scholarly journals Clues from deep HST images to galaxy formation and the role of mergers

1999 ◽  
Author(s):  
Rogier A. Windhorst ◽  
Seth H. Cohen ◽  
Ian Waddington
Keyword(s):  
Galaxy Formation

scholarly journals The Role of Radio Loud Phase of Nuclear Activity in Galaxy Formation and Evolution

2013 ◽  
Vol 9 (S304) ◽  
pp. 419-420
Author(s):  
Gabriel A. Ohanian
Keyword(s):  
Galaxy Formation ◽  
Subsequent Development ◽  
Nuclear Activity ◽  
Evolution Of Galaxies ◽  
Galaxy Formation And Evolution ◽  
Formation And Evolution ◽  
Key Questions

AbstractKey questions, which arise when one tries to clear up a problem of formation and evolution of galaxies, is the question of energy: what is the energetic budget of AGN owing to form galaxies and provide its subsequent development? Hence, for understanding the formation and evolution of galaxies, it is important to estimate the energetic budget of AGN which we try to do involving radio loud phase of nuclear activity.

The Role of Heating and Enrichment in Galaxy Formation

2001 ◽  
Vol 549 (1) ◽  
pp. 28-45 ◽  
Author(s):  
Evan Scannapieco ◽  
Tom Broadhurst
Keyword(s):  
Galaxy Formation

The role of AGB stars in Galactic and cosmic chemical enrichment

2018 ◽  
Vol 14 (S343) ◽  
pp. 247-257
Author(s):  
Chiaki Kobayashi ◽  
Christopher J. Haynes ◽  
Fiorenzo Vincenzo
Keyword(s):  
Electron Capture ◽  
Galaxy Formation ◽  
Neutron Capture ◽  
Slow Neutron ◽  
Asymptotic Giant Branch ◽  
Agb Stars ◽  
Capture Process ◽  
Chemical Enrichment ◽  
Cno Abundances

AbstractThe role of asymptotic giant branch (AGB) stars in chemical enrichment is significant for producing 12,13C, 14N, F, 25,26Mg, 17O and slow neutron-capture process (s-process) elements. The contribution from super-AGB stars is negligible in classical, one-zone chemical evolution models, but the mass ranges can be constrained through the contribution from electron-capture supernovae and possibly hybrid C+O+Ne white dwarfs, if they explode as Type Iax supernovae. In addition to the recent s-process yields of AGB stars, we include various sites for rapid neutron-capture processes (r-processes) in our chemodynamical simulations of a Milky Way type galaxy. We find that neither electron-capture supernovae or neutrino-driven winds are able to adequately produce heavy neutron-capture elements such as Eu in quantities to match observations. Both neutron-star mergers (NSMs) and magneto-rotational supernovae (MRSNe) are able to produce these elements in sufficient quantities. Using the distribution in [Eu/(Fe, α)] – [Fe/H], we predict that NSMs alone are unable to explain the observed Eu abundances, but may be able to together with MRSNe. In order to discuss the role of long-lifetime sources such as NSMs and AGB stars at the early stages of galaxy formation, it is necessary to use a model that can treat inhomogeneous chemical enrichment, such as in our chemodynamical simulations. In our cosmological, chemodynamical simulations, we succeed in reproducing the observed N/O-O/H relations both for global properties of galaxies and for local inter-stellar medium within galaxies, without rotation of stars. We also predict the evolution of CNO abundances of disk galaxies, from which it will be possible to constrain the star formation histories.

Constraints on Elliptical Galaxy Formation from Dry Mergers

2006 ◽  
Vol 2 (S235) ◽  
pp. 195-195
Author(s):  
Julia M. Comerford ◽  
Eliot Quataert ◽  
Chung-Pei Ma
Keyword(s):  
Galaxy Formation ◽  
Elliptical Galaxy ◽  
Elliptical Galaxies ◽  
Analytic Model ◽  
Dark Matter Halos ◽  
Early Type ◽  
Mass Assembly ◽  
Minor Mergers ◽  
Analytic Models

