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Related papers: Does the CO-to-H2 conversion factor depend on the …

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We present $^{12}$CO(1-0) and $^{12}$CO(2-1) observations of a sample of 20 star-forming dwarfs selected from the Herschel Virgo Cluster Survey, with oxygen abundances ranging from 12 + log(O/H) ~ 8.1 to 8.8. CO emission is observed in ten…

We investigate the dependence of stellar properties on the initial kinematic structure of the gas in star-forming molecular clouds. We compare the results from two large-scale hydrodynamical simulations of star cluster formation that…

Solar and Stellar Astrophysics · Physics 2015-05-13 Matthew R. Bate

We use vertically-resolved numerical hydrodynamic simulations to study star formation and the interstellar medium (ISM) in galactic disks. We focus on outer disk regions where diffuse HI dominates, with gas surface densities Sigma_SFR=3-20…

Astrophysics of Galaxies · Physics 2015-05-30 Chang-Goo Kim , Woong-Tae Kim , Eve C. Ostriker

Using the atomic carbon [CI](1$-$0) and [CI](2$-$1) emission maps observed with the $Herschel\ Space\ Observatory$, and CO(1$-$0), HI, infrared and submm maps from literatures, we estimate the [CI]-to-H$_2$ and CO-to-H$_2$ conversion…

Astrophysics of Galaxies · Physics 2021-04-28 Qian Jiao , Yu Gao , Yinghe Zhao

The formation and mass distribution of the first stars depend on various environmental factors in the early universe. We compare 120 cosmological hydrodynamical simulations to explore how the baryonic streaming velocity (SV) relative to…

Astrophysics of Galaxies · Physics 2025-05-12 Shingo Hirano

We examine spatial variations of the C$^0$/CO abundance ratio ($X_{\mathrm{C/CO}}$) in the vicinity of the $\gamma$-ray supernova remnant W51C, based on [CI] ($^3P_1$-$^3P_0$), $^{12}$CO(1-0), and $^{13}$CO(1-0) observations with the ASTE…

The Star Formation (SF) rate in galaxies is an important parameter at all redshifts and evolutionary stages of galaxies. In order to understand the increased SF rates in intermediate redshift galaxies one possibility is to study star…

Astrophysics · Physics 2009-11-13 E. Gardan , J. Braine , K. F. Schuster , N. Brouillet , A. Sievers

We used three indicators of massive star formation: $H_{\alpha}$, FIR and non-thermal radio luminosities, to compare estimations of Star Formation Rate (SFR) for the sample of 34 spiral galaxies. To adjust SFR values, obtained from…

Astrophysics · Physics 2009-10-31 D. V. Bizyaev

Does star formation proceed in the same way in large spirals such as the Milky Way and in smaller chemically younger galaxies? Earlier work suggests a more rapid transformation of H$_2$ into stars in these objects but (1) a doubt remains…

Astrophysics of Galaxies · Physics 2016-04-20 Jonathan Braine , Pierre Gratier , Carsten Kramer , Karl F. Schuster , Fatemeh Tabatabaei , Erwan Gardan

Properties of CFRS field galaxies up to z=1 are discussed. Estimations of the cosmic star formation rate (SFR) lead to serious problems if they not account for AGN emissions and for light reemitted at IR wavelengths. Deep ISOCAM and VLA…

Astrophysics · Physics 2007-05-23 F. Hammer , H. Flores

In the redshift interval of $2<z<3$, the physical conditions of the inter-stellar medium (ISM) in star-forming galaxies are likely to be different from those in the local Universe because of lower gaseous metallicities, higher gas…

Studies both of entire galaxies and of local Galactic star formation indicate a dependency of a molecular cloud's star formation rate (SFR) on its dense gas mass. In external galaxies, such measurements are derived from HCN(1-0)…

Astrophysics of Galaxies · Physics 2018-02-14 S. Viaene , J. Forbrich , J. Fritz

The relationship between the star formation rate and surface density of neutral gas within the disk of M33 is examined with new imaging observations of CO J=1-0 emission gathered with the FCRAO 14m telescope and IRAS HiRes images of the 60…

Astrophysics · Physics 2009-11-10 M. H. Heyer , E. Corbelli , S. E. Schneider , J. S. Young

We construct a semi-analytic model to study the effect of far-ultraviolet (FUV) radiation on gas chemistry from embedded protostars. We use the Protostellar Luminosity Function (PLF) formalism of Offner & McKee (2011) to calculate the…

Astrophysics of Galaxies · Physics 2018-02-28 Brandt A. L. Gaches , Stella S. R. Offner

In this study, we present a suite of high-resolution numerical simulations of an isolated galaxy to test a sub-grid framework to consistently follow the formation and dissociation of H$_2$ with non-equilibrium chemistry. The latter is…

Astrophysics of Galaxies · Physics 2017-12-27 Alessandro Lupi , Stefano Bovino , Pedro R. Capelo , Marta Volonteri , Joseph Silk

The $^{13}$CO molecule is often used as a column density tracer in regions where the $^{12}$CO emission saturates. The $^{13}$CO column density is then related to that of $^{12}$CO by a uniform isotopic ratio. A similar approximation is…

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

In the earliest phases of star-forming clouds, stable molecular species, such as CO, are important coolants in the gas phase. Depletion of these molecules on dust surfaces affects the thermal balance of molecular clouds and with that their…

Astrophysics of Galaxies · Physics 2016-01-27 S. Hocuk , S. Cazaux , M. Spaans , P. Caselli

We seek to derive star formation rates (SFR) and stellar masses (M_star) in distant galaxies and to quantify the main uncertainties affecting their measurement. We explore the impact of the assumptions made in their derivation with standard…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 V. Buat , S. Heinis , M. Boquien , D. Burgarella , V. Charmandaris , S. Boissier , A. Boselli , D. Le Borgne , G. Morrison

We present a new survey of HCN(1-0) emission, a tracer of dense molecular gas, focused on the little-explored regime of normal star-forming galaxy disks. Combining HCN, CO, and infrared (IR) emission, we investigate the role of dense gas in…

The CO-to-H$_2$ conversion factor ($\alpha_\rm{CO}$) is central to measuring the amount and properties of molecular gas. It is known to vary with environmental conditions, and previous studies have revealed lower $\alpha_\rm{CO}$ in the…