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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 h100-2erg/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 0.25h100-1Mpc (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 0.5h100-1Mpc (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*H0p) (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
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