J/ApJ/518/69 Deep Optical Catalog of galaxy systems (Mahdavi+, 1999)
The dynamics of poor systems of galaxies.
Mahdavi A., Geller M.J., Bohringer H., Kurtz M.J., Ramella M.
<Astrophys. J. 518, 69 (1999)>
=1999ApJ...518...69M 1999ApJ...518...69M
ADC_Keywords: Clusters, galaxy ; Redshifts
Keywords: galaxies: clusters: general - galaxies: fundamental parameters -
X-rays: galaxies
Abstract:
We assemble and observe a sample of poor galaxy systems that is
suitable for testing N-body simulations of hierarchical clustering and
other dynamical halo models. We (1) determine the parameters of the
density profile Ρ(r) and the velocity dispersion profile
σp(R), (2) separate emission-line galaxies from
absorption-line galaxies, examining the model parameters, β, and
as a function of spectroscopic type, and (3) for the best-behaved
subsample, constrain the velocity anisotropy parameter, β, which
determines the shapes of the galaxy orbits. Our sample consists of 20
systems, 12 of which have extended X-ray emission in the ROSAT All-Sky
Survey. We measure the 877 optical spectra of galaxies brighter than
mR∼15.4 within 1.5h-1Mpc of the system centers (we take
H0=100h*km/s/Mpc). Thus, we sample the system membership to a radius
typically three times larger than other recent optical group surveys.
The average system population is 30 galaxies, and the average
line-of-sight velocity dispersion is ∼300km/s. The Navarro, Frenk, &
White universal profile and the Hernquist model both provide good
descriptions of the spatial data. In most cases an isothermal sphere
is ruled out. Systems with declining σp(R) are well-matched by
theoretical profiles in which the star-forming galaxies have
predominantly radial orbits (β>0); many of these galaxies are
probably falling in for the first time. There is significant evidence
for spatial segregation of the spectroscopic classes regardless of
σp(R).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 79 20 The Deep Optical Catalog: basic data
table2.dat 45 877 Galaxy positions and measured velocities
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See also:
VII/193 : The CfA Redshift Catalogue, Version June 1995 (Huchra+ 1995)
J/AJ/116/1 : Southern Sky Redshift Survey (SSRS2) (Da Costa+, 1998)
J/ApJ/534/114 : RASSCALS: X-ray and optical study (Mahdavi+, 2000)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- DOC Group identification (Deep Optical Catalog)
(, in Simbad)
8- 9 A2 --- n_DOC [abcde ] Individual Notes (1)
11- 12 I2 h RAh Right ascension (J2000)
14- 15 I2 min RAm Right ascension (J2000)
17- 20 F4.1 s RAs Right ascension (J2000)
22 A1 --- DE- Declination sign (J2000)
23- 24 I2 deg DEd Declination (J2000)
26- 27 I2 arcmin DEm Declination (J2000)
29- 30 I2 arcsec DEs Declination (J2000)
32- 33 I2 --- NCSOC Number of galaxies classified as members in the
CSOC (combined CfA-SSRS2 redshifts surveys,
Ramella et al., 1999, in prep.)
35- 36 I2 --- Ntot Total number of galaxies to mR∼15.4
in the field of the system
38- 39 I2 --- Ndoc Total number of galaxies classified as members
in this work.
41- 45 I5 km/s Recession velocity of the system
47- 48 I2 km/s E_ Error in (upper limit)
50- 51 I2 km/s e_ Error in (lower limit)
53- 55 I3 km/s sigmap Dispersion velocity
57- 58 I2 km/s E_sigmap Error in sigmap (upper limit)
60- 61 I2 km/s e_sigmap Error in sigmap (lower limit)
63- 66 A4 --- Com Comments (2)
68 A1 --- l_Ppoint Limit flag on Ppoint
69- 73 F5.3 % Ppoint ? Probability that the X-ray emission in the
field is due to a single point source.
74 A1 --- --- [/]
75- 79 F5.3 % Ppoint2 ? Probability for NRGs156. See note (3)
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Note (1): the footnotes have the following meaning:
a = Also studied by Zabludoff & Mulchaey (1998, Cat. J/ApJ/496/39)
b = Also studied by Ramella et al. (1995, J/AJ/109/1458)
c = Contains Hickson Compact Group 37 (Hickson 1982, Cat. VII/213)
d = Abell 779 (Abell, 1958, Cat. VII/4)
e = Abell 1185 (Abell, 1958, Cat. VII/4)
Note (2): the symbols used have the following meaning:
X = has X-ray emission
XC = position quoted is the X-ray centroid
OC = position quoted is the mean optical position
Note (3): Probabilities for the south (Ppoint) and the north (Ppoint2)
X-ray emission peaks coincident with member galaxies.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- DOC Group identification (SNGaNNN or NRGaNNN)
8- 10 A3 --- m_DOC Galaxy number in the Group (.NN)
(, in simbad)
12- 13 I2 h RAh Right ascension (J2000)
15- 16 I2 min RAm Right ascension (J2000)
18- 21 F4.1 s RAs Right ascension (J2000)
23 A1 --- DE- Declinatio sign (2000)
24- 25 I2 deg DEd Declination (J2000)
27- 28 I2 arcmin DEm Declination (J2000)
30- 31 I2 arcsec DEs Declination (J2000)
33- 37 I5 km/s cz Velocity (typical uncertainty = 40km/s)
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History: From ApJ electronic version
(End) James Marcout, Patricia Bauer [CDS] 14-Sep-1999