Access to Astronomical Catalogues

← Click to display the menu
J/ApJ/534/114       RASSCALS:  X-ray and optical study       (Mahdavi+, 2000)

The RASSCALS: an X-ray and optical study of 260 galaxy groups. Mahdavi A., Bohringer H., Geller M.J., Ramella M. <Astrophys. J. 534, 114 (2000)> =2000ApJ...534..114M
ADC_Keywords: Clusters, galaxy ; X-ray sources ; Redshifts ; Velocity dispersion Keywords: galaxies: clusters: general - galaxies: statistics Abstract: We describe the ROSAT All-Sky Survey Center for Astrophysics Loose Systems (RASSCALS), the largest X-ray and optical survey of low-mass galaxy groups to date. We draw 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 mz=15.5. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 91 260 *The RASSCALS: Basic Properties table3.dat 76 59 *The RASSCALS: Detailed Properties table4.dat 30 25 Cluster data
Note on table2.dat: The data in this table replace the preliminary analysis of the X-ray data in Mahdavi et al., 1999, Cat. J/ApJ/518/69. Note on table3.dat: Data for the detected groups, excluding the optically spoiled clusters NRGs372 and NRGs392. The 0.1-2.4 keV X-ray luminosities are computed within 0.25h100-1Mpc and 0.5h100-1Mpc, as well as within the NOCORE radius, Rxi.
See also: J/ApJ/518/69 : Deep Optical Catalog of galaxy systems (Mahdavi+, 1999) Table 1: Sky Coverage of the Optical Group Catalog -------------------------------------------------------------------------------- Field Name RA (2000) DE (h) (deg) -------------------------------------------------------------------------------- NRG 8.5-17 8.5-43.5 SRG 21.5-03 -2-32 SS2 a 21-05 -40-1.5 SS2 b 10-15 -26-0 -------------------------------------------------------------------------------- Notes: a: First portion, excluding sections with Galactic latitude b<40° b: Second portion, excluding sections with Galactic latitude b<40° Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 7 A7 --- RASSCALS Object designation (1) 9- 10 I2 h RAh Right ascension (J2000.0) (2) 12- 13 I2 min RAm Right ascension (J2000.0) 15- 18 F4.1 s RAs Right ascension (J2000.0) 20 A1 --- DE- Declination sign (J2000.0) 21- 22 I2 deg DEd Declination (J2000.0) 24- 25 I2 arcmin DEm Declination (J2000.0) 27- 28 I2 arcsec DEs Declination (J2000.0) 30- 32 I3 --- N Number of group members 34- 37 I4 --- N17 Number of group members brighter than an absolute magnitude MZ=-17, corresponding to mZ=15.5 for a group at cz=3200km/s 39- 43 I5 km/s cz Recession velocity 45- 47 I3 km/s e_cz rms uncertainty on cz 49- 52 F4.2 [km/s] logsigmap Velocity dispersion of the dark matter halo in which the galaxies are embedded 54- 57 F4.2 [km/s] e_logsigmap rms uncertainty on logsigmap 59 A1 --- l_logLX Limit flag on logLX 60- 64 F5.2 [10-7W] logLX ? X-ray luminosity (in h_100_^-2^erg/s) (3) 66- 69 F4.2 [10-7W] e_logLX ? rms uncertainty on logLX 70 A1 --- n_logLX [d] Note (4) 72- 91 A20 --- Names Other identifications (5)
Note (1): We first assign each system a seven-character name, beginning with "NRG," "SRG," or SS2," followed by "b" or "s" (specifying the angular size of the system as "big," with cz<8500km/s or "small," with cz>8500km/s, respectively), followed by a three-digit number. Note (2): For the 59 groups with a listed X-ray luminosity, we report the X-ray centroid; for the others we report the mean RA and DE of the galaxies in the group. Note (3): Luminosity in the 0.1-2.4keV band within an aperture Note (4): Two X-ray luminous Abell clusters which the optical group finding algorithm has confused with the field. We count these as detections but do not calculate their other X-ray properties. Note (5): By no means complete. A: Abell (Cat. VII/4) cluster AWM: Albert et al. (1977ApJ...211..309A) Groups HCG: Hickson Compact Groups (Hickson, 1982, Cat. VII/213) MGBR: Studied in greater detail in Mahdavi et al. 1999 MKW: Morgan, Kayser, & White (1975ApJ...199..545M) Groups PPS: Loose Groups in the Perseus-Pisces Survey (Trasarti-Battistoni, 1998, Cat. J/A+AS/130/341) ZM: Zabludoff & Mulchaey (1998, Cat. J/ApJ/496/39) Poor Groups
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 7 A7 --- RASSCALS Object designation 9- 12 F4.2 [km/s] logsigmap Pojected velocity dispersion 14- 17 F4.2 [km/s] e_logsigmap rms uncertainty on logsigmap 19- 23 F5.2 [10-7W] logLX(0.25) X-ray luminosity within 0.25h_100_^-1^Mpc (1) 25- 28 F4.2 [10-7W] e_logLX(0.25) rms uncertainty on logLX(0.25) (1) 30- 34 F5.2 [10-7W] logLX(0.5) X-ray luminosity within 0.5h_100_^-1^Mpc (1) 36- 39 F4.2 [10-7W] e_logLX(0.5) rms uncertainty on logLX(0.5) (1) 41- 45 F5.2 [10-7W] logLX(Rxi) X-ray luminosity at NOCORE radius (1) 47- 50 F4.2 [10-7W] e_logLX(Rxi) rms uncertainty on logLX(Rxi) (1) 52- 55 F4.2 Mpc Rxi NOCORE radius of detected groups (2) (3) 57- 60 F4.2 Mpc e_Rxi rms uncertainty on Rxi 62- 66 F5.2 --- logtc Crossing time (=Rxi*H_0_/σ_p_) (2) 68- 71 F4.2 --- e_logtc rms uncertainty on logtc 73- 76 F4.2 --- fsp Fraction of group member that are spiral galaxies
Note (1): in h100-2ergs/s Note (2): in H0-1 Note (3): NOCORE: Nonparametric Core Radius Estimator (Mahdavi, 2000, in prep.)
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Cluster Cluster name 10- 14 F5.3 --- z Redshift 16- 20 F5.2 10-7W logLX 0.1-2.4 keV band X-ray luminosity (1) 22- 25 F4.2 [km/s] logsigmap Projected dispersion velocity (2) 27- 30 F4.2 [km/s] e_logsigmap rms uncertainty on logsigmap
Note (1): X-ray luminosity from Markevitch, 1998ApJ...504...27M, in h100-2ergs/s. We take uncertainty in the luminosities to be 20%. Note (2): From Fadda et al., 1996ApJ...473..670F.
History: From ApJ electronic version
(End) James Marcout, Patricia Bauer [CDS] 31-Aug-2000
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

catalogue service