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Related papers: Metallicity effects in Photon Dominated Regions: C…

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The local cosmic-ray (CR) spectra are calculated for typical characteristic regions of a cold dense molecular cloud, to investigate two so far neglected mechanisms of dust charging: collection of suprathermal CR electrons and protons by…

Astrophysics of Galaxies · Physics 2015-11-05 Alexei Ivlev , Marco Padovani , Daniele Galli , Paola Caselli

Cosmic rays are appealing as a source of ionization in starburst galaxies because of the great columns they can penetrate, but in the densest regions of starbursts, they may be stopped by pion production and ionization energy losses. I…

High Energy Astrophysical Phenomena · Physics 2012-04-13 Brian C. Lacki

We report the statistical properties of stars and brown dwarfs obtained from four radiation hydrodynamical simulations of star cluster formation, the metallicities of which span a range from 1/100 to 3 times the solar value. Unlike previous…

Solar and Stellar Astrophysics · Physics 2019-01-15 Matthew R. Bate

Context: Molecular data of extreme environments, such as Arp 220, but also NGC 253, show evidence for extremely high cosmic ray (CR) rates (10^3-10^4 * Milky Way) and mechanical heating from supernova driven turbulence. Aims: The…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 R. Meijerink , M. Spaans , A. F. Loenen , P. P. van der Werf

We analyse the presence of dust around galaxy group members through the reddening of background quasars. By taking into account quasar colour and their dependence on redshift and angular position, we derive mean quasar colours excess in…

Astrophysics of Galaxies · Physics 2020-01-15 S. Rodríguez , D. Garcia Lambas , N. D. Padilla , P. Troncoso-Iribarren

We explore how environment affects the metallicity of the circumgalactic medium (CGM) using 13 low mass galaxy groups (2-5 galaxies) at $\langle z_{abs}\rangle=0.25$ identified near background quasars. Using quasar spectra from HST/COS and…

In this work we have assumed a Hernquist model with an inside-out formation for the Galactic bulge and, using a chemical evolution model, we were able obtain the bulge metallicity distribution function (MDF) for different radial regions.…

Astrophysics of Galaxies · Physics 2017-12-06 O. Cavichia , M. Mollá

(Abridged) The 30 Dor region in the Large Magellanic Cloud (LMC) is the most vigorous star-forming region in the Local Group. Star formation in this region is taking place in low-metallicity molecular gas that is exposed to an extreme…

Astrophysics of Galaxies · Physics 2015-06-05 Jorge L. Pineda , Norikazu Mizuno , Markus Roellig , Juergen Stutzki , Carsten Kramer , Ulrich Klein , Monica Rubio

We present for the first time a detailed study of the properties of molecular gas in metal-rich environments such as early-type galaxies (ETGs). We have explored Photon-Dominated Region (PDR) chemistry for a wide range of physical…

Astrophysics of Galaxies · Physics 2015-06-05 E. Bayet , T. A. Davis , T. A. Bell , S. Viti

According to the now strongly supported concordance $\Lambda$CDM model, galaxies may be grossly described as a luminous component embedded in a dark matter halo. The density profile of these mass dominating haloes may be determined by N -…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-04 A. Del Popolo , V. F. Cardone

We present metal abundances in 15 damped Lyman alpha systems (DLAs) from the Complete Optical and Radio Absorption Line System (CORALS) survey, designed to be free from any biasing effects due to extinction of QSOs by dust in intervening…

Astrophysics · Physics 2009-11-11 Chris J. Akerman , Sara L. Ellison , Max Pettini , Charles C. Steidel

(Abridged) We study the effects of interstellar clouds on the dynamical and chemical evolution of gas-rich dwarf galaxies. In particular, we focus on two model galaxies similar to IZw18 and NGC1569 in comparison to models in which a smooth…

Astrophysics · Physics 2009-11-13 S. Recchi , G. Hensler

In the past, the cumulative metallicity distribution function (CMDF) turned out as a useful tool to constrain the accretion history of various components of the Milky Way. In this Letter, by means of analytical, leaky-box chemical evolution…

Astrophysics of Galaxies · Physics 2021-04-21 E. Spitoni , F. Calura , V. Silva Aguirre , R. Gilli

We analyse the stellar mass-metallicity (M-Z) and stellar mass-star formation rate (M-SFR) relations for star-forming galaxies classified by their environment and compare them with matched control samples of field galaxies. Using data from…

Properties of candidate stars, forming out of molecular clouds, depend on the ambient conditions of the parent cloud. We present a series of 2D and 3D simulations of fragmentation of molecular clouds in starburst regions as well as clouds…

Solar and Stellar Astrophysics · Physics 2014-11-20 S. Hocuk , M. Spaans

Aims: Molecular emission lines originating in the nuclei of luminous infra-red galaxies are used to determine the physical properties of the nuclear ISM in these systems. Methods: A large observational database of molecular emission lines…

Astrophysics · Physics 2008-08-20 A. F. Loenen , M. Spaans , W. A. Baan , R. Meijerink

Seyfert narrow line region (NLR) emission line ratios are remarkably uniform, displaying only ~0.5 dex variation between galaxies, and even less within an individual object. Previous photoionization and shock models of this region were…

Astrophysics · Physics 2009-11-10 Brent A. Groves , Michael A. Dopita , Ralph S. Sutherland

We present a formalism for continuum and line emission from random clumpy media together with its application to problems of current interest, including CO spectral lines from ensembles of clouds and radio emission from HII regions,…

Astrophysics of Galaxies · Physics 2018-10-10 John E. Conway , Moshe Elitzur , Rodrigo Parra

The fractal structure of the interstellar medium suggests that the interaction of UV radiation with the ISM as described in the context of photon-dominated regions (PDR) dominates most of the physical and chemical conditions, and hence the…

Astrophysics · Physics 2009-11-13 M. Cubick , J. Stutzki , V. Ossenkopf , C. Kramer , M. Röllig

In this work, we aim at providing a consistent analysis of the dust properties from metal-poor to metal-rich environments by linking them to fundamental galactic parameters. We consider two samples of galaxies: the Dwarf Galaxy Survey (DGS)…

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