J/ApJ/714/1424 Isolated neutron stars from Rosat and Swift (Turner+, 2010)
A limit on the number of isolated neutron stars detected in the ROSAT All-Sky-Survey Bright Source Catalog. Turner M.L., Rutledge R.E., Letcavage R., Shevchuk A.S.H., Fox D.B. <Astrophys. J., 714, 1424-1440 (2010)> =2010ApJ...714.1424T
ADC_Keywords: X-ray sources ; Cross identifications ; Pulsars Keywords: stars: neutron - X-rays: stars Abstract: 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 (kTeff<200eV), 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 8-50 in the BSC, to (for a disk population) 240-1500, which will enable a more detailed study of neutron star population models. Description: Following selection of the isolated neutron star (INS) candidates, short (∼1ks) follow-up observations with Swift/XRT were obtained on 92 of the candidates; these observations decrease the X-ray positional uncertainty (the systematic positional error associated with Swift blind pointing observations is on the order of 3.5"), and obtain (where possible) contemporaneous UV observations with Swift/UVOT for counterpart identification with off-band objects. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 109 147 Candidates RASS/BSC sources and identifications table2.dat 149 77 Objects observed and detected with Swift/XRT
See also: IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999) J/A+A/527/A139 : X-ray bursting neutron star atmosphere models (Suleimanov+, 2011) J/A+A/473/523 : Spectroscopic monitoring of 3 neutron stars (Van der Meer+, 2007) http://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/swift.pl : Swift mission archive Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 16 A16 --- 1RXS Source identification (JHHMMSS.s+DDMMSS) 18- 22 F5.3 --- Pnoid The probability Pno-id that each RASS/BSC X-ray source was not associated with any of the off-band catalog sources (section 2.1) 24- 55 A32 --- Type Source type 57- 85 A29 --- Name Alternative Name 87- 90 A4 --- Obs Observation facility (1) 92- 96 F5.2 --- HR Hardness ratio 98-109 A12 --- Class Object identification ("INS", "Not an INS", or "Undetermined")
Note (1): Facilities: C, Chandra; X, XMM; H, ROSAT; S, Swift.
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 16 A16 --- 1RXS Source identification (JHHMMSS.s+DDMMSS) 18- 28 A11 --- ObsID Swift/XRT observation ID 30- 47 A18 --- XRT XRT identification (JHHMMSS.s+DDMMSS.s) 49- 53 F5.1 arcsec R Separation R between RASS/BSC source and Swift source 55- 72 A18 --- UVOT UVOT identification (JHHMMSS.s+DDMMSS.s) 74- 77 F4.1 [-] Px ? Log probability of chance association between UVOT and XRT source 79- 96 A18 --- 2MASS 2MASS identification (JHHMMSS.s+DDMMSS.s) 98-101 F4.1 [-] Px2 ? Log probability of chance association between 2MASS and XRT source 103-106 F4.1 [-] PU ? Log probability of chance association between 2MASS and UVOT source 108-125 A18 --- USNO USNO identification (JHHMMSS.s+DDMMSS.s) 127-130 F4.1 [-] PxU ? Log probability of chance association between USNO and XRT source 132-135 F4.1 [-] PUU ? Log probability of chance association between USNO and UVOT source 137-148 A12 --- Class Object classification ("INS", "Not an INS", or "Undetermined") 149 A1 --- f_Class [hij] Individual remarks (1)
Note (1): Flag as follows: h = XRT source found to be extended. i = XRT source saturated. j = During the process of this work, identified as an isolated neutron star (Calvera) (Rutledge et al. 2008ApJ...672.1137R).
History: From electronic version of the journal
(End) Emmanuelle Perret [CDS] 23-Apr-2012
|The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line|