Understanding the role of morphology and environment in the dynamical evolution of isolated galaxy triplets

DOI: 
10.1051/0004-6361/202245297
Publication date: 
15/02/2023
Main author: 
Vásquez-Bustos, P.
IAA authors: 
Duarte Puertas, S.
Authors: 
Vásquez-Bustos, P.;Argudo-Fernandez, M.;Grajales-Medina, D.;Duarte Puertas, S.;Verley, S.
Journal: 
Astronomy and Astrophysics
Publication type: 
Article
Volume: 
670
Pages: 
A63
Abstract: 
Context. 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. <BR /> Aims: 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). <BR /> Methods: 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 Q<SUB>trip</SUB> 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 R<SUB>H</SUB>, velocity dispersion σ<SUB>v<SUB>r</SUB></SUB>, crossing time H<SUB>0</SUB>t<SUB>c</SUB>, and virial mass M<SUB>vir</SUB>. <BR /> Results: Triplets composed of three early-type galaxies present the smallest R<SUB>H</SUB>, indicating that they are in general more compact than triplets with one or more late-type galaxies. Among triplets with low values of R<SUB>H</SUB> and H<SUB>0</SUB>t<SUB>c</SUB>, SIT triplets with Q<SUB>trip</SUB> &lt; −2 are relaxed systems that are more dynamically evolved, while triplets with Q<SUB>trip</SUB> &gt; −2 show compact configurations due to interactions within the system, such as ongoing mergers. <BR /> Conclusions: 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'. <P />Full Table 1 is only available at the CDS via anonymous ftp to <A href="http://cdsarc.cds.unistra.fr">cdsarc.cds.unistra.fr</A> (ftp://130.79.128.5) or via <A href="https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/670/A63">https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/670/A63</A>
Database: 
ADS
SCOPUS
URL: 
https://ui.adsabs.harvard.edu/#abs/2023A&A...670A..63V/abstract
ADS Bibcode: 
2023A&A...670A..63V
Keywords: 
galaxies: general;galaxies: evolution;galaxies: formation;galaxies: groups: general;galaxies: interactions