A Limit on the Number of Isolated Neutron Stars Detected in the ROSAT All-Sky Survey Bright Source Catalog

Autor:	Turner, Monica L., Rutledge, Robert E., Letcavage, Ryan, Shevchuk, Andrew S. H., Fox, Derek B.
Rok vydání:	2010
Předmět:	Astrophysics - High Energy Astrophysical Phenomena Astrophysics - Astrophysics of Galaxies
Druh dokumentu:	Working Paper
DOI:	10.1088/0004-637X/714/2/1424
Popis:	Using new and archival observations made with the Swift satellite and other facilities, we examine 147 X-ray sources selected from the ROSAT All-Sky-Survey Bright Source Catalog (RASS/BSC) to produce a new limit on the number of isolated neutron stars (INSs) in the RASS/BSC, the most constraining such limit to-date. Independent of X-ray spectrum and variability, the number of INSs is <=48 (90% confidence). Restricting attention to soft (having an effective temperature of < 200 eV), non-variable X-ray sources -- as in a previous study -- yields an all-sky limit of <=31 INSs. In the course of our analysis, we identify five new high-quality INS candidates for targeted follow-up observations. A future all-sky X-ray survey with eROSITA, or another mission with similar capabilities, can be expected to increase the detected population of X-ray-discovered INSs from the 8 to 50 in the BSC, to (for a disk population) 240 to 1500, which will enable a more detailed study of neutron star population models. Comment: 35 pages, accepted for publication in ApJS.
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1003.3955 Zobrazit plný text záznamu View this record from Arxiv