J/MNRAS/509/5382 Study of EDisCS galaxy clusters (Cooper+, 2022)
H α-based star formation rates in and around z ∼ 0.5 EDisCS clusters.
Cooper J.R., Rudnick G.H., Brammer G.G., Desjardins T., Mann J.L.,
Weiner B.J., Aragon-Salamanca A., De Lucia G., Desai V., Finn R.A.,
Jablonka P., Jaffe Y.L., Moustakas J., Sperone-Longin D., Teplitz H.I.,
Vulcani B., Zaritsky D.
<Mon. Not. R. Astron. Soc. 509, 5382-5398>
=2022MNRAS.509.5382C 2022MNRAS.509.5382C (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies ; Balmer lines ; Infrared ; Optical ;
Ultraviolet ; Spectroscopy ; Photometry ; Star Forming Region ;
Colors
Keywords: galaxies: clusters: general - galaxies: evolution -
galaxies: star formation
Abstract:
We investigate the role of environment on star formation rates (SFRs)
of galaxies at various cosmic densities in well-studied clusters. We
present the star-forming main sequence for 163 galaxies in four EDisCS
clusters in the range 0.4 < z < 0.7. We use Hubble Space
Telescope/Wide Field Camera 3 observations of the Hα emission
line to span three distinct local environments: the cluster core,
infall region, and external field galaxies. The main sequence defined
from our observations is consistent with other published Hα
distributions at similar redshifts but differs from those derived from
star formation tracers such as 24 µm. We find that the
Hα-derived SFRs for the 67 galaxies with stellar masses
greater than the mass-completeness limit of M* > 109.75 M☉ show
little dependence on environment. At face value, the similarities in
the SFR distributions in the three environments may indicate that the
process of finally shutting down star formation is rapid, however, the
depth of our data and size of our sample make it difficult to
conclusively test this scenario. Despite having significant Hα
emission, 21 galaxies are classified as UVJ-quiescent and may
represent a demonstration of the quenching of star formation caught in
the act.
Description:
At z ~> 0.5, the H α line is located at λobs > 1 µm
which is difficult to observe from the ground. The Hubble Space
Telescope (HST) provides access to H α through slitless
spectroscopy using The Wide Field Camera 3 (WFC3). The 3DHST survey
(van Dokkum et al. 2011ApJ...743L..15V 2011ApJ...743L..15V; Momcheva et al.
2016ApJS..225...27M 2016ApJS..225...27M, Cat. J/ApJS/225/27) demonstrated the power of
this mode by observing more than 100000 galaxies in the CANDELS
fields.
This study aims to characterize the distribution of SFRs in galaxies
in the infall and core regions of four z ∼ 0.5 clusters, and to
compare them to a consistently measured field sample. We seek to
quantify how SFRs are affected during a galaxy's journey into the
cluster environment, (i.e see section Introduction).
Our methodology is based on the ESO Distant Cluster Survey (EDisCS;
White et al. 2005A&A...444..365W 2005A&A...444..365W, Cat. J/A+A/444/365) is an ESO Large
Program derived from the optically brightest objects of the Las
Campanas Distant Cluster Survey (Gonzalez et al. 2001ApJS..137..117G 2001ApJS..137..117G,
Cat. J/ApJS/137/117) and comprises 20 clusters within 0.4 < z < 0.8,
(i.e see sections 2.1.1 Cluster core, 2.2 Field sample and 2.1.2
Wide-field follow-up surveys for more details). For the purpose of
this study, we decide to separate our galaxies into three distinct,
but broadly defined, environments, the cluster core, within virial
radius, the infall region which corresponds to all galaxies at the
cluster redshift but beyond the virial radius and the field which
corresponds to foreground and background galaxies.
As explained in the dedicated section 2.3 HST/WFC3 observations, we
obtained HST/Wide Field Camera 3 F105W imaging and G102 grism
spectroscopy in a Cycle 20 program for four EDisCS clusters at z ∼ 0.5
to target star-forming H α emitters. The WFC3 camera captures
both an IR 1.05 µm direct image (F105W) and the spectrum as a
dispersed image for each object in the FOV (G102 grism). The 2D
spectra are the streaks, which represent the flux of each object as it
is spread out over the range (0.7-1.1 µm) of the grism. We extract
spectroscopy data and physical properties from GRIZLI algorithm
processing of WFC3 data.
