scholarly journals The influence of massive stars on the interstellar medium

1999 ◽  
Vol 193 ◽  
pp. 627-635
Author(s):  
M. Sally Oey
Keyword(s):  
Galaxy Formation ◽  
Massive Stars ◽  
Stellar Winds ◽  
H Ii Regions ◽  
Feedback Effects ◽  
Star Forming ◽  
Galaxy Formation And Evolution ◽  
Formation And Evolution ◽  
The Relationship ◽  
Warm Ionized Medium

On scales ranging from pcs to kpcs, the relationship between stellar and gaseous galactic components forms the basis for interpreting observations of galaxies and understanding galaxy formation and evolution. Feedback effects from massive stars dominate the structure, ionization, kinematics, and enrichment of the gaseous ISM in star-forming galaxies. On galactic scales, the ionizing radiation from these stars creates populations of H II regions and the diffuse, warm ionized medium. Likewise, superbubbles created by stellar winds and supernovae strongly influence the structure, kinematics, and balance of the multiphase ISM. This contribution reviews these feedback effects of massive stars on the global ISM.

scholarly journals Ultraviolet Population Synthesis of Starburst Galaxies Observed with HST

1995 ◽  
Vol 164 ◽  
pp. 461-461
Author(s):  
C. Robert ◽  
C. Leitherer ◽  
T.M. Heckman
Keyword(s):  
Galaxy Formation ◽  
Massive Stars ◽  
Starburst Galaxies ◽  
Stellar Winds ◽  
Spectral Features ◽  
Population Synthesis ◽  
Galaxy Formation And Evolution ◽  
Formation And Evolution ◽  
Spectroscopic Signatures

Starburst galaxies are ideal laboratories to study both the physics of massive stars and processes important in galaxy formation and evolution. Observations of starburst galaxies at UV wavelengths are crucial because only in this spectral regime can we directly observe the spectroscopic signatures of the hot, massive stars that power the emission at other wavebands. UV signatures from massive stars are mainly broad spectral features (e.g. P Cygni profiles of SiIVλ1400, and CIVλ1550) formed in the stellar winds.

Planetary nebulae in the (extra)-galactic context: Probing chemical evolution in star-forming galaxies

2018 ◽  
Vol 14 (S343) ◽  
pp. 174-180
Author(s):  
Letizia Stanghellini
Keyword(s):  
Galaxy Formation ◽  
Planetary Nebulae ◽  
H Ii Regions ◽  
Chemical Abundances ◽  
Star Forming ◽  
Galaxy Formation And Evolution ◽  
Formation History ◽  
Chemical Content ◽  
Formation And Evolution ◽  
Powerful Constraint

AbstractThe populations of planetary nebulae (PNe) probe metallicity and chemical content (and its evolution) of the parent galaxy, giving clues to galaxy formation and evolution. This sub-field of extra-galactic PN research has been particularly active in the recent years. Comparison of data and models yielded estimates of global cosmic enrichment and provided constraints to galaxy formation history. In external spiral galaxies, the chemical contents of PNe and H II regions can be compared to disclose possible evolution of the radial metallicity gradient, which is, in turn, a powerful constraint to galactic chemical evolutionary models. In the Milky Way, recent PN progenitor dating and new chemical abundances offer an updated look into our own Galaxy. Collectively, Galactic and extra-galactic radial metallicity gradients from emission-line probes (PNe and H II regions) can be compared to have a cosmological outlook on galactic evolution.

scholarly journals A Review of the Theory of Galactic Winds Driven by Stellar Feedback

Galaxies ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 114 ◽  
Author(s):  
Dong Zhang
Keyword(s):  
Galaxy Formation ◽  
Mass Function ◽  
Future Research ◽  
Star Forming ◽  
Stellar Feedback ◽  
Galactic Winds ◽  
Galaxy Formation And Evolution ◽  
Supernova Explosions ◽  
Formation And Evolution ◽  
Magnetohydrodynamic Simulations

Galactic winds from star-forming galaxies are crucial to the process of galaxy formation and evolution, regulating star formation, shaping the stellar mass function and the mass-metallicity relation, and enriching the intergalactic medium with metals. Galactic winds associated with stellar feedback may be driven by overlapping supernova explosions, radiation pressure of starlight on dust grains, and cosmic rays. Galactic winds are multiphase, the growing observations of emission and absorption of cold molecular, cool atomic, ionized warm and hot outflowing gas in a large number of galaxies have not been completely understood. In this review article, I summarize the possible mechanisms associated with stars to launch galactic winds, and review the multidimensional hydrodynamic, radiation hydrodynamic and magnetohydrodynamic simulations of winds based on various algorithms. I also briefly discuss the theoretical challenges and possible future research directions.

