This study presents the mass distribution for a sample of 18 late-type galaxies in nine Hickson Compact Groups. We used rotation curves from high resolution 2D velocity fields of Fabry-Perot observations and J-band photometry from the 2MASS survey, in order to determine the dark halo and the visible matter distributions. The study compares two halo density profile, an isothermal core-like distribution and a cuspy one. We also compare their visible and dark matter distributions with those of galaxies belonging to cluster and field galaxies coming from two samples: 40 cluster galaxies of Barnes et al (2004) and 35 field galaxies of Spano et al. (2008). The central halo surface density is found to be constant with respect to the total absolute magnitude similar to what is found for the isolated galaxies. This suggests that the halo density is independent to galaxy type and environment. We have found that core-like density profiles fit better the rotation curves than cuspy-like ones. No major differences have been found between field, cluster and compact group galaxies with respect to their dark halo density profiles.
According to the standard model of cosmology the visible, baryonic matter of galaxies is embedded in dark matter haloes, thus extending the mass and the size of galaxies by one to two orders of magnitude. Taking into account dynamical friction between the dark matter haloes, the nearby located M81 group of galaxies as well as the Hickson compact groups of galaxies are here investigated with regard to their dynamical behaviour. The results of the employment of the Markov Chain Monte Carlo method and the genetic algorithm show statistically substantial merger rates between galaxies, and long liv…
We present the galaxy luminosity functions (LFs) of four Hickson Compact Groups using image data from the Subaru Hyper Suprime-Cam. A distinct dip appeared in the faint-ends of all the LFs at $M_g\sim-12$. A similar dip was observed in the LFs of the galaxy clusters Coma and Centaurus. However, LFs in the Virgo, Hydra, and the field had flatter slopes and no dips. As the relative velocities among galaxies are lower in compact groups than in clusters, the effect of galaxy-galaxy interactions would be more significant in compact groups. The $M_g\sim-12$ dip of compact groups may imply that frequ…
Many catalogues of isolated compact groups of galaxies (CGs) have been extracted using Hickson's criteria to identify isolated, dense systems of galaxies, with at least three or four galaxies concordant in magnitude and redshift. But is not clear to what extent the catalogues of CGs are complete and reliable, relative to 3D truly isolated, dense groups. Using five different semi-analytical models of galaxy formation (SAMs), we identify isolated dense groups in 3D real space, containing at least three galaxies. We then build mock redshift space galaxy catalogues and run a Hickson-like CG finder…
Compact groups of galaxies are devised as extreme environments where interactions may drive galaxy evolution. In this work, we analysed whether the luminosities of galaxies inhabiting compact groups differ from those of galaxies in loose galaxy groups. We computed the luminosity functions of galaxy populations inhabiting a new sample of 1412 Hickson-like compact groups of galaxies identified in the Sloan Digital Sky Survey Data Release 16. We observed a characteristic absolute magnitude for galaxies in compact groups brighter than that observed in the field or loose galaxy systems. We also obs…
Near- to Far-Infrared Spectral Energy Distribution Analysis of Interacting Galaxies in Hickson Compact Groups 56 and Stephan's Quintet (HCG 92)
The University of Tokyo（东京大学）；Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM（巴黎萨克雷大学、巴黎西岱大学、法国原子能与替代能源委员会、法国国家科学研究中心、天体物理信息与建模实验室）；QunaSys Europe（QunaSys欧洲公司）
Compact groups have high galaxy densities and low velocity dispersions, and their group members have experienced numerous and frequent interactions during their lifetimes. They provide a unique environment to study the evolution of galaxies. We examined the galaxies types and HI contents in groups to make a study on the galaxy evolution in compact groups. We used the group crossing time as an age indicator for galaxy groups. Our sample is derived from the Hickson Compact Group catalog. We obtained group morphology data from the Hyper-Leda database and the IR classification based on Wide-Field …
Eye of the beholder: Observer reference frame bias in Hickson-like compact groups of galaxies
