scholarly journals The Role of the Interstellar Medium in Galaxy Formation Simulations

2007 ◽  
Vol 24 ◽  
pp. 77-88 ◽  
Author(s):  
G.L. Bryan
Keyword(s):  
Interstellar Medium ◽  
Galaxy Formation

scholarly journals Simulating the interstellar medium of galaxies with radiative transfer, non-equilibrium thermochemistry, and dust

2020 ◽  
Vol 499 (4) ◽  
pp. 5732-5748 ◽  
Author(s):  
Rahul Kannan ◽  
Federico Marinacci ◽  
Mark Vogelsberger ◽  
Laura V Sales ◽  
Paul Torrey ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Galaxy Formation ◽  
State Of The Art ◽  
Complex Function ◽  
Ionization State ◽  
Radiation Fields ◽  
Stellar Feedback ◽  
Wide Range ◽  
Dust Distribution ◽  
Non Equilibrium

ABSTRACT We present a novel framework to self-consistently model the effects of radiation fields, dust physics, and molecular chemistry (H2) in the interstellar medium (ISM) of galaxies. The model combines a state-of-the-art radiation hydrodynamics module with a H  and He  non-equilibrium thermochemistry module that accounts for H2 coupled to an empirical dust formation and destruction model, all integrated into the new stellar feedback framework SMUGGLE. We test this model on high-resolution isolated Milky-Way (MW) simulations. We show that the effect of radiation feedback on galactic star formation rates is quite modest in low gas surface density galaxies like the MW. The multiphase structure of the ISM, however, is highly dependent on the strength of the interstellar radiation field. We are also able to predict the distribution of H2, that allow us to match the molecular Kennicutt–Schmidt (KS) relation, without calibrating for it. We show that the dust distribution is a complex function of density, temperature, and ionization state of the gas. Our model is also able to match the observed dust temperature distribution in the ISM. Our state-of-the-art model is well-suited for performing next-generation cosmological galaxy formation simulations, which will be able to predict a wide range of resolved (∼10 pc) properties of galaxies.

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.

scholarly journals The Role of the Parker Instability in Structuring the Interstellar Medium

2020 ◽  
Vol 891 (2) ◽  
pp. 157 ◽  
Author(s):  
Evan Heintz ◽  
Chad Bustard ◽  
Ellen G. Zweibel
Keyword(s):  
Interstellar Medium

scholarly journals First Results from the Submillimeter Wave Astronomy Satellite – H2O and O2 Discoveries

2000 ◽  
Vol 197 ◽  
pp. 161-174
Author(s):  
Gary J. Melnick
Keyword(s):  
Interstellar Medium ◽  
Ground State ◽  
Molecular Clouds ◽  
Submillimeter Wave ◽  
Important Species ◽  
First Results ◽  
One Year

The Submillimeter Wave Astronomy Satellite (SWAS) was successfully launched on 5 December 1998 with the goals of studying: (1) the distribution of oxygen in the interstellar medium; (2) the role of H2O and O2 as gas coolants; and (3) the UV-illuminated surfaces of molecular clouds. To achieve these goals, SWAS is conducting pointed observations of dense (n(H2) > 103 cm–3) molecular clouds throughout our Galaxy in either the ground-state or a low-lying transition of five astrophysically important species: H2O, H218O, O2, CI, and 13CO. SWAS has made great strides in each of these areas of investigation. This paper will summarize our H2O and O2 findings one year into the mission.

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

scholarly journals The 12C/13C Ratio in Interstellar Dark Clouds

1980 ◽  
Vol 87 ◽  
pp. 411-416
Author(s):  
W.H. Mccutcheon ◽  
R. L. Dickman ◽  
W.L.H. Shuter ◽  
R. S. Roger
Keyword(s):  
Radiative Transfer ◽  
Interstellar Medium ◽  
Stellar Evolution ◽  
Transfer Problem ◽  
Abundance Ratio ◽  
Radiative Transfer Problem ◽  
Dark Clouds ◽  
Non Equilibrium

Since 13C is believed to be produced by non-equilibrium CNO processing in stellar evolution (Truran 1977), measurements of the carbon ratio Rc ≡ [12C] / [13C] in the interstellar medium may provide important information on nucleo-synthesis. Commonly, the ratio (N13/N18)LTE ≡ [13CO/C18O]LTE is measured and from this RLTE ≡ [12CO/13CO]LTE is deduced and these values are often identified with Rc. However, this line of reasoning can be misleading for two reasons (Dickman et al. 1979):(1) The difficulty of determining accurate column densities, [13C16O] and [12C18O], because of the complexity of the radiative transfer problem;(2) The possible role of fractionation, whereby RCO ≡ [12CO] / [13CO] does not necessarily reflect the initial atomic abundance ratio RC (Watson et al. 1976, Langer 1977, Liszt 1978).

scholarly journals Sh 2-68 – A Planetary Nebula Leaving it's Mark on the Interstellar Medium

2003 ◽  
Vol 209 ◽  
pp. 525-526 ◽  
Author(s):  
F. Kerber ◽  
F. Guglielmetti ◽  
R. Mignani ◽  
M. Roth
Keyword(s):  
Interstellar Medium ◽  
Planetary Nebula ◽  
Galactic Disk ◽  
Central Star ◽  
Main Body ◽  
Left Behind ◽  
Sky Survey ◽  
Cometary Tail ◽  
Direct Confirmation

Using Hα images from the Southern H-Alpha Sky Survey Atlas (SHASSA) we have discovered a “cometary tail” of ionized matter extending at least 30 arcmin from the main body of the planetary nebula Sh 2-68 (PN G030.6+06.2). This tail is aligned with the proper motion of the central star and is obviously a contrail of material left behind by Sh 2-68 moving in a Galactic Disk orbit. The tail's existence is a direct confirmation of Sh 2-68's interaction with the interstellar medium (ISM) and highlights the possibly important role of the ISM's magnetic field.

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.

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