M51CXO ivo://nasa.heasarc/m51cxo NASA/GSFC HEASARC Terashima, Wilson 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains the results of two Chandra observations (separated by 1 year) of the population of X-ray sources in the spiral galaxy M 51 (NGC 5194 and NGC 5195). One hundred and thirteen X-ray sources have been detected in an 8.4' x 8.4'(20.4 x 20.4kpc) region, and 84 and 12 of them project within the disks of NGC 5194 and NGC 5195, respectively. Nine and 28 sources have luminosities exceeding 1 x 10<sup>39</sup> erg/s (ultraluminous X-ray sources or ULXs) and 1 x 10<sup>38</sup> erg/s in the 0.5 - 8 keV band, respectively, assuming that they are associated with M 51. The number of ULXs is much higher than found in most normal spiral and elliptical galaxies. Most of the X-ray sources and all seven of the ULXs in NGC 5194 are located in, or close to, a spiral arm, suggesting a connection with recent star formation. The Chandra observations of M 51 were performed on 2000 June 20 and 2001 June 23 with the ACIS instrument. The background was stable in both observations, and effective exposure times of 14.9 and 26.8ks were obtained for the observations in 2000 and 2001, respectively. This table was created by the HEASARC in March 2007 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/601/735">CDS catalog J/ApJ/601/735</a> files table2.dat, table3.dat and table4.dat. This is a service provided by NASA HEASARC . 2004ApJ...601..735T https://heasarc.gsfc.nasa.gov/W3Browse/all/m51cxo.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=m51cxo& GET text/xml 180 99999 true 202.52695833 47.14286111 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=m51cxo GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_m51cxo&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CHANDRA 0.0166666666666667 X-ray public m51cxo M 51 Chandra X-Ray Discrete Source Catalog name Chandra Designation meta.id;meta.main char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable fb_counts 0.5-8keV Band Counts in Observations 1 & 2 ct double nullable fb_counts_error RMS Uncertainty on 0.5-8keV Band Counts ct double nullable hb_counts_limit Limit Flag for 2-8keV char nullable hb_counts 2-8keV Band Counts in Observations 1 & 2 ct double nullable hb_counts_error RMS Uncertainty on 2-8keV Band Counts ct double 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 hb_counts_obs2 2-8keV Band Counts in Observation 2 ct double nullable sb_counts_obs2_limit Limit Flag for 0.5-2keV Band Counts in Observation 2 char nullable hb_counts_obs1 2-8keV Band Counts in Observation 1 ct double nullable fb_counts_obs2_error RMS Uncertainty on 0.5-8keV Band Counts in Observation 2 ct double nullable sb_counts_obs1_error RMS Uncertainty on 0.5-2keV Band Counts in Observation 1 ct double nullable alt_name Alternative Designation meta.id char nullable fb_counts_obs1_limit Limit Flag for 0.5-8keV Band Counts in Observation 1 char nullable table_number Table Number short nullable hb_counts_obs1_limit Limit Flag for 2-8keV Band Counts in Observation 1 char nullable hb_counts_obs2_error RMS Uncertainty on 2-8keV Band Counts in Observation 2 ct double nullable source_number Sequential Number Assigned to Each Source on a Per Table Basis meta.id short nullable sb_counts_obs1_limit Limit Flag for 0.5-2keV Band Counts in Observation 1 char nullable sb_counts_obs2_error RMS Uncertainty on 0.5-2keV Band Counts in Observation 2 ct double nullable hb_counts_obs1_error RMS Uncertainty on 2-8keV Band Counts in Observation 1 ct double nullable fb_counts_obs2 0.5-8keV Band Counts in Observation 2 ct double nullable fb_counts_obs2_limit Limit Flag for 0.5-8keV Band Counts in Observation 2 char nullable sb_counts_obs1 0.5-2keV Band Counts in Observation 1 ct double nullable sb_counts_obs2 0.5-2keV Band Counts in Observation 2 ct double nullable fb_counts_obs1_error RMS Uncertainty on 0.5-8keV Band Counts in Observation 1 ct double nullable sb_counts_limit Limit Flag for 0.5-2keV Band Counts char nullable hb_counts_obs2_limit Limit Flag for 2-8keV Band Counts in Observation 2 char nullable fb_counts_obs1 0.5-8keV Band Counts in Observation 1 ct double nullable sb_counts_error RMS Uncertainty on 0.5-2keV Band Counts ct double nullable lii Galactic Longitude degree pos.galactic.lon double nullable sb_counts 0.5-2keV Band Counts in Observations 1 & 2 ct double nullable bii Galactic Latitude degree pos.galactic.lat double nullable