Barnard, R.; Shaw Greening, L.; Tonkin, C.; Kolb, U. and Osborne, J. P.
(2006).
| DOI (Digital Object Identifier) Link: | http://dx.doi.org/10.1017/S174392130600809X |
|---|---|
| Google Scholar: | Look up in Google Scholar |
Abstract
We have conducted a survey of X-ray sources in XMM-Newton observations of M31, examining their power density spectra (PDS) and spectral energy distributions (SEDs). Our automated source detection yielded 535 good X-ray sources; to date, we have studied 225 of them. In particular, we examined the PDS because low mass X-ray binaries (LMXBs) exhibit two distinctive types of PDS. At low accretion rates, the PDS is characterised by a broken power law, with the spectral index changing from ∼0 to ∼1 at some frequency in the range ∼0.01-1 Hz; we refer to such PDS as Type A. At higher accretion rates, the PDS is described by a simple power law; we call these PDS Type B. Of the 225 sources studied to date, 75 exhibit Type A variability, and are almost certainly LMXBs, while 6 show Type B but not Type A, and are likely LMXBs. Of these 81 candidate LMXBs, 71 are newly identified in this survey; furthermore, they are mostly found near the centre of M31. Furthermore, most of the X-ray population in the disc are associated with the spiral arms, making them likely high mass X-ray binaries (HMXBs). In general these HMXBs do not exhibit Type A variability, while many central X-ray sources (LMXBs) in the same luminosity range do. Hence the PDS may distinguish between LMXBs and HMXBs in this luminosity range.
| Item Type: | Conference Item |
|---|---|
| ISSN: | 1743-9213 |
| Extra Information: | Some of the symbols may not have transferred correctly into this bibliographic record and/or abstract. |
| Academic Unit/Department: | Science > Physical Sciences |
| Interdisciplinary Research Centre: | Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR) eSTEeM |
| Item ID: | 6035 |
| Depositing User: | Christopher Biggs |
| Date Deposited: | 18 Dec 2006 |
| Last Modified: | 05 Mar 2014 10:27 |
| URI: | http://oro.open.ac.uk/id/eprint/6035 |
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