J/A+A/670/A63 Galaxy triplets (Vasquez-Bustos+, 2023)
Understanding the role of morphology and environment in the dynamical evolution
of isolated galaxy triplets.
Vasquez-Bustos P., Argudo-Fernandez M., Grajales-Medina D.,
Duarte Puertas S., Verley S.
<Astron. Astrophys. 670, A63 (2023)>
=2023A&A...670A..63V 2023A&A...670A..63V (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies ; Morphology ; Velocity dispersion ; Optical
Keywords: galaxies: general - galaxies: evolution - galaxies: formation -
galaxies: groups: general - galaxies: interaction
Abstract:
The environments where galaxies reside affects their evolutionary
histories. Galaxy triplets (systems composed of three physically bound
galaxies) are one of simplest groups of galaxies, and are therefore
excellent laboratories to study evolutionary mechanisms where effects
of the environment are minimal.
We present a statistical study of the dynamical properties of isolated
galaxy triplets as a function of their local and large-scale
environments. To explore the connection of the dynamical evolution on
the systems with the evolution of the galaxies composing the triplets,
we consider observational properties such as morphology and star
formation rate (SFR).
We used the SDSS-based catalogue of Isolated Triplets (SIT), which
contains 315 triplets. We classified each triplet according to galaxy
morphologies and defined a parameter Qtrip to quantify the total local
tidal strengths in the systems. To quantify the dynamical stage of the
system we used the parameters of harmonic radius RH , velocity
dispersion σvr, crossing time H0tc, and virial mass
Mvir.
Triplets composed of three early-type galaxies present the smallest
RH, indicating that they are in general more compact than triplets
with one or more late-type galaxies. Among triplets with low values of
RH and H0tc, SIT triplets with Qtrip←2 are relaxed systems
that are more dynamically evolved, while triplets with Qtrip>-2 show
compact configurations due to interactions within the system, such as
ongoing mergers.
We found that there is no dominant galaxy in triplets in terms of
properties of stellar populations such as global colour and SFR.
Moreover, the global SFR in isolated triplets composed of two or more
early-type galaxies increases with the stellar mass ratio of the
galaxies with respect to the central galaxy, therefore the system is
globally 'rejuvenated'.
Description:
Dynamical parameters (harmonic radius, velocity dispersion, crossing
time, and virial mass), total local tidal strength (Qtrip), and
morphology categories for the 315 triplets in the SIT.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 55 315 Dynamical parameters, tidal strength, and
morphology for SIT triplets
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See also:
J/A+A/578/A110 : Isolated galaxies, pairs and triplets (Argudo-Fernandez+ 2015)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- SIT [1/315] Isolated triplet identification
5- 12 F8.4 deg RAdeg Right ascension (J2000.0)
14- 20 F7.4 deg DEdeg Declination (J2000.0)
22- 26 F5.2 --- Qtrip Tidal strength estimation of the triplet due
to member galaxies
28- 33 F6.2 kpc RH Harmonic radius
35- 40 F6.2 km/s Sigma Velocity dispersion
42- 45 F4.2 --- H0tc Crossing time
47- 51 F5.2 [Msun] log(Mvir) Virial mass
53- 55 A3 --- Cat Morphology classification of the isolated
triplet (1)
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Note (1): Morphology classification as follows:
TCE = triplets with three late-type galaxies
TCL = triplets with three early-type galaxies
TE = triplets with the central galaxy a late-type
TL = triplets with the central galaxy an early-type
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Acknowledgements:
Paup Vasquez Bustos, paulo.vasquez.b(at)mail.pucv.cl
(End) Paulo Vasquez [PUCV, Chile], Patricia Vannier [CDS] 12-Dec-2022