J/ApJ/539/136 Properties of poor groups of galaxies. III. (Zabludoff+, 2000)
The properties of poor groups of galaxies. III. The galaxy luminosity function.
Zabludoff A.I., Mulchaey J.S.
<Astrophys. J. 539, 136 (2000)>
=2000ApJ...539..136Z 2000ApJ...539..136Z
ADC_Keywords: Clusters, galaxy ; Radial velocities ; Magnitudes
Keywords: cosmology: large - scale structure of Universe -
galaxies: clusters: general - galaxies: evolution -
galaxies: luminosity function, mass function
Abstract:
The form of the galaxy luminosity function (GLF) in poor groups -
regions of intermediate galaxy density that are common environments
for galaxies - is not well understood. Multiobject spectroscopy and
wide-field CCD imaging now allow us to measure the GLF of bound group
members directly (i.e., without statistical background subtraction)
and to compare the group GLF with the GLFs of the field and of rich
clusters. We use R-band images in 1.5x1.5degree2 mosaics to obtain
photometry for galaxies in the fields of six nearby (2800<cz<7700km/s)
poor groups for which we have extensive spectroscopic data, including
328 new galaxy velocities.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 66 742 Galaxy data
table2.dat 77 6 Group properties
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See also:
J/ApJ/496/39 : Properties of poor groups of galaxies. I. (Zabludoff+ 1998)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Galaxy name
14- 15 I2 h RAh Right Ascension (J2000)
18- 19 I2 min RAm Right Ascension (J2000)
22- 25 F4.1 s RAs Right Ascension (J2000)
30 A1 --- DE- Sign of the Declination (J2000)
31- 32 I2 deg DEd Declination (J2000)
35- 36 I2 arcmin DEm Declination (J2000)
39- 40 I2 arcsec DEs Declination (J2000)
47- 51 I5 km/s HRV Heliocentric radial velocity from NED
55- 57 I3 km/s e_HRV Uncertainty in HRV
60 I1 --- f_HRV Flag on the type of velocity measurement (1)
63- 66 F4.1 mag Rmag ? Magnitude in the R band
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Note (1): Type of velocity measurement:
0: Velocity measured from absorption lines
1: Velocity measured from emission lines
2: Velocity measured from a combination of absorption and emission lines
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Group Group name (4)
10- 11 I2 h RAh Right ascension of the group optical
projected centroid in J2000
13- 14 I2 min RAm Right ascension of the group optical
projected centroid in J2000
16- 19 F4.1 s RAs Right ascension of the group optical
projected centroid in J2000
21 A1 --- DE- Declination sign
22- 23 I2 deg DEd Declination of the group optical
projected centroid in J2000
25- 26 I2 arcmin DEm Declination of the group optical
projected centroid in J2000
28- 29 I2 arcsec DEs Declination of the group optical
projected centroid in J2000
31- 32 I2 --- Ngroup Number of group members (1)
34- 37 I4 km/s Mean heliocentric velocity (1)
39- 40 I2 km/s e_ rms uncertainty on
42- 44 I3 km/s sigma Line-of-sight velocity dispersion
46- 47 I2 km/s E_sigma Error on sigma (upper limit)
49- 50 I2 km/s e_sigma Error on sigma (lower limit)
52- 55 F4.1 [10-7W] logLx X-ray luminosity (2)
57- 60 F4.2 Mpc rsample Sampling radius for the photometry
62- 63 I2 --- N'grp Number of members within rsample (4) (3)
65- 69 F5.1 Mpc-3 n0,4 Corrected number density of galaxies (5)
71- 73 F3.1 --- D/G0.4 Dwarf-to-giant ratio (6)
75- 77 F3.1 --- e_D/G0.4 rms uncertainty on D/G0.4
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Note (1): Calculated within rsamp except for NGC 4325 (within 1.0h-1Mpc)
and NGC 5129 (within0.9h-1Mpc)
Note (2): From Mulchaey & Zabludoff (1998ApJ...496...73M 1998ApJ...496...73M)
except for NGC 3557 (this paper)
Note (3): Calculated within rsamp
Note (4): For HGC 42, Ngrp{diff}N'grp because one member lies outside
photometric survey boundary.
For NGC 3557, marginally-detected in X-rays
Note (5): Corrected number density of galaxies with MR≤-17+5logh,
within 0.4h-1Mpc of the group center and assuming spherical symmetry
Note (6): Dwarf-to-giant ratio for galaxies with MR≤-17+5logh and
within 0.4h-1Mpc
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History: From ApJ electronic version
References:
Zabudoff & Mulchaey, Paper I 1998ApJ...496...39Z 1998ApJ...496...39Z, Cat. J/ApJ/496/39
Mulchaey & Zabudoff, Paper II 1998ApJ...496...73M 1998ApJ...496...73M
(End) Greg Schwartz [AAS], Patricia Bauer [CDS] 29-Aug-2000