scholarly journals Truncated Star Formation in Compact Groups of Galaxies: A Stellar Population Study

2006 ◽  
Vol 133 (1) ◽  
pp. 330-346 ◽  
Author(s):  
Ignacio G. de la Rosa ◽  
Reinaldo R. de Carvalho ◽  
Alexandre Vazdekis ◽  
Beatriz Barbuy
Keyword(s):  
Star Formation ◽  
Population Study ◽  
Stellar Population ◽  
Compact Groups ◽  
Groups Of Galaxies

scholarly journals Star-forming regions in the intragroup medium of compact groups of galaxies

2009 ◽  
Vol 5 (S262) ◽  
pp. 440-441
Author(s):  
S. Torres-Flores ◽  
C. Mendes de Oliveira ◽  
D. F. de Mello ◽  
P. Amram ◽  
H. Plana ◽  
...  
Keyword(s):  
Star Formation ◽  
Dwarf Galaxy ◽  
Early Stage ◽  
Velocity Fields ◽  
Compact Groups ◽  
Advanced Stage ◽  
Groups Of Galaxies ◽  
Star Forming ◽  
Star Forming Regions ◽  
Fabry Perot

AbstractWe present the results of a multiwavelength campaign searching for young objects in the intragroup medium of seven compact groups of galaxies: HCG 2, 7, 22, 23, 92, 100 and NGC 92. We used Fabry-Perot velocity fields and rotation curves together with GALEX NUV and FUV images, optical R-band and HI maps to evaluate the stage of interaction of each group. We conclude that groups (i) HCG 7 and HCG 23 are in an early stage of interaction, (ii) HCG 2 and HCG 22 are mildly interacting, and (iii) HCG 92, HCG 100 and NGC 92 are in a late stage of evolution. Evolved groups have a population of young objects in their intragroup medium while no such population is found within the less evolved groups. We also report the discovery of a tidal dwarf galaxy candidate in the tail of NGC 92. These three groups, besides containing galaxies which have peculiar velocity fields, also show extended HI tails. Our results indicate that the advanced stage of evolution of a group together with the presence of intragroup HI clouds may lead to star formation in the intragroup medium.

scholarly journals Star formation in the intragroup medium and other diagnostics of the evolutionary stages of compact groups of galaxies

2009 ◽  
Vol 507 (2) ◽  
pp. 723-746 ◽  
Author(s):  
S. Torres-Flores ◽  
C. Mendes de Oliveira ◽  
D. F. de Mello ◽  
P. Amram ◽  
H. Plana ◽  
...  
Keyword(s):  
Star Formation ◽  
Compact Groups ◽  
Groups Of Galaxies

scholarly journals Intragroup Gas in Differently Evolved Compact Groups of Galaxies

2006 ◽  
Vol 2 (S235) ◽  
pp. 221-221
Author(s):  
L. Verdes-Montenegro ◽  
J. Rasmussen ◽  
T. Ponman ◽  
M. S. Yun ◽  
S. Borthakur
Keyword(s):  
Star Formation ◽  
Detection Rate ◽  
Virgo Cluster ◽  
Radio Continuum ◽  
Continuum Emission ◽  
Compact Groups ◽  
Evolutionary Status ◽  
X Ray ◽  
Groups Of Galaxies ◽  
Star Formation Activity

AbstractCompact groups are highly isolated, dense galaxy systems, and therefore tidal interactions are expected to be continuous and dynamically important. For this reason they represent unique laboratories for studying interactions in extreme environments and tidally induced star formation as well as morphological and dynamical evolution of galaxies in general. This study is part of a broader investigation of the evolutionary status of HCGs. In order to explain the HI deficiency found in compact groups of galaxies we have proposed a broad evolutionary scenario in which the amount of HI decreases with the secular evolutionary state of a group. The fate of this gas is however not clear. In order to investigate the physical mechanisms responsible for these changes in the gas content of galaxies we have started a study to look for an intragroup medium (IGM). We have considered this IGM to be neutral (see e.g. reports of HI clouds within Virgo cluster (Oosterloo & Van Gorkom 2005), or hot gas (a higher X-ray detection rate of HI deficient groups is found relative to groups with a normal HI content, Verdes-Montenegro et al. 2001). Enhanced star formation activity might also be contributing to exhausting the gas supply. We have observed 25 HCGs with diverse HI content and distribution with the Green Bank radiotelescope, and performed VLA-HI as well as X-ray (XMM or Chandra) observations of the most HI deficient groups HCG 7, 15, 30, 37, 40, 44 and 97. We have also analysed FIR data from Verdes-Montenegro et al. (1998).Our results are: (a) HI deficient groups show a larger amount of diffuse neutral and X-ray gas when compared to non-deficient ones, consistent with our evolutionary picture; (b) Most groups are still deficient after including diffuse gas. (c) A hot IGM is not detected in most of these systems, but the detection rate is higher for the high velocity dispersion groups, and in these cases ram pressure stripping could potentially cause the observed HI-deficiency. (d) In several of these groups we detect intragroup radio continuum emission, which is surprising since similar features were seen previously only in massive clusters (known as “relic” sources). (e) Star formation activity traced by FIR luminosity is not enhanced, contrary to the general expectation of tidally interacting systems.Hence neither the presence of a hot or cold IGM nor star formation activity seem to be able to uniquely explain the HI deficiency found in compact groups of galaxies. We plan to explore the possibility that earlier starbursts could have contributed to the present HI deficiency.