Recent observations suggest that dissipationless mergers of elliptical galaxies build up the population of massive early-type galaxies (Bell et al. 2004; Faber et al. 2006). This type of merger is observed in galaxy clusters (Tran et al. 2005) and predicted by semi-analytic models which find mass assembly times significantly later than star-formation times for the most massive elliptical galaxies (de Lucia & Blaizot 2006). Here, we use a semi-analytic model of minor mergers of dark matter halos to examine the role of dry minor mergers in elliptical galaxy formation.

scholarly journals Early-type galaxy formation: understanding the role of the environment

2014 ◽  
Vol 10 (S309) ◽  
pp. 291-292
Author(s):  
Ricardo Demarco ◽  
Alessandro Rettura ◽  
Chris Lidman ◽  
Julie Nantais ◽  
Yara Jaffe ◽  
...  
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Galaxy Formation ◽  
Early Type ◽  
Cluster Galaxy ◽  
Cluster Galaxies ◽  
Physical Mechanisms ◽  
Characteristic Features ◽  
Early Type Galaxy

AbstractOne of the most characteristic features of galaxy clusters is the so-called “red sequence” (RS) of early-type galaxies. Since these galaxies are, in general, devoid of gas and dust, their red colors are mainly a consequence of their passive nature. However, the physical mechanisms responsible for quenching their star formation, thus originating the RS, are poorly understood. Environmental effects should play a significant role in the formation of the RS by transforming the observed galaxy properties from late to early-type ones. In this respect, we have initiated a KMOS program aimed at studying the kinematical structure of cluster galaxies at 0.8 < z < 1.7 in an effort to disentangle the physical mechanisms responsible for cluster galaxy evolution and the formation of the RS.

scholarly journals Evolutionary paths among different red galaxy types at 0.3 < z < 1.5 and the build-up of massive E-S0's

2012 ◽  
Vol 8 (S295) ◽  
pp. 176-176
Author(s):  
Jesús Gallego ◽  
Mercedes Prieto ◽  
M. Carmen Eliche-Moral ◽  
Marc Balcells ◽  
David Cristóbal-Hornillos ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Dominant Role ◽  
Regional Government ◽  
Massive Galaxies ◽  
Combining Data ◽  
Red Galaxies ◽  
Evolutionary Paths ◽  
First Time ◽  
Red Sequence

AbstractSome recent observations seem to disagree with hierarchical theories of galaxy formation on the role of major mergers in a late build-up of massive early-type galaxies. We re-address this question by analysing the morphology, structural distortion level, and star formation enhancement of a sample of massive galaxies (M* > 5 × 1010M⊙) lying on the Red Sequence and its surroundings at 0.3 < z < 1.5. We have used an initial sample of ~1800 sources with Ks < 20.5 mag over an area ~155 arcmin2 on the Groth Strip, combining data from the Rainbow Extragalactic Database and the GOYA Survey. Red galaxy classes that can be directly associated to intermediate stages of major mergers and to their final products have been defined. For the first time we report observationally the existence of a dominant evolutionary path among massive red galaxies at 0.6 < z < 1.5, consisting in the conversion of irregular disks into irregular spheroids, and of these ones into regular spheroids. This result points to: 1) the massive red regular galaxies at low redshifts derive from the irregular ones populating the Red Sequence and its neighbourhood at earlier epochs up to z ~ 1.5; 2) the progenitors of the bulk of present-day massive red regular galaxies have been blue disks that have migrated to the Red Sequence majoritarily through major mergers at 0.6 < z < 1.2 (these mergers thus starting at z ~ 1.5); 3) the formation of E-S0's that end up with M* > 1011M⊙ at z = 0 through gas-rich major mergers has frozen since z ~ 0.6. Our results support that major mergers have played the dominant role in the definitive build-up of present-day E-S0's with M* > 1011M⊙ at 0.6 < z < 1.2, in good agreement with the hierarchical scenario proposed in the Eliche-Moral et al. (2010a) model (see also Eliche-Moral et al. 2010b). This study is published in Prieto et al. (2012).Supported by the Spanish Ministry of Science and Innovation (MICINN) under projects AYA2009-10368, AYA2006-12955, AYA2010-21887-C04-04, and AYA2009-11137, by the Madrid Regional Government through the AstroMadrid Project (CAM S2009/ESP-1496), and by the Spanish MICINN under the Consolider-Ingenio 2010 Program grant CSD2006-00070: “First Science with the GTC” (http://www.iac.es/consolider-ingenio-gtc/). S. D. H. & G.

