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Related papers: The X-factor in Galaxies: I. Dependence on Environ…

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We estimate the conversion factor relating CO emission to H2 mass, alpha_CO, in five Local Group galaxies that span approximately an order of magnitude in metallicity - M31, M 33, the Large Magellanic Cloud (LMC), NGC 6822, and the Small…

We use a 0.040 < z < 0.085 sample of 37866 star-forming galaxies from the Fourth Data Release of the Sloan Digital Sky Survey to investigate the dependence of gas-phase chemical properties on stellar mass and environment. The local density,…

Astrophysics · Physics 2009-06-23 M. Mouhcine , I. K. Baldry , S. P. Bamford

We utilize a modified astrochemistry code which includes cosmic ray attenuation in-situ to quantify the impact of different cosmic-ray models on the CO-to-H$_2$ and CI-to-H$_2$ conversion factors, $X_{\rm CO}$ and $X_{\rm CI}$,…

Astrophysics of Galaxies · Physics 2019-10-09 Brandt A. L. Gaches , Stella S. R. Offner , Thomas G. Bisbas

In a previous paper, we calculated numerical hydrodynamic models of the interstellar medium in the Galaxy, which suggested that hot gas (T $\ge$ 3 $\times$ 10$^5$ K) has a filling factor near 50\% in the midplane (Rosen \& Bregman 1995, ApJ…

Astrophysics · Physics 2009-10-28 Alexander Rosen , Joel N. Bregman , Daniel D. Kelson

Tracing molecular hydrogen content with carbon monoxide in low-metallicity galaxies has been exceedingly difficult. Here we present a new effort, with IRAM 30-m observations of 12CO(1-0) of a sample of 8 dwarf galaxies having oxygen…

Astrophysics of Galaxies · Physics 2015-11-04 L. K. Hunt , S. Garcia-Burillo , V. Casasola , P. Caselli , F. Combes , C. Henkel , A. Lundgren , R. Maiolino , K. M. Menten , L. Testi , A. Weiss

Molecular abundances in protoplanetary disks are highly sensitive to the local physical conditions, including gas temperature, gas density, radiation field, and dust properties. Often multiple factors are intertwined, impacting the…

Earth and Planetary Astrophysics · Physics 2023-12-11 Amina Diop , Ilse Cleeves , Dana Anderson , Jamila Pegues , Adele Plunkett

We study the effects of the local environment on the molecular gas content of a large sample of log($M_{*}$/$M_{\odot}$) $\gtrsim$ 10 star-forming and starburst galaxies with specific star-formation rates (sSFRs) on and above the main…

Astrophysics of Galaxies · Physics 2020-06-16 Behnam Darvish , Nick Z. Scoville , Christopher Martin , Bahram Mobasher , Tanio Diaz-Santos , Lu Shen

In this review, I discuss some highlights of recent research on molecular gas in galaxies; large-scale CO maps of nearby galaxies are being made, which extend our knowledge on global properties, radial gradients, and spiral structure of the…

Astrophysics · Physics 2016-08-30 F. Combes

A primary goal of characterizing exoplanet atmospheres is to constrain planetary bulk properties, such as their metallicity, C/O ratio, and intrinsic heat. However, there are significant uncertainties in many aspects of atmospheric physics,…

Earth and Planetary Astrophysics · Physics 2024-10-23 Sagnick Mukherjee , Jonathan J. Fortney , Nicholas F. Wogan , David K. Sing , Kazumasa Ohno

In this work we present an analysis of the behaviour of galaxies in a four-dimensional parameter space defined by stellar mass, metallicity, star formation rate, and molecular gas mass. We analyse a combined sample of 227 galaxies, which…

Astrophysics of Galaxies · Physics 2016-10-26 M. S. Bothwell , R. Maiolino , C. Cicone , Y. Peng , J. Wagg

We measure and analyze galaxy clustering and the dependence on luminosity, color, age, stellar mass and specific star formation rate using Baryon Oscillation Spectroscopic Survey (BOSS) galaxies at $0.48<z<0.62$. We fit the monopole and…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-18 Zhongxu Zhai , Will J. Percival , Hong Guo

We present numerical simulations of molecular clouds (MCs) with self-consistent CO gas-phase and isotope chemistry in various environments. The simulations are post-processed with a line radiative transfer code to obtain $^{12}$CO and…

Astrophysics of Galaxies · Physics 2016-04-25 László Szűcs , Simon C. O. Glover , Ralf S. Klessen

Recent observational results indicate that the functional shape of the spatially-resolved star formation-molecular gas density relation depends on the spatial scale considered. These results may indicate a fundamental role of sampling…

Astrophysics of Galaxies · Physics 2015-06-04 Daniela Calzetti , Guilin Liu , Jin Koda

The advent of new sub-millimeter observational facilities has stimulated the desire to model the sub-mm line emission of galaxies within cosmological galaxy formation models. This is typically done in post-processing by applying…

Astrophysics of Galaxies · Physics 2018-11-14 Gergö Popping , Desika Narayanan , Rachel S. Somerville , Andreas L. Faisst , Mark R. Krumholz

Galaxy morphologies and star-formation rates depend on environment. Galaxies in under-dense regions are generally star-forming and disky whereas galaxies in overdense regions tend to be early-type and not actively forming stars. The…

Astrophysics of Galaxies · Physics 2015-11-04 Ian D. Roberts , Laura C. Parker , Ananthan Karunakaran

The specific star-formation rate of star-forming `main sequence' galaxies significantly decreased since z~1.5, due to the decreasing molecular gas fraction and star formation efficiency. However, the radio-infrared (IR) correlation has not…

Astrophysics of Galaxies · Physics 2025-01-29 B. Vollmer , J. Freundlich , P. Gratier , Th. Lizee , M. Lendrin , J. Braine , M. Soida

The abundance of galaxy clusters as a function of mass and redshift is a well known powerful cosmological probe, which relies on underlying modelling assumptions on the mass-observable relations (MOR). Some of the MOR parameters can be…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-22 Priyanka Singh , Alex Saro , Matteo Costanzi , Klaus Dolag

The CO-to-H$_2$ conversion factor ($\alpha_\mathrm{CO}$) is expected to vary with dust abundance and grain size distribution through the efficiency of shielding gas from CO-dissociation radiation. We present a comprehensive analysis of…

Using hydrodynamical simulations of a Milky Way-like galaxy, reaching 4.6 pc resolution, we study how the choice of star formation criteria impacts both galactic and Giant Molecular Clouds (GMC) scales. We find that using a turbulent,…

Astrophysics of Galaxies · Physics 2020-11-25 Kearn Grisdale

The abundance evolution of galaxies depends critically on the balance between the mixing of metals in their interstellar medium, the inflow of new gas and the outflow of enriched gas. We study these processes in gas columns perpendicular to…

Astrophysics of Galaxies · Physics 2015-06-23 Peter Creasey , Tom Theuns , Richard G. Bower
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