scholarly journals Stellar population properties of ETGs in compact groups of galaxies

2020 ◽  
Vol 493 (3) ◽  
pp. 3238-3254
Author(s):  
Tatiana C Moura ◽  
Reinaldo R de Carvalho ◽  
Sandro B Rembold ◽  
Marina Trevisan ◽  
Andre L B Ribeiro ◽  
...  
Keyword(s):  
Galaxy Evolution ◽  
Stellar Population ◽  
Velocity Dispersion ◽  
Group Velocity Dispersion ◽  
Gas Content ◽  
Dynamical Analysis ◽  
Compact Groups ◽  
Low Mass Stars ◽  
Groups Of Galaxies ◽  
Low Mass

ABSTRACT We present results on the study of the stellar population in early-type galaxies (ETGs) belonging to 151 compact groups (CGs). We also selected a field sample composed of 846 ETGs to investigate environmental effects on galaxy evolution. We find that the dependences of mean stellar ages, [Z/H] and [α/Fe] on central stellar velocity dispersion are similar, regardless where the ETG resides, CGs or field. When compared to the sample of centrals and satellites from the literature, we find that ETGs in CGs behave similarly to centrals, especially those embedded in low-mass haloes ($M_{\mathrm{ h}} \lt 10^ {12.5}\, \mathrm{M}_{\odot }$). Except for the low-mass limit, where field galaxies present a star-forming signature, not seen in CGs, the ionization agent of the gas in CG and field galaxies seem to be similar due to hot, evolved low-mass stars. However, field ETGs present an excess of H α emission relative to ETGs in CGs. Additionally, we performed a dynamical analysis, which shows that CGs present a bimodality in the group velocity dispersion distribution – a high- and low-σ mode. Our results indicate that high-σ groups have a smaller fraction of spirals, shorter crossing times, and a more luminous population of galaxies than the low-σ groups. It is important to emphasize that our findings point to a small environmental impact on galaxies located in CGs. The only evidence we find is the change in gas content, suggesting environmentally driven gas loss.

scholarly journals A Herschel and CARMA view of CO and [C ii] in Hickson Compact groups

2014 ◽  
Vol 10 (S309) ◽  
pp. 178-181
Author(s):  
Katherine Alatalo ◽  
Philip N. Appleton ◽  
Ute Lisenfeld
Keyword(s):  
Star Formation ◽  
Interstellar Medium ◽  
Compact Groups ◽  
Large Set ◽  
Space Observatory ◽  
Groups Of Galaxies ◽  
Preliminary Results ◽  
Evolution Of Galaxies ◽  
Hickson Compact Groups ◽  
Cold Dust

AbstractUnderstanding the evolution of galaxies from the starforming blue cloud to the quiescent red sequence has been revolutionized by observations taken with Herschel Space Observatory, and the onset of the era of sensitive millimeter interferometers, allowing astronomers to probe both cold dust as well as the cool interstellar medium in a large set of galaxies with unprecedented sensitivity. Recent Herschel observations of of H2-bright Hickson Compact Groups of galaxies (HCGs) has shown that [C ii] may be boosted in diffuse shocked gas. CARMA CO(1–0) observations of these [C ii]-bright HCGs has shown that these turbulent systems also can show suppression of SF. Here we present preliminary results from observations of HCGs with Herschel and CARMA, and their [C ii] and CO(1–0) properties to discuss how shocks influence galaxy transitions and star formation.

scholarly journals SOME LIKE IT HOT: LINKING DIFFUSE X-RAY LUMINOSITY, BARYONIC MASS, AND STAR FORMATION RATE IN COMPACT GROUPS OF GALAXIES

