J/A+A/662/A84 MS 0451.6-0305 ram pressure stripping galaxies (Durret+, 2022)
Ram pressure stripping in the z∼0.5 galaxy cluster MS 0451.6-0305.
Durret F., Degott L., Lobo C., Ebeling H., Jauzac M., Tam S.-I.
<Astron. Astrophys. 662, A84 (2022)>
=2022A&A...662A..84D 2022A&A...662A..84D (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Redshifts ; Photometry, infrared
Keywords: galaxies: clusters: individual: MS 0451.6-0305 -
galaxies: photometry - galaxies: peculiar
Abstract:
The pressure exerted by the ambient hot X-ray gas on cluster galaxies
can lead to the presence of ram pressure stripped (RPS) galaxies,
characterized by asymmetric shapes, and, in some cases, tails of blue
stars and/or X-ray gas, with increased star formation.
With the aim of increasing the known sample of RPS galaxies at
redshift z∼0.5, notably higher than most RPS samples presently known,
we extended our searches for such galaxies to the cluster MS
0451.6-0305.
Our study is based on Hubble Space Telescope (HST) imaging in the
F814W band (corresponding to a restframe wavelength of 529nm),
covering a region of about 6x6Mpc2, an eight magnitude ground-based
catalogue with photometric redshifts, and a spectroscopic redshift
catalogue. We defined as cluster members a spectroscopic redshift
sample of 359 galaxies within ±4σv of the mean cluster
velocity, and a photometric redshift sample covering the [0.48,0.61]
range. We searched for RPS galaxies in the HST images and tested the
error on their classification with a Zooniverse collaboration. We also
computed the phase space diagram of RPS candidates in the
spectroscopic sample. Finally, we ran the LePhare stellar population
synthesis code through the GAZPAR interface to analyze and compare the
properties of RPS and non-RPS galaxies.
We find 56 and 273 RPS candidates in the spectroscopic and photometric
redshift samples, respectively. They are distributed throughout the
cluster and tend to avoid high density regions. The phase space
diagram gives the percentages of virialized, backsplash, and infall
galaxies. RPS galaxy candidates typically show rather high star
formation rates, young ages, and relatively low masses. We compare all
our results to those previously obtained for the massive merging
cluster MACS J0717+3745, at a similar redshift.
This study increases by at least 56 objects if we only consider
galaxies with spectroscopic redshifts, and probably much more if
galaxies with photometric redshifts are taken into account. This study
increases the number of RPS candidates at redshift z>0.5, and
confirms that they host, on average, younger stellar populations and
strongly form stars when compared with non-RPS counterparts. The fact
that RPS candidates with spectroscopic and with photometric redshifts
have comparable properties shows that large samples of such objects
could be gathered based on multi-band photometry only, a promising
result in view of the very large imaging surveys planned in the coming
years (DES, Euclid, LSST, etc.).
Description:
Our study is based on a large HST/ACS mosaic in the F814W filter
covering a region of about 6x6Mpc2 at the cluster redshift,
collected for the programmes GO-09836, -10493, and -11591. We
also examined F555W imaging from a single ACS pointing obtained for
GO-09722 but found the covered area too small to be significant for
the purpose of this work.
Objects:
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RA (2000) DE Designation(s)
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04 54 10.9 -03 01 07 MS 0451.6-0305 = ClG 0451-03
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 57 217 Ram pressure stripping (RPS) galaxy candidates
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See also:
J/A+A/631/A114 : Ram pressure in cluster galaxies a z=0.7 (Boselli+, 2019)
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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2- 4 I3 --- Seq Running number
9- 16 F8.5 deg RAdeg Right ascension (J2000.0)
20- 27 F8.5 deg DEdeg Declination (J2000.0)
31- 36 F6.4 --- z Photometric redshift
40 I1 --- Class [1/5] J classification (according to
Poggianti et al., 2016AJ....151...78P 2016AJ....151...78P,
Cat. J/AJ/151/78) (1)
44- 49 F6.3 mag F814W F814W magnitude
53- 57 F5.3 mag e_F814W Error on F814W magnitude
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Note (1): Ranges from 5 (strongest) to 1 (weakest).
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Acknowledgements:
Florence Durret, durret(at)iap.fr
(End) Patricia Vannier [CDS] 14-Apr-2022