RASSCNDINS ivo://nasa.heasarc/rasscndins NASA/GSFC HEASARC Turner et al. 2026-10-02 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source Using new and archival observations made with the Swift satellite and other facilities, the authors 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 (kT<sub>eff</sub> < 200 eV), non-variable X-ray sources - as in a previous study - yields an all-sky limit of <= 31 INSs. In the course of their analysis, the authors identify 5 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. Following selection of the INS candidates, short (~ 1 ks) follow-up observations with Swift/XRT were obtained for 92 of the candidates; these observations decreased the X-ray positional uncertainty (the systematic positional error associated with Swift blind pointing observations is on the order of 3.5"). The authors obtained (where possible) contemporaneous UV observations with Swift/UVOT for counterpart identification with off-band objects. This table was created by the HEASARC in May 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/714/1424">CDS Catalog J/ApJ/714/1424</a> files table1.dat and table2.dat. This is a service provided by NASA HEASARC . 2010ApJ...714.1424T https://heasarc.gsfc.nasa.gov/W3Browse/all/rasscndins.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=rasscndins& GET text/xml 180 99999 true 42.44166667 -38.42777778 0.0333333333333333 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=rasscndins GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_rasscndins&Action=More+Options&Action=Parameter+Search&ConeAdd=1 STAR CATALOG 0.0333333333333333 Optical public rasscndins ROSAT All-Sky Survey Candidate Isolated Neutron Stars name ROSAT Source Identification (1RXS JHHMMSS.s+DDMMSS) meta.id;meta.main char nullable alt_name Name meta.id char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable hardness_ratio Hardness Ratio phot.flux;arith.ratio;em.X-ray.soft double nullable source_type Source Type src.class char nullable ins_category Object Categorization (INS, Not an INS, or Undetermined) src.class char nullable xrt_name XRT Identification (Swift XRT JHHMMSS.s+DDMMSS.s) meta.id.cross char nullable uvot_name UVOT Identification (Swift UVOT JHHMMSS.s+DDMMSS.s) meta.id.cross char nullable "__x_ra_dec" System unit vector column double nullable "__y_ra_dec" System unit vector column double nullable "__z_ra_dec" System unit vector column double nullable "__row" System index column char nullable log_chance_prob_2mx Logarithm Probability of Chance Association Between 2MASS and XRT Source stat.probability double nullable swift_obsid Swift/XRT Observation Identifier meta.id;obs char nullable bii Galactic Latitude degree pos.galactic.lat double nullable twomass_name 2MASS Identification (2MASS JHHMMSS.s+DDMMSS.s) meta.id.cross char nullable source_flag Flag [hij] on Class meta.code;src char nullable log_chance_prob_usx Logarithm Probability of Chance Association Between USNO and XRT Source stat.probability double nullable lii Galactic Longitude degree pos.galactic.lon double nullable xray_follow_up Observation Facility meta.code char nullable log_chance_prob_ux Logarithm Probability of Chance Association Between UVOT and XRT Source stat.probability double nullable log_chance_prob_2mu Logarithm Probability of Chance Association Between 2MASS and UVOT Source stat.probability double nullable log_chance_prob_usu Logarithm Probability of Chance Association Between USNO and UVOT Source stat.probability double nullable usno_name USNO Identification (USNO JHHMMSS.s+DDMMSS.s) meta.id.cross char nullable rass_xrt_offset Separation Between RASS/BSC Source and Swift Source arcsec pos.angDistance;em.X-ray double nullable prob_no_id Probability That RASS Source Is Not Associated with Off-Band Catalog Sources stat.probability double nullable class Browse Object Classification src.class short nullable