Universidad Nacional de Córdoba (UNC)（科尔多瓦国立大学）；Observatorio Astronómico de Córdoba (OAC)（科尔多瓦天文台）；CONICET（阿根廷国家科学研究委员会）；Instituto de Astronomía Teórica y Experimental (IATE)（理论与实验天文学研究所）
Although Compact Groups of galaxies (CGs) have been envisioned as isolated extremely dense structures in the Universe, it is accepted today that many of them could be not as isolated as thought. In this work, we study Hickson-like CGs identified in the Sloan Digital Sky Survey Data Release 16 to analyse these systems and their galaxies when embedded in different cosmological structures. To achieve this goal, we identify several cosmological structures where CGs can reside: Nodes of filaments, Loose Groups, Filaments and cosmic Voids. Our results indicate that 45 per cent of CGs do not reside i…
The physics regulating star formation (SF) in Hickson Compact Groups (HCG) has thus far been difficult to describe, due to their unique kinematic properties. In this study we expand upon previous works to devise a more physically meaningful SF relation able to better encompass the physics of these unique systems. We combine CO(1--0) data from the Combined Array from Research in Millimeter Astronomy (CARMA) to trace the column density of molecular gas $Σ_\mathrm{gas}$ and deep H$α$ imaging taken on the Southern Astrophysical Research (SOAR) Telescope tracing $Σ_\mathrm{SFR}$ to investigate star…
In this work, archive 1.4 and 4.86 GHz radio continuum data from the VLA were re-reduced and, together with the 1.4 GHz maps from the NVSS, investigated for the presence of a detectable, non-thermal continuum radio emission that could be associated with the TDG candidates in HCG 26, 91, and 96. Radio emission highly coincident with the optical and $\rm H_α$ emission maxima of the TDG candidate HCG 91i (estimated physical separation of less than 150 pc) was revealed. Should this emission be intrinsic to this object, it would imply the presence of a magnetic field as strong as 11--16 $μ$G -- com…
Hickson Compact Groups (HCGs) are dense configurations of 4 to 10 galaxies, whose HI (neutral gas) morphology appears to follow an evolutionary sequence of three phases, with gas initially confined to galaxies, then significant amounts spread throughout the intra-group medium, and finally with almost no gas remaining in the galaxies themselves. The HI deficiency of HCGs is expected to increase as the HI morphological phase progresses along this sequence, potentially making it a useful proxy for evolutionary phase. We test this hypothesis for the first time with a large sample of 38 HCGs with V…
Megaparsec-Scale Neutral Hydrogen Flows in the Neighborhood of Hickson Compact Group 100
Università degli Studi di Firenze（佛罗伦萨大学）；INAF - Osservatorio Astrofisico di Arcetri（意大利国家天体物理研究所阿切特里天文台）；Xiamen University（厦门大学）；Chinese Academy of Sciences South America Center for Astronomy, National Astronomical Observatories, CAS（中国科学院南美天文中心，国家天文台，中国科学院）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）
We use the outputs of a semi-analytical model of galaxy formation run on the Millennium Simulation to investigate the prevalence of 3D compact groups (CGs) of galaxies from $z = 11$ to 0. Our publicly available code identifies CGs using the 3D galaxy number density, the mass ratio of secondary+tertiary to the primary member, mass density in a surrounding shell, the relative velocities of candidate CG members, and a minimum CG membership of three. We adopt "default" values for the first three criteria, representing the observed population of Hickson CGs at $z = 0$. The percentage of non-dwarf g…
X-ray Characterization of Galaxy Groups and Hickson Groups in COSMOS-Web to z~3.8 I. X-ray Luminosity Function Evolution
Aalto University（阿尔托大学）；University of Helsinki（赫尔辛基大学）；Deutsches Zentrum für Astrophysik（德国天体物理中心）；TU Dresden（德累斯顿工业大学）；DESY（德国电子同步辐射实验室）；Durham University（杜伦大学）；Institute for Advanced Studies in Basic Sciences (IASBS)（基础科学高等研究院）；The University of Texas at Austin（德克萨斯大学奥斯汀分校）；Aix Marseille Univ（艾克斯-马赛大学）；CNRS（法国国家科学研究中心）；University of Victoria（维多利亚大学）
The vast majority of stars in galaxy groups are contained within their constituent galaxies. Some small fraction of stars is expected, however, to follow the global dark matter potential of the group. In compact groups, interactions between the galaxies should be frequent. This leads to a more intensive material stripping from the group members, which finally forms an intra-group light component (IGL). Therefore, the distribution of the IGL should be related to the distribution of the total mass in the compact group and its dynamical status. In this study we consider the distribution and fract…
