Rea, Nanda, Jonker, Peter G., Nelemans, Gijs, Pons, José A., Kasliwal, Mansi M., Kulkarni, Shrinivas R., Wijnands, Rudy
The X-ray quiescence of Swift J195509.6+261406 (GRB 070610): an optical bursting X-ray binary?
The Astrophysical Journal Letters. 2011, 729(2): L21. doi:10.1088/2041-8205/729/2/L21
URI: http://hdl.handle.net/10045/33855
DOI: 10.1088/2041-8205/729/2/L21
ISSN: 2041-8205 (Print)
Abstract: 
We report on an ~63 ks Chandra observation of the X-ray transient Swift J195509.6+261406 discovered as the afterglow of what was first believed to be a long-duration gamma-ray burst (GRB 070610). The outburst of this source was characterized by unique optical flares on timescales of second or less, morphologically similar to the short X-ray bursts usually observed from magnetars. Our Chandra observation was performed ~2 years after the discovery of the optical and X-ray flaring activity of this source, catching it in its quiescent state. We derive stringent upper limits on the quiescent emission of Swift J195509.6+261406, which argues against the possibility of this object being a typical magnetar. Our limits show that the most viable interpretation on the nature of this peculiar bursting source is a binary system hosting a black hole or a neutron star with a low-mass companion star (<0.12 M ☉) and with an orbital period smaller than a few hours.
Keywords:Stars: magnetic field, X-rays: individual (SWIFT J195509.6+261406), X-rays: stars
IOP Publishing
info:eu-repo/semantics/article