J/MNRAS/357/1337 Hα survey of cluster galaxies (Moss+, 2005)
An Hα survey of cluster galaxies -
V. Cluster-field comparison for early-type galaxies.
Moss C., Whittle M.
<Mon. Not. R. Astron. Soc., 357, 1337-1347 (2005)>
=2005MNRAS.357.1337M 2005MNRAS.357.1337M
ADC_Keywords: Clusters, galaxy ; Photometry, H-alpha ; Radial velocities
Keywords: surveys - galaxies: clusters: general -
galaxies: elliptical and lenticular, cD - galaxies: evolution -
galaxies: interactions - galaxies: starburst
Abstract:
We have extended our Hα objective prism survey of eight
low-redshift clusters (viz. Abell 262, 347, 400, 426, 569, 779, 1367
and 1656) to include a complete sample of early-type galaxies within
1.5 Abell radii of the cluster centres. Of the 379 galaxies surveyed,
3 per cent of E, E-S0 galaxies, 6 per cent of S0 galaxies, and 9 per
cent of S0/a galaxies were detected in emission. From a comparison of
cluster and supercluster field galaxies, we conclude that the
frequency of emission-line galaxies (ELGs; W≥20Å) is similar for
field and cluster early-type galaxies. A similar result has previously
been obtained for galaxies of types Sa and later. Together, these
results confirm the inference of Biviano et al. (1997A&A...321...84B 1997A&A...321...84B)
that the relative frequency of ELGs in clusters and the field can be
entirely accounted for by the different mix of morphological types
between the differing environments, and that, for galaxies of a given
morphological type, the fraction of ELGs is independent of
environment. Detected emission is classified as 'compact' or
'diffuse', identified as circumnuclear starburst or active galactic
nucleus (AGN) emission and disc emission, respectively. By comparing
spectroscopic data for cluster early-type ELGs with data for field
galaxies from the Palomar spectroscopic survey of nearby galactic
nuclei, we demonstrate that there is modest evidence for an
enhancement of compact H II emission relative to AGN emission in the
early-type cluster ELGs as compared to the field. For the cluster
early-type galaxies, compact H II emission correlates strongly with a
disturbed morphology. This suggests that, as for later-type cluster
galaxies, this enhanced compact H II emission can readily be explained
as an enhancement of circumnuclear starburst emission due to
gravitational tidal interactions, most likely caused by subcluster
merging and other on-going processes of cluster virialization.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 41 383 Cluster galaxy survey sample
table2.dat 75 28 Galaxies detected in Hα emission
notes.dat 80 19 Individual notes
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See also:
J/AJ/124/2453 : Spectroscopy of active gal. in nearby clusters (Miller+, 2002)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Cluster Cluster name (Abell NNNN)
12- 18 A7 --- CGCG CGCG number (Z NNN-NNN in Simbad) (1)
19 A1 --- m_CGCG [AB] Multiplicity index on CGCG (G1)
21- 24 I4 --- UGC ?=- UGC number (Nilson 1973, Cat. VII/26)
27- 35 A9 --- MType Galaxy morphological type taken from UGC
or estimated from the Palomar Sky Survey
37- 41 I5 km/s HRV ? Heliocentric velocity taken from the
NASA Extragalactic Database (NED)
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Note (1): Galaxies not surveyed. A total of 24 galaxies were not surveyed
because of plate defects: nine galaxies on a defocused region of plate
15270 for Abell 1656 (CGCG Nos 159-106, 159-114, 159-119, 160-016,
160-029, 160-034, 160-035, 160-044A and 160-044B); 12 galaxies whose
spectra were overlapped by adjacent stellar or galaxy spectra (CGCG
Nos 159-113, 522-027, 538-041, 538-057A, 538-057B, 538-060, 539-043,
415-034, 415-041A, 415-041B, 540-089 and 541-016A); and three galaxies
that lay outside the overlap region of the survey plate pair (CGCG Nos
503-033, 503-040 and 540-035).