scholarly journals JETS AND OUTFLOWS IN RADIO GALAXIES: IMPLICATIONS FOR AGN FEEDBACK

2012 ◽  
Vol 08 ◽  
pp. 396-399 ◽  
Author(s):  
ELEONORA TORRESI ◽  
PAOLA GRANDI ◽  
ELISA COSTANTINI ◽  
GIORGIO G. C. PALUMBO
Keyword(s):  
Black Holes ◽  
Galaxy Formation ◽  
Surrounding Medium ◽  
Radio Galaxies ◽  
Broad Line ◽  
Jets And Outflows ◽  
Massive Black Holes ◽  
X Ray ◽  
Formation And Evolution

One of the main debated astrophysical problems is the role of the AGN feedback in galaxy formation. It is known that massive black holes have a profound effect on the formation and evolution of galaxies, but how black holes and galaxies communicate is still an unsolved problem. For Radio Galaxies, feedback studies have mainly focused on jet/cavity systems in the most massive and X–ray luminous galaxy clusters. The recent high–resolution detection of warm absorbers in some Broad Line Radio Galaxies allow us to investigate the interplay between the nuclear engine and the surrounding medium from a different perspective. We report on the detection of warm absorbers in two Broad Line Radio Galaxies, 3C 382 and 3C 390.3, and discuss the physical and energetic properties of the absorbing gas. Finally, we attempt a comparison between radio–loud and radio–quiet outflows.

scholarly journals Implications of Early Cooling Flows and Galactic Winds for the Evolution of Deuterium

2000 ◽  
Vol 198 ◽  
pp. 535-539
Author(s):  
Amancio C. S. Friaça
Keyword(s):  
Absorption Line ◽  
Galaxy Formation ◽  
Spatial Scales ◽  
High Redshift ◽  
Cooling Flows ◽  
Galactic Winds ◽  
Important Constraint

The deuterium abundances in high-redshift QSO absorption-line systems could be an important constraint in models of galaxy formation. Here we investigate the role of galactic winds and massive cooling flows present during the formation of galaxies on the evolution of deuterium abundance. Destruction factors are calculated and the time and spatial scales for the dispersal through galactic winds of the processed deuterium-depleted gas are presented and related to the D/H determinations for QSO absorption-line systems. The calculations are derived from a chemodynamical model within a scenario in which the absorbers are located inside the hot halo of a young galaxy.

scholarly journals Gas Accretion and Mergers in Massive Galaxies at z ~ 2

2012 ◽  
Vol 8 (S295) ◽  
pp. 45-48
Author(s):  
C. J. Conselice ◽  
Jamie Ownsworth ◽  
Alice Mortlock ◽  
Asa F. L. Bluck ◽  
Keyword(s):  
Galaxy Formation ◽  
Theoretical Models ◽  
Massive Galaxies ◽  
A Value ◽  
The Galaxy ◽  
Hydrodynamical Simulations ◽  
Minor Mergers ◽  
Galaxy Assembly ◽  
Gas Accretion

AbstractGalaxy assembly is an unsolved problem, with ΛCDM theoretical models unable to easily account for among other things, the abundances of massive galaxies, and the observed merger history. We show here how the problem of galaxy formation can be addressed in an empirical way without recourse to models. We discuss how galaxy assembly occurs at 1.5 < z < 3 examining the role of major and minor mergers, and gas accretion from the intergalactic medium in forming massive galaxies with log M* > 11 found within the GOODS NICMOS Survey (GNS). We find that major mergers, minor mergers and gas accretion are roughly equally important in the galaxy formation process during this epoch, with 64% of the mass assembled through merging and 36% through accreted gas which is later converted to stars, while 58% of all new star formation during this epoch arises from gas accretion. We also discuss how the total gas accretion rate is measured as Ṁ = 90±40 M⊙ yr−1 at this epoch, a value close to those found in some hydrodynamical simulations.

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