J/ApJ/773/86 Star-forming galaxies in ACO 2029 (Tyler+, 2013)
Star-forming galaxy evolution in nearby rich clusters.
Tyler K.D., Rieke G.H., Bai L.
<Astrophys. J., 773, 86 (2013)>
=2013ApJ...773...86T 2013ApJ...773...86T
ADC_Keywords: Clusters, galaxy ; Redshifts ; Galaxies, spectra ;
Infrared sources ; Ultraviolet
Keywords: galaxies: clusters: individual (A2029, Coma);
galaxies: evolution; galaxies: luminosity function, mass function;
galaxies: photometry; infrared: galaxies
Abstract:
Dense environments are known to quench star formation in galaxies, but
it is still unknown what mechanism(s) are directly responsible. In
this paper, we study the star formation of galaxies in A2029 and
compare it to that of Coma, combining indicators at 24µm, Hα,
and UV down to rates of 0.03M☉/yr. We show that A2029's
star-forming galaxies follow the same mass-SFR relation as the field.
The Coma cluster, on the other hand, has a population of galaxies with
star formation rates (SFRs) significantly lower than the field
mass-SFR relation, indicative of galaxies in the process of being
quenched. Over half of these galaxies also host active galactic
nuclei. Ram-pressure stripping and starvation/strangulation are the
most likely mechanisms for suppressing the star formation in these
galaxies, but we are unable to disentangle which is dominating. The
differences we see between the two clusters' populations of
star-forming galaxies may be related to their accretion histories,
with A2029 having accreted its star-forming galaxies more recently
than Coma. Additionally, many early-type galaxies in A2029 are
detected at 24µm and/or in the far-UV, but this emission is not
directly related to star formation. Similar galaxies have probably
been classified as star forming in previous studies of dense clusters,
possibly obscuring some of the effects of the cluster environment on
true star-forming galaxies.
Description:
Cluster A2029 was originally observed at 24um with the Multiband
Imaging Photometer for Spitzer (MIPS) in 2004 February. Additional
observations in 2005 January to look for faint intracluster emission
extended the exposure time to ∼340s/pixel (Bai et al.
2007ApJ...668L...5B 2007ApJ...668L...5B).
To confirm cluster members spectroscopically, we targeted objects down
to r∼20 in the inner 60' of the MIPS field with the Hectospec fiber
spectrograph on the MMT at Mt. Hopkins (wavelength range of
3650-9200Å at a resolution of 6Å).
We selected far-UV (FUV) sources in the GALEX database from the A2029
pointed observation GI3-103 (PI: Hicks) described in further detail in
Hicks et al. (2010ApJ...719.1844H 2010ApJ...719.1844H).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 72 585 A2029 member list
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See also:
II/312 : GALEX-DR5 (GR5) sources from AIS and MIS (Bianchi+ 2011)
J/ApJ/761/114 : Multi-wavelength study of galaxy clusters II. (Atlee+, 2012)
J/ApJ/714/1256 : Far-IR star formation rate indicators (Calzetti+, 2010)
J/ApJ/707/890 : IR properties of E and S0 galaxies (Temi+, 2009)
J/ApJ/703/1672 : Far-IR and Hα fluxes in galaxies (Kennicutt+, 2009)
J/ApJ/692/556 : Star forming galaxy templates (Rieke+, 2009)
J/ApJ/666/863 : GOODS MIPS early-type galaxies (Van Der Wel+, 2007)
J/MNRAS/357/1337 : Hα survey of cluster galaxies (Moss+, 2005)
J/AJ/126/1607 : IRAS Revised Bright Galaxy Sample (Sanders+, 2003)
J/ApJS/132/37 : Spectroscopy of Southern warm IR galaxies (Kewley+, 2001)
J/ApJ/496/39 : Properties of poor groups of galaxies. I. (Zabludoff+ 1998)
J/MNRAS/292/419 : Cooling flows in 207 clusters of galaxies (White+, 1997)
J/ApJ/252/102 : Radio sources in bright spiral galaxies. II. (Condon+, 1982)
http://www.sdss3.org/ : SDSS-III home page
http://galex.stsci.edu/GR6/ : GALEX GR6/7 home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension in decimal degrees (J2000)
11- 19 F9.7 deg DEdeg Declination in decimal degrees (J2000)
21- 26 F6.4 --- z [0.06/0.09] Redshift
28- 33 F6.3 [Lsun] logL24 [7.8/11.6]?=-9.999 Log 24µm luminosity
35- 40 F6.3 [Lsun] logLHa [5.7/8.5]?=-9.999 Log Hα luminosity
42- 47 F6.3 [Lsun] logLFUV [8/10.3]?=-9.999 Log FUV luminosity
49- 54 F6.3 Msun/yr SFRmin [0.01/10]?=-9.999 Minimum star formation rate (1)
56- 61 F6.3 Msun/yr SFRmax [0.03/10]?=-9.999 Maximum star formation rate (1)
63- 68 F6.3 [Msun] logM* [8.3/11.9]?=-9.999 Log stellar mass
70- 72 A3 --- Notes [0-4,] Additional note(s) (2)
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Note (1): If a galaxy only has Hα or FUV detections (no 24µm), then
the lower limit (min) on SFR is calculated using these wavelengths
without dust corrections. The upper limit (max) is calculated using
our 24µm detection limit with Hα (or FUV if Hα is
not available). If the min and max values of SFR are the same, then
the SFR was calculated using 24µm and Hα (or FUV if
Hα is not available). In these cases, the total SFR includes
both obscured and unobscured components from measured quantities.
Note (2): Note as follows:
0 = indicates galaxies without any 24µm coverage;
1 = indicates galaxies from SDSS or NED;
2 = indicates passive (non-star-forming) galaxies;
3 = indicates galaxies spectroscopically identified as possible
AGN (non-star-forming);
4 = indicates galaxies with shallow 24µm coverage that are not
included in the analysis. Galaxies from SDSS, NED, and with shallow
24µm coverage have not been identified as being passive vs.
star-forming, and most have not been identified as hosting AGN or
not since most do not have Hectospec coverage.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 20-Feb-2015