2014 ◽  
Vol 790 (2) ◽  
pp. 132 ◽  
Author(s):  
Tyler D. Desjardins ◽  
Sarah C. Gallagher ◽  
Ann E. Hornschemeier ◽  
John S. Mulchaey ◽  
Lisa May Walker ◽  
...  
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Compact Groups ◽  
X Ray ◽  
Groups Of Galaxies ◽  
Baryonic Mass

scholarly journals The Origin of Intergalactic Light in Compact Groups of Galaxies

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 303
Author(s):  
Mark J. Henriksen
Keyword(s):  
Star Formation ◽  
Formation Rate ◽  
High Mass ◽  
Compact Groups ◽  
Source Population ◽  
X Ray ◽  
Groups Of Galaxies ◽  
Evolutionary Phase ◽  
X Ray Binaries ◽  
Lower Luminosity

We investigate the origin of intergalactic light (IGL) in close groups of galaxies. IGL is hypothesized to be the byproduct of interaction and merger within compact groups. Comparing the X-ray point source population in our sample of compact groups that have intergalactic light with compact groups without IGL, we find marginal evidence for a small increase in ultra-luminous X-ray sources (ULXs). There is also a significant bias towards lower luminosity high mass X-ray binaries (HMXRBs). We interpret this as an indication that groups with visible IGL represent a later evolutionary phase than other compact groups. They have galaxies characterized by quenching of star formation (lower star formation rate (SFR) inferred from lower HMXRB luminosity) after stellar material has been removed from the galaxies into the intergalactic medium, which is the source of the IGL. We conclude that the presence of an increased fraction of ULXs is due to past interaction and mergers within groups that have IGL.

scholarly journals Star Formation and Environment in Compact Groups of Galaxies

2000 ◽  
Vol 174 ◽  
pp. 349-354
Author(s):  
J. Iglesiás-Paramo ◽  
J. M. Vílchez
Keyword(s):  
Dark Matter ◽  
Star Formation ◽  
Environmental Effects ◽  
Compact Groups ◽  
Disk Galaxies ◽  
Early Type ◽  
Groups Of Galaxies ◽  
Dynamical State ◽  
Dynamical Parameters

AbstractHα luminosities are presented in order to study the Star Formation Rates (SFRs) of a sample of galaxies in compact groups from Hickson's (1982) catalogue. Although the comparison of the SFRs of the disk galaxies in our sample with those of a sample of field galaxies yielded no difference between the average SFRs for disk galaxies in compact groups and in the field, environmental effects seem to influence the Hα luminosities of late and early-type galaxies in compact groups. No relationship was found between the total normalized Hα luminosities of the groups and some dynamical parameters, indicating that the dynamical state of the group does not influence the SFR of the group. The lack of dominant interaction induced starbursts in our sample is compatible with a scenario for compact groups of galaxies in which the dark matter of the group is arranged in a common halo, thereby preventing a fast collapse of the galaxies.

Infrared Studies of the Young Stellar Population of 30 Doradus

1980 ◽  
Vol 4 (1) ◽  
pp. 90-92
Author(s):  
P. J. McGregor ◽  
A. R. Hyland
Keyword(s):  
Star Formation ◽  
Stellar Population ◽  
Cluster Formation ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Formation Processes ◽  
Excellent Opportunity ◽  
Infrared Studies ◽  
30 Doradus

The 30 Doradus region offers an excellent opportunity to study cluster formation processes and recent star formation in the Large Magellanic Cloud.

scholarly journals HI Distribution in Extreme Dwarf Irregulars and Dwarf Spheroidals

1998 ◽  
Vol 11 (1) ◽  
pp. 121-122
Author(s):  
Claude Carignan
Keyword(s):  
Star Formation ◽  
Stellar Population ◽  
Large Fraction ◽  
Dwarf Spheroidal Galaxies ◽  
Irregular Galaxies ◽  
Single Burst ◽  
Dwarf Spheroidals ◽  
Dwarf Irregular Galaxies ◽  
Spheroidal Galaxies

Recent studies (Puche & Westpfahl 1994, Young & Lo 1996) have shown that the distribution of HI in some extreme low luminosity dwarf irregular galaxies (e.g. M81dwA, Holmberg I, Leo A) tends to have a ring-like (or shell-like) distribution which suggests that a single burst of star formation could expell most of the remaining ISM (or at least a large fraction of it) from the system. In view of this, Puche & Westpfahl (1994) suggested that in dwarf spheroidal galaxies, the HI should be found at large radii since no young stellar population is observed in most of them.

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