Dependence of the LMXB population on the stellar age

Details Dependence of the LMXB population on the stellar age Dependence of the LMXB population on the stellar age

2012-02-10

arxiv.org/abs/1202.2331v1

Astronomy and Astrophysics

Astrophysics

High Energy Astrophysical Phenomena

11 pages, 8 figures, submitted to A&A

Scientific paper

We investigate the dependence of the LMXB population in early-type galaxies on the stellar age. We selected 20 massive nearby early-type galaxies from the Chandra archive occupying relatively narrow range of masses and spanning broad range of ages, from 1.6 Gyr to more than 10 Gyrs, with the median value of 6 Gyrs. With ~ 2000 X-ray point sources detected in total, we correlated the specific number of LMXBs in each galaxy with its stellar age and globular cluster content. We found a correlation between the LMXB population and the stellar age -- older galaxies tend to possess about ~ 50% more LMXBs (per unit stellar mass) than the younger ones. The interpretation of this dependence is complicated by large scatter and a rather strong correlation between the stellar age and the globular cluster content of galaxies in our sample. We present evidence suggesting that the more important factor is the evolution of the LMXB population with time. Its effect is further amplified by the larger globular content of older galaxies and correspondingly, larger numbers of dynamically formed binaries in them. We also found clear evolution of the X-ray luminosity function with age, that younger galaxies have more bright sources and fewer faint sources per unit stellar mass. The luminosity function of LMXBs in younger galaxies appears to extend significantly beyond E39 erg/s. Such bright sources seem to be less frequent in older galaxies. We found that 3 out of ~ 8 (ultra-) luminous sources are located in globular clusters.

Affiliated with

Also associated with

No associations

Rating

Dependence of the LMXB population on the stellar age 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 Dependence of the LMXB population on the stellar age, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dependence of the LMXB population on the stellar age will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-276271