IGR J05414-6858 detected in X-ray outburst with SWIFT
ATel #3537; R. Sturm, F. Haberl, W. Pietsch (Max-Planck-Institut fuer extraterrestrische Physik), S. Immler (NASA/CRESST/GSFC)
on 9 Aug 2011; 15:02 UT
Credential Certification: Richard Sturm (firstname.lastname@example.org)
Subjects: X-ray, Binary, Neutron Star, Transient
We report the re-detection of IGR J05414-6858 in the Large Magellanic Cloud (LMC) with SWIFT during the SWIFT LMC survey (PI Immler) observation 7 from 2011 Aug. 5, 15:28 to Aug. 6, 22:27 UT.
IGR J05414-6858 was discovered with INTEGRAL on 2010 Jun. 6-14 (ATEL #2695).
In a Swift follow-up observation on 2010 Jun. 25, the source was detected (ATEL #2696)
and identified as Be-X-ray Binary (ATEL #2704). An additional Swift observation was performed on 2011 Jun. 30.
To model the X-ray spectra we used a power-law model with photoelectric absorption.
The Galactic column density was fixed to 6x1020 cm-2 with solar abundances.
An additional source intrinsic and/or LMC column density with abundances set to 0.5 solar for elements heavier than helium was a free parameter in the fit.
A joint fit to the spectra of all three SWIFT observations results in a LMC column density of (2.3 ± 1.7)x1021 cm-2 and
a photon index of 0.83 ± 0.17.
Net counts, detected fluxes and unabsorbed luminosities for a LMC distance of 50 kpc in the (0.2-10.0) keV band are given in the following table:
Date Exp [s] Cts Flux [10-12 erg cm-2 s-1] L [1036 erg s-1]
2010 Jun. 25 3920 221 5.844 (5.69 - 5.79) 1.85
2010 Jun. 30 5202 540 10.076 (9.89 - 10.05) 3.19
2011 Aug. 5 3349 40 3.210 (3.01 - 3.06) 1.02
In 2010 the outburst has lasted for more than 20 days, suggesting a type II outburst of the Be system.
Further monitoring of the 2011 outburst will help to decide if the source is undergoing another type II outburst.