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Related papers: The CO-H2 Conversion Factor in Galaxy Mergers

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The faint CO gases in debris disks are easily dissolved into C by UV irradiation, while CO can be reformed via reactions with hydrogen. The abundance ratio of C/CO could thus be a probe of the amount of hydrogen in the debris disks. We…

Earth and Planetary Astrophysics · Physics 2023-06-14 Kazunari Iwasaki , Hiroshi Kobayashi , Aya E. Higuchi , Yuri Aikawa

We study the evolution of the cold gas content of galaxies by splitting the interstellar medium into its atomic and molecular hydrogen components, using the galaxy formation model GALFORM in the LCDM framework. We calculate the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Claudia del P. Lagos , Carlton M. Baugh , Cedric G. Lacey , Andrew J. Benson , Han-Seek Kim , Chris Power

Galaxy merging is the late time manifestation of the galaxy formation process and likely significantly effects $z<1$ galaxies. A ``maximum reasonable rate'' model for merging finds a $\sim2$ mag K band increase in the luminosities of dwarf…

Astrophysics · Physics 2016-08-30 R. G. Carlberg

The star formation rate history of galactic objects in hydrodynamical cosmological simulations are analyzed in relation to their merger histories. The findings suggest that massive mergers produce more efficient starbursts and that,…

Astrophysics · Physics 2007-05-23 Patricia B. Tissera

Using the Atacama Large Millimeter/submillimeter Array, we have made the first high spatial and spectral resolution observations of the molecular gas and dust in the prototypical blue compact dwarf galaxy II Zw 40. The CO(2-1) and CO(3-2)…

Astrophysics of Galaxies · Physics 2016-09-07 Amanda A. Kepley , Adam K. Leroy , Kelsey E. Johnson , Karin Sandstrom , C. -H. Rosie Chen

We present evidence that super giant HII regions (GHRs) and other disk regions of the nearby spiral galaxy, M33, occupy distinct locations in the correlation between molecular gas, $\Sigma_{\rm H_2}$, and the star formation rate surface…

We model the effect of grain size distribution in a galaxy on the evolution of CO and H$_2$ abundances. The formation and dissociation of CO and H$_2$ in typical dense clouds are modelled in a manner consistent with the grain size…

Astrophysics of Galaxies · Physics 2023-05-10 Hiroyuki Hirashita

We study the impact of different galaxy statistics and empirical metallicity scaling relations on the merging rates and on the properties of compact objects binaries. First, we analyze the similarities and differences of using the star…

Astrophysics of Galaxies · Physics 2021-02-17 Lumen Boco , Andrea Lapi , Martyna Chruslinska , Darko Donevski , Alex Sicilia , Luigi Danese

In their final stages before undergoing a core-collapse supernova, massive stars may experience mergers between internal shells where carbon (C) and oxygen (O) are consumed as fuels for nuclear burning. This interaction, known as a C-O…

Solar and Stellar Astrophysics · Physics 2025-06-18 L. Roberti , M. Pignatari , H. E. Brinkman , S. K. Jeena , A. Sieverding , A. Falla , M. Limongi , A. Chieffi , M. Lugaro

Carbon monoxide (CO) emission is the most widely used tracer of the bulk molecular gas in the interstellar medium (ISM) in extragalactic studies. The CO-to-H$_2$ conversion factor, $\alpha_{\rm CO}$, links the observed CO emission to the…

The process of galaxy evolution over cosmic time is not yet fully understood, since there is a debate on the impact of galaxy collisions on the star formation and metallicity. The local environment of the galaxy mergers could also have a…

Astrophysics of Galaxies · Physics 2025-09-12 Bendeguz Koncz , Istvan Horvath , András Péter Joó , Andreas Burkert , L. Viktor Tóth

We have undertaken numerical simulations of galaxy interactions and mergers, coupling the dynamics with the star formation history and the chemical evolution. The self-gravity of stars and gas is taken into account through a tree-code…

Astrophysics · Physics 2009-11-07 F. Combes , A. L. Melchior

As the formation of cosmic structure continues to proceed, we observe one of the latest stages of this process in mergers of clusters of galaxies with other clusters, groups, and galaxies. The X-ray emitting hot plasma of these systems can…

High Energy Astrophysical Phenomena · Physics 2023-04-05 John ZuHone , Yuanyuan Su

In this study, we used the 13.7m telescope at Qinghai Station to observe CO data in 48 galaxies in Virgo clusters, of which 41 sources observed CO signals. The properties of molecular gas are deduced by co-to-$H_2$ factor. We also collected…

Astrophysics of Galaxies · Physics 2025-03-11 ZhiYong Hu , JingFu Hu , YiPing Ao

Collisions between giant molecular clouds (GMCs) have been proposed as a mechanism to trigger massive star and star cluster formation. To investigate the astrochemical signatures of such collisions, we carry out 3D magnetohydrodynamics…

Astrophysics of Galaxies · Physics 2023-08-24 Chia-Jung Hsu , Jonathan C. Tan , Jonathan Holdship , Duo , Xu , Serena Viti , Benjamin Wu , Brandt Gaches

Results from hydrodynamical SPH simulations of galaxy clusters are used to investigate the dependence of the final cluster X-ray properties on the numerical resolution and the assumed models for the physical gas processes. Two different…

Astrophysics · Physics 2009-11-07 R. Valdarnini

We study the CO(1-0)-to-H$_2$ conversion factor ($X_{\rm CO}$) and the line ratio of CO(2-1)-to-CO(1-0) ($R_{21}$) across a wide range of metallicity ($0.1 \leq Z/Z_\odot \leq 3$) in high-resolution (~0.2 pc) hydrodynamical simulations of a…

Astrophysics of Galaxies · Physics 2022-06-01 Chia-Yu Hu , Andreas Schruba , Amiel Sternberg , Ewine F. van Dishoeck

We present a new model to describe the star formation process in galaxies, which includes the description of the different gas phases -- molecular, atomic, and ionized -- together with its metal content. The model, which will be coupled to…

Astrophysics of Galaxies · Physics 2025-08-14 Ezequiel Lozano , Cecilia Scannapieco , Sebastian E. Nuza

The bulk of the molecular gas in spiral galaxies is under the form of cold H2, that does not radiate and is only suspected through tracer molecules, such as CO. All tracers are biased, and in particular H2 could be highly underestimated in…

Astrophysics · Physics 2007-05-23 F. Combes

In this paper, we investigate the conditions for the HI-to-H$_{2}$ transition in the solar neighborhood by analyzing HI emission and absorption measurements toward 58 Galactic lines of sight (LOSs) along with $^{12}$CO(1$-$0) (CO) and dust…