Exploring the Small Magellanic Cloud to the Faintest X-ray Fluxes: Source Catalog, Timing, and Spectral Analysis
Abstract
We present the results of a pair of 100 ks Chandra observations in the Small Magellanic Cloud (SMC) to survey high-mass X-ray binaries (HMXBs), stars, and low-mass X-ray binaries (LMXBs)/cataclysmic variables down to Lx = 4.3 × 1032 erg s-1. The two SMC Deep Fields (DFs) are located in the most active star-forming region of the bar, with Deep Field-1 positioned at the most pulsar-rich location identified from previous surveys. Two new pulsars were discovered in the outburst: CXOU J004929.7-731058 (P = 892 s), CXOU J005252.2-721715 (P = 326 s), and three new HMXB candidates were identified. Of the 15 Be-pulsars now known in the field, 13 were detected, with pulsations seen in 9 of them. Ephemerides demonstrate that 6 of the 10 pulsars known to exhibit regular outbursts were seen outside their periastron phase, and quiescent X-ray emission at LX = 1033-1034 erg s-1 is shown to be common. Comparison with ROSAT, ASCA, and XMM-Newton catalogs resulted in positive identification of several previously ambiguous sources. Bright optical counterparts exist for 40 of the X-ray sources, of which 33 are consistent with early-type stars (MV < -2, B - V < 0.2), and are the subject of a companion paper. The results point to an underlying HMXB population density up to double that of active systems. The full catalog of 394 point sources is presented along with detailed analyses of timing and spectral properties.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 2010
- DOI:
- 10.1088/0004-637X/716/2/1217
- arXiv:
- arXiv:0809.1738
- Bibcode:
- 2010ApJ...716.1217L
- Keywords:
-
- Magellanic Clouds;
- stars: emission-line;
- Be;
- stars: neutron;
- X-rays: binaries;
- Astrophysics
- E-Print:
- Published in The Astrophysical Journal. This version replaces the original manuscript (arXiv:0809.1738) to reflect changes made in the final published article