RASS-CALS ivo://nasa.heasarc/rasscals NASA/GSFC HEASARC Mahdavi, Bohringer, Geller, Ramella 2026-04-03 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Galaxy Group This table contains the catalog from the ROSAT All-Sky Survey (RASS) Center for Astrophysics (CfA) Loose Systems, or RASSCALS, the largest X-ray and optical survey of low-mass galaxy groups as of its publication date in 2000. The authors drew 260 groups from the combined Center for Astrophysics and Southern Sky Redshift Surveys, covering one-quarter of the sky to a limiting Zwicky magnitude of m<sub>z</sub> = 15.5. They detected 61 groups (23%) as extended X-ray sources. The X-ray detections have a median membership of nine galaxies, a median recession velocity cz = 7250 km/s, a median projected velocity dispersion sigma(p) = 400 km/s, and a median X-ray luminosity L(x) = 3 x 10<sup>42</sup> /h(100)<sup>2</sup> erg/s, where the Hubble constant is H(0) = 100 h(100) km/s/Mpc. The data in this table replace the preliminary analysis of the X-ray data which was presented in Mahdavi et al., 1999, ApJ, 518, 69 (CDS Cat. <J/ApJ/518/69>. This table was created by the HEASARC in September 2005 based on CDS tables J/ApJ/534/114/table2.dat & table3.dat. This is a service provided by NASA HEASARC . 2000ApJ...534..114M https://heasarc.gsfc.nasa.gov/W3Browse/all/rasscals.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=rasscals& GET text/xml 180 99999 true 23.73875 -39.04277778 0.05 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=rasscals GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_rasscals&Action=More+Options&Action=Parameter+Search&ConeAdd=1 GALAXY CATALOG 0.05 X-ray public rasscals ROSAT All-Sky Survey CALS Galaxy Groups Catalog log_lx_r_xi Log10 of X-ray Luminosity at NOCORE Radius (in h_100_^-2 ergs/s) 10^-7_W phys.luminosity;em.X-ray.soft float nullable r_xi_error RMS Uncertainty in NOCORE Radius (Mpc) Mpc stat.error;phys.size.radius float nullable lii Galactic Longitude degree pos.galactic.lon double nullable log_lx_r_xi_error RMS Uncertainty in Log10 of X-ray Luminosity at NOCORE Radius 10^-7_W stat.error;phys.luminosity;em.X-ray.soft float nullable "__z_ra_dec" System unit vector column double nullable log_lx_p25 Log10 of X-ray Luminosity within 0.25h_100_^-1 Mpc (in h_100_^-2 ergs/s) 10^-7_W phys.luminosity;em.X-ray.soft float nullable log_lx_p5_error RMS Uncertainty in Log10 of X-ray Luminosity log(10^-7_W) stat.error;phys.luminosity;em.X-ray.soft float nullable "__y_ra_dec" System unit vector column double nullable "__row" System index column char nullable f_spiral Fraction of Group Members That Are Spiral Galaxies src.class;arith.ratio float nullable log_lx_p5_limit Limit Flag for X-ray Luminosity meta.code;phys.luminosity;em.X-ray.soft char nullable log_lx_p5_flag Flag [d] Indicates X-ray Detection Only Due to Finding Algorithm Confusion meta.code;phys.luminosity;em.X-ray.soft char nullable bii Galactic Latitude degree pos.galactic.lat double nullable name Object Designation meta.id;meta.main char nullable r_xi NOCORE Radius of Detected Groups (Mpc) Mpc phys.size.radius float nullable n_17 Number of Group Members Brighter Than Absolute Magnitude -17 meta.number short nullable alt_names Other Identifications meta.id char nullable log_time_cross Log10 of Crossing Time (=Rxi*H_0/{sigma}_p) in H_0^-1 time.crossing float nullable dec Declination degree pos.eq.dec;meta.main double nullable radial_velocity_error RMS Uncertainty in Recession Velocity (km/s) km/s stat.error;spect.dopplerVeloc;pos.heliocentric short nullable log_sigma_p_error RMS Uncertainty in Log10 of Velocity Dispersion in km/s log(km/s) stat.error;phys.veloc.dispersion float nullable radial_velocity Recession Velocity (km/s) km/s spect.dopplerVeloc;pos.heliocentric short nullable "__x_ra_dec" System unit vector column double nullable log_lx_p5 Log10 of X-ray Luminosity in 0.1-2.4keV Band (in 10^-7 W) log(10^-7_W) phys.luminosity;em.X-ray.soft float nullable n_group Number of Group Members meta.number short nullable log_time_cross_error RMS Uncertainty in Log10 of Crossing Time in H_0^-1 stat.error;time.crossing float nullable log_lx_p25_error RMS Uncertainty in Log10 of X-ray Luminosity 0.25 10^-7_W stat.error;phys.luminosity;em.X-ray.soft float nullable log_sigma_p Velocity Dispersion of the Dark Matter Halo in Which the Galaxies Are Embedded log(km/s) phys.veloc.dispersion float nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable