Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena
Scientific paper
2012-04-26
Astronomy and Astrophysics
Astrophysics
High Energy Astrophysical Phenomena
20 pages, 15 figures, submitted to A&A
Scientific paper
MAXI J1659-152 is a bright X-ray transient black-hole candidate binary system discovered in September 2010. We report here on MAXI, RXTE, Swift, and XMM-Newton observations during its 2010/2011 outburst. We find that during the first one and a half week of the outburst the X-ray light curves display drops in intensity at regular intervals, which we interpret as absorption dips. About three weeks into the outbursts, again drops in intensity are seen. These dips have, however, a spectral behaviour opposite to that of the absorption dips, and are related to fast spectral state changes (hence referred to as transition dips). The absorption dips recur with a period of 2.414+/-0.005 hrs, which we interpret as the orbital period of the system. This implies that MAXI J1659-152 is the shortest period black-hole candidate binary known to date. The inclination of the accretion disk with respect to the line of sight is estimated to be 65-80 degrees. We suggest the companion to the black-hole candidate to be an M5 dwarf star, with a mass and radius of about 0.2-0.3 M_sun and 0.2-0.25 R_sun, respectively. We find that the companion had an initial mass of about 1.5 M_sun, which evolved to its current mass in about 5-6 billion years. The system is rather compact (orbital separation of about 1.33 R_sun), and is located at a distance of about 8.6 kpc, with a height above the Galactic plane of about 2.4 kpc. The characteristics of short orbital period and high Galactic scale height are shared with two other transient black-hole candidate X-ray binaries, i.e., XTE J1118+480 and Swift J1735.5-0127. All three are kicked out of the Galactic plane into the halo, rather than being formed in a globular cluster.
Belloni Tomaso
Cadolle Bel Marion
den Heuvel Edward P. J. van
der Horst Alexander J. van
Diaz Trigo Maria
No associations
LandOfFree
MAXI J1659-152: The shortest orbital period black-hole transient in outburst does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with MAXI J1659-152: The shortest orbital period black-hole transient in outburst, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and MAXI J1659-152: The shortest orbital period black-hole transient in outburst will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-313707