperorb/Porb~ 3.6 similar to other wind accretion HXMB with superorbital periods
| Drave et al. 2013 ATel 5131:
- Confirmation of SuperOrbital modulation with INTEGRAL at 11.891 d
- Same profile for the folded light curve as that seen with Swift. A=160%