Stellar Populations in the Host Galaxies of Markarian 1014, IRAS 07598+6508, and Markarian 231

2000 ◽  
Vol 120 (4) ◽  
pp. 1750-1763 ◽  
Author(s):  
Gabriela Canalizo ◽  
Alan Stockton
Keyword(s):  
Stellar Populations ◽  
Host Galaxies

scholarly journals Supercluster A2142 and collapse in action: infalling and merging groups and galaxy transformations

2018 ◽  
Vol 620 ◽  
pp. A149 ◽  
Author(s):  
Maret Einasto ◽  
Mirt Gramann ◽  
Changbom Park ◽  
Juhan Kim ◽  
Boris Deshev ◽  
...  
Keyword(s):  
Galactic Nuclei ◽  
Stellar Populations ◽  
Normal Mixture ◽  
Host Galaxies ◽  
Galaxy Groups ◽  
Dynamical State ◽  
Spherical Collapse ◽  
Stellar Ages ◽  
Collapse Model ◽  
Formation And Evolution

Context. Superclusters with collapsing cores represent dynamically evolving environments for galaxies, galaxy groups, and clusters.Aims. We study the dynamical state and properties of galaxies and groups in the supercluster SCl A2142 that has a collapsing core, to understand its possible formation and evolution.Methods. We find the substructure of galaxy groups using normal mixture modelling. We have used the projected phase space (PPS) diagram, spherical collapse model, clustercentric distances, and magnitude gap between the brightest galaxies in groups to study the dynamical state of groups and to analyse group and galaxy properties. We compared the alignments of groups and their brightest galaxies with the supercluster axis.Results. The supercluster core has a radius of about 8h−1Mpc and total massMtot≈ 2.3 × 1015h−1M⊙and is collapsing. Galaxies in groups on the supercluster axis have older stellar populations than off-axis groups, with median stellar ages 4 − 6 and < 4 Gyr, correspondingly. The cluster A2142 and the group Gr8 both host galaxies with the oldest stellar populations among groups in SCl A2142 having the median stellar aget> 8 Gyr. Recently quenched galaxies and active galactic nuclei (AGNs) are mostly located at virial radii or in merging regions of groups, and at clustercentric distancesDc≈ 6h−1Mpc. The most elongated groups lie along the supercluster axis and are aligned with it. Magnitude gaps between the brightest galaxies of groups are less than one magnitude, suggesting that groups in SCl A2142 are dynamically young.Conclusions. The collapsing core of the supercluster, infall of galaxies and groups, and possible merging groups, which affect galaxy properties and may trigger the activity of AGNs, show how the whole supercluster is evolving.

scholarly journals Stellar Populations in the Most Luminous Obscured Quasars at z > 0.5

2012 ◽  
Vol 8 (S295) ◽  
pp. 178-178
Author(s):  
Xin Liu
Keyword(s):  
Black Holes ◽  
Velocity Dispersion ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Cosmic Time ◽  
Stellar Populations ◽  
Spectroscopic Studies ◽  
Number Density ◽  
Host Galaxies ◽  
Crucial Information

There is evidence that the growth of stellar populations and supermassive black holes (SMBHs) are coupled across cosmic time: the redshift evolution of star formation rate and quasar number density are similar; SMBH masses in local inactive galaxies are correlated with the velocity dispersion of their stellar bulges. Models predict that SMBHs predominantly grow in brief quasar phases accompanied by starbursts, but on-going starbursts in luminous quasars have been difficult to quantify. There have been extensive photometric studies of quasar host galaxies. However, spectroscopic studies that provide crucial information on stellar populations such as age and velocity dispersion are scarce, especially at the highest luminosities, where the stars are vastly outshone by the quasar.

scholarly journals Understanding mechanical feedback from HERGs and LERGs

2018 ◽  
Vol 14 (A30) ◽  
pp. 86-89
Author(s):  
Imogen H. Whittam
Keyword(s):  
Galaxy Evolution ◽  
Stellar Populations ◽  
Radio Galaxies ◽  
High Excitation ◽  
Host Galaxies ◽  
Radio Jets ◽  
Accretion Rates ◽  
Hydrodynamical Simulations ◽  
Mechanical Feedback

AbstractThe properties of ∼ 1000 high-excitation and low-excitation radio galaxies (HERGs and LERGs) selected from the Heywood et al. (2016) 1 – 2 GHz VLA survey of Stripe 82 are investigated. The HERGs in this sample are generally found in host galaxies with younger stellar populations than LERGs, consistent with other work. The HERGs tend to accrete at a faster rate than the LERGs, but there is more overlap in the accretion rates of the two classes than has been found previously. We find evidence that mechanical feedback may be significantly underestimated in hydrodynamical simulations of galaxy evolution; 84 % of this sample release more than 10 % of their energy in mechanical form. Mechanical feedback is significant for many of the HERGs in this sample as well as the LERGs; nearly 50 % of the HERGs release more than 10 % of their energy in their radio jets.

scholarly journals A Systematic Analysis of Stellar Populations in the Host Galaxies of SDSS Type I QSOs