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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- 10 A10 --- Cluster Cluster name (Abell NNNN)
12- 18 A7 --- CGCG CGCG number (Z NNN-NNN in Simbad)
19 A1 --- m_CGCG [AB] Multiplicity index on CGCG (G1)
21- 24 I4 --- UGC ?=- UGC number (Nilson 1973, Cat. VII/26)
27- 28 I2 h RAh Right ascension (B1950.0)
30- 33 F4.1 min RAm Right ascension (B1950.0)
35 A1 --- DE- Declination sign (B1950.0)
36- 37 I2 deg DEd Declination (B1950.0)
39- 40 I2 arcmin DEm Declination (B1950.0)
42- 44 F3.1 --- Dist Radial distance in Abell radii of the galaxy
with respect to the cluster centre (1)
46- 49 F4.1 mag pgmag CGCG photographic magnitude.
50 A1 --- f_pgmag [)] ): For double galaxies, magnitude estimates
for individual components obtained by eye
from PSSN
52- 60 A9 --- MType Galaxy morphological type taken from UGC
or estimated from the Palomar Sky Survey
61 A1 --- f_MType [+] +: MType from NED
63- 66 I4 km/s HRV ? Heliocentric velocity taken from the NASA
Extragalactic Database (NED)
68- 69 A2 --- Vis Visibility parameter (2)
72- 73 A2 --- Conc Concentration parameter (3)
75 I1 --- n_CGCG ? Note number, in notes.dat
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Note (1): Adopted positions for the cluster centres and values of the Abell
radii are given in Paper IV, Moss & Whittle, 2000MNRAS.317..667M 2000MNRAS.317..667M.
Note (2): Visibility parameter describing how readily the Hα emission is
seen on the plates according to a five-point scale, as follows:
S = strong
MS = medium strong
M = medium
MW = medium weak
W = weak
Note (3): Concentration parameter describing the spatial distribution of
the emission and contrast with the underlying continuum, on a
five-point scale, as follows:
VD = very diffuse
D = diffuse
N = normal
C = concentrated
VC = very concentrated
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Byte-by-byte Description of file: notes.dat
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Bytes Format Units Label Explanations
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1 I1 --- Note Note number
3- 80 A78 --- Text Text of the note
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Global notes:
Note (G1): Double systems:
CGCG 522-034A and B: N and S components, mp∼14.7 and 15.1
CGCG 415-043A and B: NW and SE components, mp∼16.3 and 16.3
CGCG 541-016A and B: S and N components, mp∼15.8 and 15.8
CGCG 234-088A and B: S and N components, mp∼15.4 and 16.6
CGCG 181-024A and B: NE and SW components, mp∼13.7 and 14.5
CGCG 160-046A and B: N and S components, mp∼15.5 and 15.9
CGCG 160-048A and B: W and E components, mp∼15.9 and 16.2
CGCG 160-061A and B: S and N components, mp∼15.8 and 16.1
CGCG 160-113A and B: W and E components, mp∼16.0 and 16.8
CGCG 160-121A and B: S and N components, mp∼15.3 and 15.7
CGCG 160-164A and B: E and W components, mp∼16.3 and 16.3
CGCG 160-176A and B: W and E components, mp∼13.5 and 15.2
CGCG 160-189A and B: E and W components, mp∼14.0 and 16.5
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History:
From electronic version of the journal
References:
Moss et al., Paper I 1988MNRAS.232..381M 1988MNRAS.232..381M
Moss & Whittle, Paper II 1993ApJ...407L..17M 1993ApJ...407L..17M
Moss et al., Paper III 1998MNRAS.300..205M 1998MNRAS.300..205M
Moss & Whittle, Paper IV 2000MNRAS.317..667M 2000MNRAS.317..667M
(End) Patricia Vannier [CDS] 10-Feb-2006