J/A+A/631/A87 Close pairs of galaxies in MUSE Deep Fields (Ventou+, 2019)
New criteria for the selection of galaxy close pairs from cosmological
simulations:
evolution of the major and minor merger fraction in MUSE deep fields.
Ventou E., Contini T., Bouche N., Epinat E., Brinchmann J., Inami H.,
Richard J., Schroetter I., Soucail G., Steinmetz M., Weilbacher P.
<Astron. Astrophys. 631, A87 (2019)>
=2019A&A...631A..87V 2019A&A...631A..87V (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra ; Redshifts ; Surveys ; Spectroscopy
Keywords: galaxies: evolution - galaxies: high-redshift - galaxies: interactions
Abstract:
Using the ILLUSTRIS cosmological simulation project, we investigate
the relation between the separation of galaxies in a pair, both in
velocity and projected spatial separation space, and the probability
that these interacting galaxies will merge in the future. From this
analysis, we propose a new set of criteria to select close pairs of
galaxies along with a new corrective term to be applied to the
computation of the galaxy merger fraction. We then probe the evolution
of the major and minor merger fraction using the latest MUSE deep
observations over the Hubble Ultra Deep Field, Hubble Deep Field
South, COSMOS-Gr30 and Abell 2744 regions. From a parent sample of
2483 galaxies with spectroscopic redshifts, we identify 366 close
pairs spread over a large range of redshifts (0.2<z<6) and stellar
masses (107-1011M☉). Using the stellar mass ratio between
the secondary and primary galaxy as a proxy to split the sample into
major, minor and very minor mergers, we found a total of 183 major,
142 minor and 47 very minor close pairs corresponding to a mass ratio
range of 1:1-1:6, 1:6-1:100 and lower than 1:100, respectively. Due to
completeness issues, we do not consider the very minor pairs in the
analysis. Overall, the major merger fraction increases up to z∼2-3
reaching 25% for pairs with the most massive galaxy with a stellar
mass M*>109.5M☉. Beyond this redshift, the fraction decreases
down to ∼5% at z∼6. The major merger fraction for lower mass primary
galaxies M*<109.5M☉, seems to follow a more constant
evolutionary trend with redshift. Thanks to the addition of new MUSE
fields and new selection criteria, the increased statistics of the
pair samples allow to narrow significantly the error bars compared to
our previous analysis (Ventou et al., 2017A&A...608A...9V 2017A&A...608A...9V). The
evolution of the minor merger fraction is roughly constant with cosmic
time, with a fraction of 20% at z<3 and a slow decrease between 3<z<6
to 8-13%.
Description:
Catalogs of close pairs of galaxies detected in the following MUSE
Deep Fields: Hubble Ultra Deep Field (HUDF), Hubble Deep Field South
(HDFS), COSMOS-GR30, and Abell 2744. Two tables are available
containing 183(142) major(minor) close pairs corresponding to a galaxy
mass ratio range of 1:1-1:6(1:6-1:100). For each pair of galaxies, we
give their identification number in the MUSE-based catalog, their
spectroscopic redshift, their stellar mass in logarithmic units, the
projected separation (in kpc) and velocity difference (in km/s)
between the two galaxies in the pair, and the sky region observed with
MUSE: UDF-Mosaic, HDFS, COSMOS-Gr30 and A2744.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
major.dat 123 179 Major close pairs of galaxies (table B3)
minor.dat 123 140 Minor close pairs of galaxies (table B4)
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See also:
J/A+A/575/A75 : MUSE 3D view of HDF-S (Bacon+, 2015)
J/A+A/608/A2 : MUSE Hubble Ultra Deep Field Survey. II. (Inami+, 2017)
J/MNRAS/473/663 : MUSE and HFFs Photometry of A2744 (Mahler+, 2018)
Byte-by-byte Description of file: major.dat minor.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ID1 MUSE Identification number of the
first galaxy in the pair
7- 18 F12.8 deg RA1deg First galaxy right ascension (J2000)
20- 37 F18.14 deg DE1deg First galaxy declination (J2000)
39- 43 F5.3 --- z1 MUSE spectroscopic redshift of the
first galaxy in the pair
45- 48 F4.1 [Msun] logM1 Stellar mass (in log) of the
first galaxy in the pair
50- 54 A5 --- ID2 MUSE Identification number of the
second galaxy in the pair
56- 73 F18.14 deg RA2deg Second galaxy right ascension (J2000)
75- 92 F18.14 deg DE2deg Second galaxy declination (J2000)
94- 98 F5.3 --- z2 MUSE spectroscopic redshift of the
second galaxy in the pair
100-103 F4.1 [Msun] logM2 Stellar mass (in log) of the
second galaxy in the pair
105-108 F4.1 kpc rp Projected separation between the
two galaxies in the pair
110-112 I3 km/s Dv Velocity difference between the
two galaxies in the pair
114-123 A10 --- Field Sky observed with MUSE (1)
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Note (1): Sky observed with MUSE as follows:
UDF-Mosaic = Bacon et al., 2017A&A...608A...1B 2017A&A...608A...1B and
Inami et al., 2017, Cat. J/A+A/608/A2, [IBB2017] NNNN in Simbad
HDFS = Bacon et al., 2015, Cat. J/A+A/575/A75, [BBR2015] NNN in Simbad
COSMOS-Gr30 = Epinat et al. 2018A&A...609A..40E 2018A&A...609A..40E
A2744 = Mahler et al. 2018, Cat. J/MNRAS/473/663
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Acknowledgements:
Thierry Contini, Thierry.Contini(at)irap.omp.eu
(End) Thierry Contini [IRAP, France], Patricia Vannier [CDS] 12-Sep-2019