Next, we compute (in section 2.5 H α line extraction and
redshift prior and 2.6 Stellar masses and star formation rate
corrections) H α fluxes, the stellar masses and SFRHα
for our three galaxy groups. We analyse and details these results in
tables tablee1-3.dat (i.e see also the section 3.1 Galaxy sample
properties and 3.2 Stellar mass-SFR relations).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablee1.dat 95 79 Properties of our core galaxy sample
tablee2.dat 95 28 Properties of out infalling galaxy sample
tablee3.dat 85 116 Properties of our field galaxy sample
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See also:
J/ApJS/225/27 : 3D-HST Survey: grism spectra master catalog (Momcheva+, 2016)
J/A+A/444/365 : ESO Distant Cluster Survey, EDisCS (White+, 2005)
J/ApJS/137/117 : Las Campanas Distant Cluster Survey (LCDCS) (Gonzales+, 2001)
J/ApJ/655/51 : HDFS IRAC observations of 2<z<3.5 galaxies (Wuyts+, 2007)
Byte-by-byte Description of file: tablee1.dat tablee2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- ID GRIZLI object ID (ObjectID) (G1)
18 A1 --- f_ID [b] Flag for galaxies with
S/NHα < 3
20- 27 F8.4 deg RAdeg Right ascension (J2000) (RADeg)
29- 36 F8.4 deg DEdeg Declination (J2000) (DecDeg)
38- 43 F6.4 --- z Spectroscopic redshift (z)
45- 50 F6.3 Mpc D Cluster centric distance (Distance)
52- 56 F5.2 [Msun] log(M*) Stellar mass (StellarMass) (G2)
58- 62 F5.2 10-23W/cm2 FHa Uncorrected Hα flux in cgs units
and S/NHα < 3 detections are listed
at the 3σ upper limit
(fluxHα)
64- 69 F6.3 10-23W/cm2 e_FHa ?=- Mean uncertainty of FHa
(errfluxHα)
71- 75 F5.2 Msun/yr SFRHa Star formation rate and S/N < 3
detections are listed at the 3σ upper
limit (SFR{Halpha}) (G3)
77- 80 F4.2 Msun/yr e_SFRHa ?=- Mean uncertainty of SFRHa
(errSFR{Halpha})
82- 86 F5.2 mag U-V Rest frame U-V colour in AB systems
(U-V) (G4)
88- 92 F5.2 mag V-J Rest frame V-J colour in AB systems
(V-J) (G4)
94- 95 A2 --- UVJ [sf/q] Galaxy classification UVJ
(UVJClassification) (G5)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablee3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- ID GRIZLI object ID (ObjectID) (G1)
18 A1 --- f_ID [b] Flag for galaxies with
S/NHα < 3
20- 27 F8.4 deg RAdeg Right ascension (J2000) (RADeg)
29- 36 F8.4 deg DEdeg Declination (J2000) (DecDeg)
38- 43 F6.4 --- z Spectroscopic redshift (z)
45- 49 F5.2 [Msun] log(M*) Stellar mass (StellarMass) (G2)
51- 55 F5.2 10-23W/cm2 FHa Uncorrected Hα flux in cgs units
and S/NHα < 3 detections are listed
at the 3σ upper limit
(fluxHα)
57- 60 F4.2 10-23W/cm2 e_FHa ?=- Mean uncertainty of FHa
(errfluxHα)
62- 66 F5.2 Msun/yr SFRHa Star formation rate and S/N < 3
detections are listed at the 3σ upper
limit (SFR{Halpha}) (G3)
68- 71 F4.2 Msun/yr e_SFRHa ?=- Mean uncertainty of SFRHa
(errSFR{Halpha})
73- 76 F4.2 mag U-V Rest frame U-V colour in AB systems
(U-V) (G4)
78- 82 F5.2 mag V-J Rest frame V-J colour in AB systems
(V-J) (G4)
84- 85 A2 --- UVJ [sf/q] Galaxy classification UVJ
(UVJClassification) (G5)
--------------------------------------------------------------------------------
Global notes:
Note (G1): GRIZLI (grism redshift and line analysis software for space-based
slitless spectroscopy, https://github.com/gbrammer/grizli) is a
reduction and extraction pipeline in python that allows for
end-to-end processing of WFC3 data, starting from a query of the
ESA Hubble Science archive to download all of the data associated
with an observation ID (i.e section 2.4 Data reduction).
Note (G2): As showed in the equation 2 in the section 2.6 Stellar masses
and star formation rate corrections.
Note (G3): As explained in the section 2.6 Stellar masses and star formation
rate corrections, the SFRHα can be express as the equation 4.
Note (G4): As described in Just et al. (2019), we derived rest-frame U-V and V-J
colours for all of our galaxies (i.e section 2.1.2 Wide-field
follow-up surveys and appendix A).
Note (G5): As explained in the section 2.1.2, we have reliable UVJ colours
that can be used to separate galaxies into quiescent (q) and
star-forming (sf) (e.g. Wuyts et al. 2007ApJ...655...51W 2007ApJ...655...51W,
Cat. J/ApJ/655/51; Williams et al. 2009ApJ...691.1879W 2009ApJ...691.1879W).
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History:
From electronic version of the journal
(End) Luc Trabelsi [CDS] 09-Oct-2024