XMM-Newton observation of the Soft Gamma Ray Repeater SGR 1627-41 in a low luminosity state
Abstract
The sky region containing the soft gamma-ray repeater SGR 1627-41 has been observed three times with XMM-Newton in February and September 2004. SGR 1627-41 has been detected with an absorbed flux of ~9x10-14 erg cm-2 s-1 (2-10 keV). For a distance of 11 kpc, this corresponds to a luminosity of ~3x1033 erg s-1, the smallest ever observed for a Soft Gamma Repeater and possibly related to the long period of inactivity of this source. The observed flux is smaller than that seen with Chandra in 2001-2003, suggesting that the source was still fading and had not yet reached a steady quiescent level. The spectrum is equally well fit by a steep power law (photon index \~3.2) or by a blackbody with temperature kT~0.8 keV. We also report on the INTEGRAL transient IGR J16358-4726 that lies at ~10' from SGR 1627-41. It was detected only in September 2004 with a luminosity of ~4x1033 erg s-1 (for d=7 kpc), while in February 2004 it was at least a factor 10 fainter.
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