scholarly journals Dust reddening in star-forming galaxies

2012 ◽  
Vol 8 (S292) ◽  
pp. 291-291
Author(s):  
Ting Xiao ◽  
Tinggui Wang ◽  
Huiyuan Wang ◽  
Hongyan Zhou ◽  
Honglin Lu ◽  
...  
Keyword(s):  
Star Formation ◽  
Gas Phase ◽  
Galaxy Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Analytical Models ◽  
Star Forming ◽  
Crucial Component ◽  
Galaxy Formation And Evolution ◽  
Formation And Evolution

AbstractDust is a crucial component of galaxies in modifying the observed properties of galaxies. Previous studies have suggested that dust reddening in star-forming galaxies is correlated with star formation rate (SFR), luminosity, gas-phase metallicity (Z), stellar mass (M*) and inclination. In this work we investigate the fundamental relations between dust reddening and physical properties of galaxies, and obtain a well-defined empirical recipe for dust reddening. The empirical formulae can be incorporated into semi-analytical models of galaxy formation and evolution to estimate the dust reddening and facilitate comparison with observations.

scholarly journals Red supergiant stars in NGC 4449, NGC 5055, and NGC 5457

2016 ◽  
Vol 12 (S329) ◽  
pp. 392-392
Author(s):  
Sang-Hyun Chun ◽  
Yong-Jong Sohn ◽  
Martin Asplund ◽  
Luca Casagrande
Keyword(s):  
Galaxy Formation ◽  
Near Infrared ◽  
Massive Stars ◽  
H Ii Regions ◽  
Imaging Data ◽  
Spatially Correlated ◽  
Galaxy Formation And Evolution ◽  
Colour Distribution ◽  
Red Supergiants ◽  
Nearby Galaxies

AbstractNearby galaxies are ideal objects for the study of the mechanisms of galaxy formation and evolution, and massive stars in nearby galaxies are useful sources to investigate the structures and formation of the galaxies. It is important to gather the contents of massive stars for a number of galaxies spanning various metallicities. We focus on the red supergiants (RSGs) in nearby galaxies NGC 4449, NGC 5055, and NGC 5457, and the photometric properties of RSGs of three galaxies were investigated using near-infrared (JHK) imaging data obtained from WFCAM UKIRT. The (J − K, K)0 CMDs are investigated and compared with theoretical isochrones (Figure 1). The majority of RSGs in three galaxies have common age ranges from log(tyr) = 6.9 to log(tyr) = 7.3, and this indicates that these galaxies have experienced recent star formation within 20 Myr. Spatial correlation of RSGs with H II regions and their colour distribution were also investigated. For NGC 4449 and NGC 5457, the RSGs are spatially correlated with the H II regions, which however is not the case for NGC 5055. We found a similar colour distribution and a constant peak magnitude of MK = −11.9 for the RSGs in the three galaxies.

scholarly journals Radio-loud AGN in the first LoTSS data release

2019 ◽  
Vol 622 ◽  
pp. A12 ◽  
Author(s):  
M. J. Hardcastle ◽  
W. L. Williams ◽  
P. N. Best ◽  
J. H. Croston ◽  
K. J. Duncan ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Galactic Nuclei ◽  
Lifetime Distribution ◽  
Analytical Models ◽  
Jet Physics ◽  
Star Forming ◽  
Galaxy Formation And Evolution ◽  
Sky Survey ◽  
Formation And Evolution ◽  
Good Agreement

We constructed a sample of 23 344 radio-loud active galactic nuclei (RLAGN) from the catalogue derived from the LOFAR Two-Metre Sky Survey (LoTSS) survey of the HETDEX Spring field. Although separating AGN from star-forming galaxies remains challenging, the combination of spectroscopic and photometric techniques we used gives us one of the largest available samples of candidate RLAGN. We used the sample, combined with recently developed analytical models, to investigate the lifetime distribution of RLAGN. We show that large or giant powerful RLAGN are probably the old tail of the general RLAGN population, but that the low-luminosity RLAGN candidates in our sample, many of which have sizes < 100 kpc, either require a very different lifetime distribution or have different jet physics from the more powerful objects. We then used analytical models to develop a method of estimating jet kinetic powers for our candidate objects and constructed a jet kinetic luminosity function based on these estimates. These values can be compared to observational quantities, such as the integrated radiative luminosity of groups and clusters, and to the predictions from models of RLAGN feedback in galaxy formation and evolution. In particular, we show that RLAGN in the local Universe are able to supply all the energy required per comoving unit volume to counterbalance X-ray radiative losses from groups and clusters and thus prevent the hot gas from cooling. Our computation of the kinetic luminosity density of local RLAGN is in good agreement with other recent observational estimates and with models of galaxy formation.