2018 ◽  
Vol 864 (1) ◽  
pp. 32 ◽  
Author(s):  
Jun-Jie Jin ◽  
Yi-Nan Zhu ◽  
Xian-Min Meng ◽  
Feng-Jie Lei ◽  
Hong Wu
Keyword(s):  
Stellar Populations ◽  
Type I ◽  
Host Galaxies ◽  
Systematic Analysis

scholarly journals STELLAR POPULATIONS OF ULTRAVIOLET-SELECTED ACTIVE GALACTIC NUCLEI HOST GALAXIES ATz∼ 2–3

2012 ◽  
Vol 760 (1) ◽  
pp. 74 ◽  
Author(s):  
Kevin N. Hainline ◽  
Alice E. Shapley ◽  
Jenny E. Greene ◽  
Charles C. Steidel ◽  
Naveen A. Reddy ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Stellar Populations ◽  
Host Galaxies

Stellar populations and ages of ultra-hard X-ray AGN in the BASS survey

2019 ◽  
Vol 15 (S356) ◽  
pp. 370-370
Author(s):  
Mirjana Pović
Keyword(s):  
Galaxy Evolution ◽  
Selection Criteria ◽  
Stellar Populations ◽  
X Rays ◽  
Host Galaxies ◽  
X Ray ◽  
The Past ◽  
Open Questions ◽  
Stellar Ages

AbstractConnection between star formation and AGN activity has been studied widely over the past years, which shown to be very important for understanding better the role of AGN in galaxy evolution. In this context, what are the stellar ages and average stellar populations of AGN host galaxies, and if there are any differences depending on AGN type, are still open questions that brought many inconsistencies, very often due to different selection criteria used. The AGN sample detected in the ultra-hard X-rays (14–195 keV) by the Swift BAT telescope is not affected by obscuration nor is it contaminated by stellar emission, and presents some of the most unbiased samples. In this talk we will present the results obtained on AGN stellar populations and ages through spectral fittings by using the Swift-BAT AGN Spectroscopic Survey (BASS) which gives us an unique opportunity to understand better the connection between AGN and their host galaxies.

scholarly journals Stellar populations in hosts of giant radio galaxies and their neighbouring galaxies

2019 ◽  
Vol 624 ◽  
pp. A91 ◽  
Author(s):  
A. Kuźmicz ◽  
B. Czerny ◽  
C. Wildy
Keyword(s):  
Star Formation ◽  
Galaxy Formation ◽  
Intergalactic Medium ◽  
Spectral Synthesis ◽  
Control Sample ◽  
Stellar Populations ◽  
Radio Galaxies ◽  
Host Galaxy ◽  
Radio Sources ◽  
Host Galaxies

Context. Giant radio galaxies (with projected linear size of radio structure larger than 0.7 Mpc) are very rare and unusual objects. Only ∼5% of extended radio sources reach such sizes. Understanding of the processes responsible for their large sizes is crucial to further our knowledge about the radio source’s evolution. Aims. We check the hypothesis that giants become extremely large due to the specific history of their host galaxy formation, as well as in the context of the cluster or group of galaxies where they evolve. Therefore we study the star formation histories in their host galaxies and in galaxies located in their neighbourhood. Methods. We studied 41 giant-size radio galaxies as well as galaxies located within a radius of 5 Mpc around giants to verify whether the external conditions of the intergalactic medium somehow influence the internal evolution of galaxies in the group/cluster. We compared the results with a control sample of smaller-sized Fanaroff–Riley type II radio galaxies and their neighbouring galaxies. We fit stellar continua in all galaxy spectra using the spectral synthesis code STARLIGHT and provide statistical analysis of the results. Results. We find that hosts of giant radio galaxies have a larger amount of intermediate age stellar populations compared with smaller-sized FRII radio sources. The same result is also visible when we compare neighbouring galaxies located up to 1.5 Mpc around giants and FRIIs. This may be evidence that star formation in groups with giants was triggered due to global processes occurring in the ambient intergalactic medium. These processes may also contribute to mechanisms responsible for the extremely large sizes of giants.

scholarly journals The stellar populations of host galaxies of supernovae

2012 ◽  
Vol 8 (S295) ◽  
pp. 321-321
Author(s):  
X. Shao ◽  
Y. C. Liang ◽  
M. Dennefeld ◽  
X. Y. Chen ◽  
G. H. Zhong ◽  
...  
Keyword(s):  
Stellar Populations ◽  
Absorption Lines ◽  
Core Collapse ◽  
Host Galaxies ◽  
Main Galaxy ◽  
Different Types ◽  
Galaxy Sample ◽  
Cross Matching

AbstractWe study and compare the stellar populations of host galaxies of different types of supernovae (SNe): SN Ia and core collapse SN (SN II and SN Ibc) at the same time. The 234 sample galaxies are selected by cross-matching the Asiago Supernova Catalogue (ASC) and the SDSS-DR7 main galaxy sample (MGS). The STARLIGHT software is used to analyze their stellar populations by fitting the continua and absorption lines of the hosts.

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