We have explored the properties of a peculiar object detected in deep optical imaging and located at the tip of an HI tail emerging from Hickson Compact Group 16. Using multiband photometry from infrared to ultraviolet, we were able to constrain its stellar age to 58$^{+22}_{-9}$ Myr with a rather high metallicity of [Fe/H] = $-$0.16$^{+0.43}_{-0.41}$ for its stellar mass of M$_\star$ = 4.2$\times$10$^6$ M$_\odot$, a typical signature of tidal dwarf galaxies. The structural properties of this object are similar to those of diffuse galaxies, with a round and featureless morphology, a large effe…
We use the LOFAR Two-metre Sky Survey (LoTSS) Data Release I to identify the groups of galaxies (and individual galaxies) from the Hickson Compact Groups and Magnitude Limited Compact Groups samples that emit at the frequency of 150\,MHz, characterise their radio emission (extended or limited to the galaxies), and compare new results to earlier observations and theoretical predictions. The detection of 73 systems (and 7 more -- probably) out of 120, of which as many as 17 show the presence of extended radio structures, confirms the previous hypothesis of the common character of the magnetic fi…
In order to test a possible evolutionary scenario of high-$z$ compact quiescent galaxies (cQGs) that they can survive as local compact cores embedded in local massive galaxies with different morphology classes, we explore the star formation histories of local compact cores according to their spectral analysis. We build a sample of 182 massive galaxies with compact cores (${M}_{*,{\rm core}} > 10^{10.6} {\rm M}_\odot$) at $0.02 \leq z \leq 0.06$ from SDSS DR7 spectroscopic catalogue. STARLIGHT package is used to analyze the median stacked spectra and derive the stellar ages and metallicities. O…
Massive quiescent compact galaxies have been discovered at high redshifts, associated with rapid compaction and cessation of star formation (SF). In this work we set out to quantify the time-scales in which SF is quenched in compact galaxies at intermediate redshifts. For this, we select a sample of green valley galaxies within the COSMOS field in the midst of quenching their SF at $0.5<z<1.0$ that exhibit varying degrees of compactness. Based on the H$δ$ absorption line and the 4000 Å\ break of coadded zCOSMOS spectra for sub-samples of normal-sized and compact galaxies we determine quenching…
Optically-compact star-forming galaxies (SFGs) have been proposed as immediate progenitors of quiescent galaxies, although their origin and nature are debated. Were they formed in slow secular processes or in rapid merger-driven starbursts? Addressing this question would provide fundamental insight into how quenching occurs. We explore the location of the general population of galaxies with respect to fundamental star-forming and structural relations, identify compact SFGs based on their stellar core densities, and study three diagnostics of the burstiness of star formation: 1) Star formation …
We identify and characterize compact dwarf starburst (CDS) galaxies in the RESOLVE survey, a volume-limited census of galaxies in the local universe, to probe whether this population contains any residual ``blue nuggets,'' a class of intensely star-forming compact galaxies first identified at high redshift $z$. Our 50 low-$z$ CDS galaxies are defined by dwarf masses (stellar mass $M_* < 10^{9.5}$ M$_{\odot}$), compact bulged-disk or spheroid-dominated morphologies (using a quantitative criterion, $μ_Δ> 8.6$), and specific star formation rates above the defining threshold for high-$z$ blue nugg…
Keck-I MOSFIRE spectroscopy of compact star-forming galaxies at z$\gtrsim$2: High velocity dispersions in progenitors of compact quiescent galaxies
本文介绍了13个致密恒星形成星系（SFG）的近红外光谱，这些星系的恒星形成速率为SFR $\sim$ 100 M $_{\odot}$ y $^{-1}$，质量为log（M/M $_{\odot}$）$\sim10.8$，红移为$2\leq z \leq2.5$。它们的高积分气体速度色散$σ_{\rm{int}}$ =230 $^{+40}_{-30}$ km s $^{-1}$，从H $_α$和[OIII]的发射线测量，以及由此产生的M $_{\star}-σ_{\rm{int}}$关系和M $_{\star}$ $-$ M $_{\rm{dyn}}$都匹配得很好的致密静止星系在$z\sim2$，从恒星吸收线测量。由于log（M $_{\star}$ /M $_{\rm{dyn}}$）$=-0.06\pm0.2$ dex，这些紧凑的SFG看起来是动态松弛的和更进化的，即，在气体和暗物质（$<$ 13 $^{+17}_{-13}$ \%）比他们的非紧凑SFG同行在同一时期更贫化。在没有注入外部气体的情况下，耗尽的时间尺度很短，小于$\sim$ 3亿年。这一发现为我们新的动力学证据链增加了另一个环节，即$z\gtrsim2$的致密SFG已经失去了气体，成为$z\sim2$致密静止星系的直接祖先。