The relationship between black hole accretion rate and gas properties at the Bondi radius

2019 ◽  
Vol 15 (S356) ◽  
pp. 214-217
Author(s):  
De-Fu Bu
Keyword(s):  
Black Hole ◽  
Galaxy Formation ◽  
Large Scale ◽  
Accretion Rate ◽  
Black Hole Accretion ◽  
Galaxy Formation And Evolution ◽  
Formation And Evolution ◽  
The Relationship ◽  
Large Scale Simulations ◽  
Hole Accretion

AbstractThe mass accretion rate determines the black hole accretion mode and the corresponding efficiency of active galactic nuclei (AGNs) feedback. In large-scale simulations studying galaxy formation and evolution, the Bondi radius can be at most marginally resolved. In these simulations, the Bondi accretion formula is always used to estimate the black hole accretion rate. The Bondi solution can not represent the real accretion process. We perform 77 simulations with varying density and temperature at Bondi radius. We find a formula to calculate the black hole accretion rate based on gas density and temperature at Bondi radius. We find that the formula can accurately predict the luminosity of observed low-luminosity AGNs. This formula can be used in sub-grid models in large-scale simulations with AGNs feedback.

scholarly journals Euclid: the selection of quiescent and star-forming galaxies using observed colours

2020 ◽  
Vol 494 (2) ◽  
pp. 2337-2354
Author(s):  
L Bisigello ◽  
U Kuchner ◽  
C J Conselice ◽  
S Andreon ◽  
M Bolzonella ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Rest Frame ◽  
Star Forming ◽  
Galaxy Formation And Evolution ◽  
Formation And Evolution ◽  
Selection Of ◽  
Key Questions

ABSTRACT The Euclid mission will observe well over a billion galaxies out to z ∼ 6 and beyond. This will offer an unrivalled opportunity to investigate several key questions for understanding galaxy formation and evolution. The first step for many of these studies will be the selection of a sample of quiescent and star-forming galaxies, as is often done in the literature by using well-known colour techniques such as the ‘UVJ’ diagram. However, given the limited number of filters available for the Euclid telescope, the recovery of such rest-frame colours will be challenging. We therefore investigate the use of observed Euclid colours, on their own and together with ground-based u-band observations, for selecting quiescent and star-forming galaxies. The most efficient colour combination, among the ones tested in this work, consists of the (u − VIS) and (VIS − J) colours. We find that this combination allows users to select a sample of quiescent galaxies complete to above $\sim 70{{\ \rm per\ cent}}$ and with less than 15${{\ \rm per\ cent}}$ contamination at redshifts in the range 0.75 &lt; z &lt; 1. For galaxies at high-z or without the u-band complementary observations, the (VIS − Y) and (J − H) colours represent a valid alternative, with $\gt 65{{\ \rm per\ cent}}$ completeness level and contamination below 20${{\ \rm per\ cent}}$ at 1 &lt; z &lt; 2 for finding quiescent galaxies. In comparison, the sample of quiescent galaxies selected with the traditional UVJ technique is only $\sim 20{{\ \rm per\ cent}}$ complete at z &lt; 3, when recovering the rest-frame colours using mock Euclid observations. This shows that our new methodology is the most suitable one when only Euclid bands, along with u-band imaging, are available.

scholarly journals A New Catalog of Isolated Galaxies

2009 ◽  
Vol 5 (S267) ◽  
pp. 464-464
Author(s):  
J. A. Vázquez-Mata ◽  
H. M. Hernández-Toledo ◽  
Changbom Park ◽  
Yun-Young Choi
Keyword(s):  
Galaxy Formation ◽  
Environmental Effects ◽  
Comparative Studies ◽  
Sloan Digital Sky Survey ◽  
Selection Algorithm ◽  
Isolated Galaxies ◽  
Galaxy Formation And Evolution ◽  
Sky Survey ◽  
Data Release ◽  
Formation And Evolution

We present a new catalog of isolated galaxies (coined as UNAM–KIAS) obtained through an automated systematic search. The 1520 isolated galaxies were found in ~ 1.4 steradians of the sky in the Sloan Digital Sky Survey Data Release 5 (SDSS DR5) photometry. The selection algorithm was implemented from a variation of the criteria developed by Karachentseva (1973), with full redshift information. This new catalog is aimed to carry out comparative studies of environmental effects and constraining the currently competing scenarios of galaxy formation and evolution.

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.

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