IGR J16479-4514

	IGR J16479-4514


	Other name =

Type	Spectral Type / Orb. period Super Orb P.	Radio Counterpart			Infrared/Optical Counterpart
		R.A. (J2000)	Dec. (J2000)	References	R.A. (J2000)	Dec. (J2000)	References
HXMB/ candidate SFXT	O8.5 I /3.32 d 11.880				16h 48m 06.8	-45° 12' 08.0"	Kennea et al. 2005Atel 599
References		Sguera et al. 2005 A&A, 444,221 Lutovinov et al. 2005,A&A, 444, 821 Sguera et al. 2006 ApJ, 646, 452 Walter et al. 2006 A&A, 435, 133 Chaty et al. 2008, A&A, 484, 783 Rahoui et al. 2008, A&A, 484, 801 Nespoli et al. 2008, A&A, 486, 911 Sguera et al. 2008, A&A 487, 619 Sidoli et al. 2008, ApJ, 687, 1230 Romano et al. 2008, ApJL, 680, L137 Bozzo et al. 2008, MNRAS, 391, L108 Jain et al. 2009, MNRAS, 397, L11 Bozzo et al. 2009, A&A, 502, 21 Romano et al. 2009, MNRAS, 399, 2021 Ducci et al. 2010, MNRAS, 408, 1540 Ratti et al. 2010, MNRAS, 408, 1866 Romano et al. 2011 MNRAS, 410, 1825 Wang & Chang 2012 A&A, 547, A27 Sidoli et al. 2013 MNRAS, 429, 2763 Corbet et al. 2013, accepted in ApJ arXiV 1309.4119

Miscellaneous :

Kennea et al. 2005 (Atel 599):

N_H=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:

20-60 keV ~120 mCrab

Walter et al. 2006:

some soft excess and marginal K-alpha line (EW < 280 eV)
N_H = 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, K_s=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 => A_V=18.5, T_star=32800 K => O8.5I
No need for additional component in SED fitting
d=4.9 kpc

Romano et al. 2008 ATel 1435:

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 flare)
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 N_H=16x10²²cm-2 and Γ=2.5, or absorbed bremsstrahlung with N_H=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 N_H=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 N_H=7.7x10²²cm-2 or kT=1.6 keV and N_H=4.5x10²²cm-2
No variations of N_H 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: MNRAS

Long XMM observation triggered just after a bright flare observed with Swift
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 ATel 1920:

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 ATel 1929:

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 light curves
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 plateau.
Time of minimum flux is ~ MJD 55993 with F_max occurring approximately 0.25 in phase after this.
A=(F_max - F_{min_{)/(F_mean ~ 130%}}
Ratio P_superorb/P_orb~ 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%

Last updated 8 Nov. 2013

Jerome Rodriguez