X-ray Luminosity Function of LMXBs in Elliptical Galaxies
Abstract
The X-ray luminosity function of LMXBs is one of the key observables which can be directly compared with theoretical models to better understand the formation and evolution of LMXBs and corresponding star formation episodes in elliptical galaxies. I will review the current status of LMXB XLFs with particular emphases on (1) an XLF break at Lx = 5 x 1038 erg s-1 which is likely dividing NS and BH binaries, (2) significantly flattened XLF at low luminosities (Lx < 5 x 1037 erg s-1) of GC-LMXBs (compared to that of field LMXBs) which suggests two distinct LMXB formation mechanisms, and (3) significantly flattened LMXB XLF at high luminosities (Lx > 5 x 1038 erg s-1) in young elliptical galaxies (compared to typical old ellipticals) , indicating that more luminous LMXBs (including ULXs) present in young elliptical galaxies which are possibly associated with recent mergers.
- Publication:
-
AAS/High Energy Astrophysics Division #11
- Pub Date:
- March 2010
- Bibcode:
- 2010HEAD...11.2006K