J/MNRAS/370/1223 Dynamical properties of 15 nearby galaxy groups (Brough+, 2006)
Southern GEMS groups. I. Dynamical properties.
Brough S., Forbes D.A., Kilborn V.A., Couch W.
<Mon. Not. R. Astron. Soc. 370, 1223 (2006)>
=2006MNRAS.370.1223B 2006MNRAS.370.1223B
ADC_Keywords: Clusters, galaxy ; Galaxies, nearby ; Radial velocities ;
Velocity dispersion
Keywords: surveys - galaxies: evolution - galaxies: formation -
galaxies: fundamental parameters
Abstract:
Here, we present an investigation of the properties of 15 nearby
galaxy groups and their constituent galaxies. The groups are selected
from the Group Evolution Multiwavelength Study (GEMS) and all have
X-ray as well as wide-field neutral hydrogen (HI) observations. Group
membership is determined using a friends-of-friends algorithm on the
positions and velocities from the 6-degree Field Galaxy Survey and
NASA/IPAC Extragalactic Database. For each group we derive their
physical properties using this membership, including: velocity
dispersions (sigmav), virial masses (MV), total K-band
luminosities [LK(Tot)] and early-type fractions (fearly) and
present these data for the individual groups.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 123 15 Dynamical parameters of groups derived using
FOF (friends-of-friends) membership and distances
tablea1.dat 107 249 Details of the galaxies in each group
--------------------------------------------------------------------------------
See also:
VII/86 : Groups of Galaxies. I. Nearby Groups (Huchra+ 1982)
VII/145 : Nearby Galaxies Catalogue (NBG) (Tully 1988)
VII/161 : Nearby Galaxies (Schmidt+ 1993)
J/A+AS/139/97 : HI properties of nearby galaxies (Karachentsev+, 1999)
J/ApJ/543/178 : Nearby Optical Galaxy (NOG) sample (Giuricin+, 2000)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Group Group name
10- 11 I2 --- Nm Number of members in each group as
defined by the FOF algorithm
13- 14 I2 --- NmK Number of members with MK≤20 (1)
16- 17 I2 h RAh Right ascension (J2000)
19- 20 I2 min RAm Right ascension (J2000)
22- 26 F5.2 s RAs Right ascension (J2000)
28 A1 --- DE- Declination sign (J2000)
29- 30 I2 deg DEd Declination (J2000)
32- 33 I2 arcmin DEm Declination (J2000)
35- 39 F5.2 arcsec DEs Declination (J2000)
41- 44 I4 km/s Mean group velocity
46- 47 I2 km/s e_ sigma/sqrt(N) error on
49- 51 I3 km/s sigma Velocity dispersion
53- 54 I2 km/s e_sigma 1sigma error on sigma
56- 59 F4.2 Mpc r500 r500 radius, calculated from the
velocity dispersion
61- 64 F4.2 Mpc e_r500 1sigma error on r500
66- 68 F3.1 10+13solMass Mvir Virial mass
70- 72 F3.1 10+13solMass e_Mvir 1sigma error on Mvir
74- 77 F4.2 --- tc Crossing time (in units of 1/H0)
79- 83 F5.3 --- e_tc 1sigma error on tc
85- 88 F4.2 10+11solLum LK Total K-band luminosity
90- 93 F4.2 10+11solLum e_LK 1sigma error on LK
95- 97 I3 Sun MV/LK Mass-to-light ratio
99-100 I2 Sun e_MV/LK 1sigma error on MV/LK
102-105 F4.2 --- f(early) Early-type galaxies fraction
107-110 F4.2 --- e_f(early) Poissonian error on f(early)
112-115 F4.2 Mpc Extent Maximum projected radial extent
117-120 F4.1 Mpc Dist Distance used for the dynamical
parameter determination
122-123 A2 --- r_Dist Reference for Dist (2)
--------------------------------------------------------------------------------
Note (1): The magnitude limit of 2MASS at the distance of our furthest group,
NGC 3557.
Note (2): Distances from Tonry et al., 2001ApJ...546..681T 2001ApJ...546..681T, corrected following:
TJ = Jensen et al., 2003ApJ...583..712J 2003ApJ...583..712J
O = Osmond & Ponman, 2004MNRAS.350.1511O 2004MNRAS.350.1511O
F = Forbes et al., 2006, Cat. J/MNRAS/366/1230
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Group Group designation
10- 34 A25 --- Name Galaxy name (1)
36- 38 A3 --- --- [6dF]
40- 54 A15 --- 6dF 6dF designation (JHHMMSSs-DDMMSS)
56- 57 I2 h RAh Right ascension (J2000)
59- 60 I2 min RAm Right ascension (J2000)
62- 66 F5.2 s RAs Right ascension (J2000)
68 A1 --- DE- Declination sign (J2000)
69- 70 I2 deg DEd Declination (J2000)
72- 73 I2 arcmin DEm Declination (J2000)
75- 79 F5.2 arcsec DEs Declination (J2000)
81- 84 I4 km/s Mean velocity
86- 90 F5.2 mag Kmag K magnitude
92- 96 F5.3 mag e_Kmag rms uncertainty on Kmag
98-102 F5.3 Mpc Rgc Group-centric radius from the centre
calculated by the FOF algorithm
104-107 F4.1 --- TType ?=99.9 Morphological T-type
--------------------------------------------------------------------------------
Note (1): New galaxies found in HI are named GEMS-groupname-number.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 13-Nov-2006