{ "id": "astro-ph/0301443", "version": "v3", "published": "2003-01-22T15:09:23.000Z", "updated": "2003-03-26T15:02:50.000Z", "title": "BeppoSAX observations of two unclassified LMXBs: X1543-624 and X1556-605", "authors": [ "R. Farinelli", "F. Frontera", "N. Masetti", "L. Amati", "C. Guidorzi", "M. Orlandini", "E. Palazzi", "A. N. Parmar", "L. Stella", "M. Van der Klis", "S. N. Zhang" ], "comment": "13 pages, 16 figures, accepted for publication by A&A. Final version after copy editor corrections. Error bars and typo corrected in Fig. 3", "journal": "Astron.Astrophys. 402 (2003) 1021-1032", "doi": "10.1051/0004-6361:20030165", "categories": [ "astro-ph" ], "abstract": "Observations of two unclassified Low Mass X-ray Binaries, X1543-624 and X1556-605, are presented. In the 2-10 keV band the first of the two sources is a factor two stronger than the other. Both sources do not show X-ray bursts, dips or eclipses in their X-ray light curves. We find that both spectra are described by a two-component model consisting of emission from a cool accretion disk plus a Comptonized blackbody with kTbb ~ 1.5 keV in a low opacity plasma. The spectrum of X1543-624 hardens from the first to the second observation, when the source slowly moves from right to left in the colour-colour diagram. The spectrum of X1556-605 can also be described by a model consisting of a blackbody plus an unsaturated Comptonization with electron energy kTe ~ 4 keV. In the first observation, X1543-624 shows evidence of a Fe K emission line at 6.4 keV. Moreover in both observations, the source spectrum exhibits an emission feature around 0.7 keV, which is interpreted as due to the superposition of the K edge absorption features of O and Ne elements with uncommon relative abundances with respect to the solar one (O/O(sun) ~0.3, Ne/Ne(sun) ~ 2.5). In the spectrum of X1556-605 no emission lines are observed. We discuss these results and their implications on the source classification and the accretion geometry on the compact object.", "revisions": [ { "version": "v3", "updated": "2003-03-26T15:02:50.000Z" } ], "analyses": { "keywords": [ "bepposax observations", "unclassified lmxbs", "cool accretion disk plus", "emission line", "unclassified low mass x-ray binaries" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable", "inspire": 612043 } } }