The character of internal motions in galaxy triplets

Kiseleva, Liudmila; Orlov, V.

doi:10.1093/mnras/260.3.475

Cited by 4 publications

(3 citation statements)

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“…Several authors have performed simulations of triple systems requiring the presence of a primordial massive dark matter halo in order to correctly describe the dynamics of these systems (e.g. Valtonen & Mikkola 1991;Chernin et al 1994;Kiseleva & Orlov 1993;Kiseleva 2000). Nevertheless Aceves (2001) states that the presence of a dark matter halo would not be a strong requirement to describe the dynamical evolution of triplets.…”

Section: Dark Matter In Triple Systemsmentioning

confidence: 99%

Galaxy triplets in Sloan Digital Sky Survey Data Release 7 – III. Analysis of configuration and dynamics

Duplancic

Alonso

Lambas

et al. 2014

Monthly Notices of the Royal Astronomical Society

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We analyse the spatial configuration and the dynamical properties of a sample of 92 galaxy triplets obtained from the SDSS-DR7 (SDSS-triplets) restricted to have members with spectroscopic redshifts in the range 0.01 z 0.14 and absolute r-band luminosities brighter than M r = −20.5. The configuration analysis was performed through Agekyan & Anosova map (AA-map). We estimated dynamical parameters, namely the radius of the system, the velocity dispersion, a dimensionless crossing-time and the virial mass. We compared our results with those obtained for a sample of triplets from the catalogue "Isolated Triplets of Galaxies" (K-triplets) and a sample of Compact Groups. We have also studied a mock catalogue in order to compare real and projected configurations, and to estimate the three dimensional dynamical parameters of the triple systems. We found that the SDSS-triplets prefer alignment configurations while K-triplets present an uniform distribution in the AA-map. From the dynamical analysis we conclude that the SDSS-triplets, K-triplets and Compact Groups present a similar behaviour comprising compact systems with low crossing-time values, with velocity dispersions and virial masses similar to those of low mass loose groups. Moreover, we found that observed and simulated triplets present similar dynamical parameters. We also performed an analysis of the dark matter content of galaxy triplets finding that member galaxies of mock triplets belong to the same dark matter halo, showing a dynamical co-evolution of the system. These results suggest that the configuration and dynamics of triple systems favour galaxy interactions and mergers.

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Section: Dark Matter In Triple Systemsmentioning

confidence: 99%

Galaxy triplets in Sloan Digital Sky Survey Data Release 7 – III. Analysis of configuration and dynamics

Duplancic

Alonso

Lambas

et al. 2014

Monthly Notices of the Royal Astronomical Society

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“…One more indirect piece of evidence may be obtained from the analysis of internal motions of galaxies in triplets. Kiseleva and Orlov (1993a) studied statistically the character of these motions in compact and wide triplets. They found that in the probably physical Karachentsev compact triplets galaxies move isotropically with probability P = 0.93.…”

Section: Dark Matter Configurations and Internal Motions Of Triple Gmentioning

confidence: 99%

The connection between dark matter, internal motions and configurational properties of triple galaxies

Kiseleva¹

2000

International Astronomical Union Colloquium

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Abstract. Numerical simulations of the dynamics of triplets of galaxies show that virial estimations of the individual masses of triplets are unreliable because of strong nonsteadiness of these groups and projection effects. However, the mass of a typical small galaxy group can be estimated statistically, from data on a whole homogeneous ensemble of groups such as, for example, Karachentsev's Catalogue of compact galaxy triplets. The characteristic total mass of a triplet from this catalogue is 4 -7 times greater than the visible mass when the standard mass-to-light ratio is assumed. This suggests the presence of some considerable amount of dark matter even in these compact triplets. In wide triplets of galaxies the amount of dark matter may be significantly larger. The presence of distributed dark matter makes motions of galaxies in triplets more stochastic. In this case the existence of long-lived hierarchical configurations (temporary binaries) in triple systems becomes much less probable than without dark matter. The analysis of internal motions of galaxies in triplets and their configurations may be interpreted as additional non-dynamical evidence of the presence of dark matter in galaxy triplets.

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“…Compact triplets with a mean projected harmonic separation of about 0.04 Mpc (for were the focus of their research, and an extensive data set on the systems was finally presented (Karachentsev, Karachentseva & Lebedev 1989) on the basis of mostly original observations with the 6‐m telescope of the Special Astrophysical Observatory (SAO). These data were discussed by Kiseleva & Chernin (1988), Chernin & Mikkola (1991), Anosova et al (1991, 1992, 1993), Kiseleva & Orlov (1993) and Chernin et al. (1994) from the theoretical viewpoint.…”

Section: Introductionmentioning

confidence: 99%

Wide triplets of galaxies: collapse on spatial scales of ∼1 Mpc

Chernin¹,

Dolgachev²,

Domozhilova³

2002

Monthly Notices of the Royal Astronomical Society

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We study triple systems of galaxies with mean projected harmonic separation ≃0.6 h−1 Mpc We call the systems ‘wide triplets’, in contrast to compact triplets with mean projected harmonic separation ≃0.04 h−1 Mpc, studied by Karachentsev et al. Data are taken for 108 wide triplets from a list compiled by Trofimov & Chernin; at least one‐third of them are considered to be probably isolated physical systems. With typical crossing times of about the Hubble time, the wide triplets seem to be in a state of ongoing collapse. This is confirmed by a set of computer models which simulate well the observational characteristics of the ensemble of wide triplets. The simulations also give a statistical estimate of the total mass of a typical wide triplet: it proves to be ≃1013 M⊙. This figure indicates that the dark matter mass is 15–30 times the mass of baryonic matter in the systems. The dynamics of wide triplets, as well as their dark matter content, provide new direct cosmological constraints by establishing that hierarchical evolution is occurring on a mass scale of ∼1013 M⊙ and a spatial scale of ∼1 Mpc.

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The character of internal motions in galaxy triplets

Cited by 4 publications

References 0 publications

Galaxy triplets in Sloan Digital Sky Survey Data Release 7 – III. Analysis of configuration and dynamics

Galaxy triplets in Sloan Digital Sky Survey Data Release 7 – III. Analysis of configuration and dynamics

The connection between dark matter, internal motions and configurational properties of triple galaxies

Wide triplets of galaxies: collapse on spatial scales of ∼1 Mpc

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