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We utilize observations of sub-millimeter rotational transitions of CO from a Herschel Cycle 2 open time program ("COPS", PI: J. Green) to identify previously predicted turbulent dissipation by magnetohydrodynamic (MHD) shocks in molecular…

星系天体物理 · 物理学 2022-03-17 Rebecca L. Larson , Neal J. Evans , Joel D. Green , Yao-Lun Yang

We present the second dust continuum data release in the Census of High- and Medium-mass Protostars (CHaMP), expanding the methodology trialed in Pitts et al. 2019 to the entire CHaMP survey area ($280^{\circ}<l<300^{\circ}$,…

星系天体物理 · 物理学 2021-08-25 Rebecca L. Pitts , Peter J. Barnes

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…

星系天体物理 · 物理学 2016-04-20 Jonathan Braine , Pierre Gratier , Carsten Kramer , Karl F. Schuster , Fatemeh Tabatabaei , Erwan Gardan

We revisit the mass ratio Rmol between molecular hydrogen (H2) and atomic hydrogen (HI) in different galaxies from a phenomenological and theoretical viewpoint. First, the local H2-mass function (MF) is estimated from the local…

星系天体物理 · 物理学 2009-07-17 D. Obreschkow , S. Rawlings

An overview is given of the chemical processes that occur in primordial systems under the influence of radiation, metal abundances and dust surface reactions. It is found that radiative feedback effects differ for UV and X-ray photons at…

天体物理学 · 物理学 2009-11-13 M. Spaans

We present 3D "zoom-in" simulations of the formation of two molecular clouds out of the galactic interstellar medium. We model the clouds - identified from the SILCC simulations - with a resolution of up to 0.06 pc using adaptive mesh…

星系天体物理 · 物理学 2017-10-18 D. Seifried , S. Walch , P. Girichidis , T. Naab , R. Wünsch , R. S. Klessen , S. C. O. Glover , T. Peters , P. Clark

Many recent models consider the structure of individual interstellar medium (ISM) clouds as a way to explain observations of large parts of galaxies. To compare such models to observations, one must understand how to translate between…

宇宙学与河外天体物理 · 物理学 2015-06-15 Adam K. Leroy , Cheoljong Lee , Andreas Schruba , Alberto Bolatto , Annie Hughes , Jerome Pety , Karin Sandstrom , Eva Schinnerer , Fabian Walter

We report the first ensemble results from the FUSE survey of molecular hydrogen in lines of sight with A_V $\gtrsim$ 1 mag. We have developed techniques for fitting computed profiles to the low-J lines of H2, and thus determining column…

Aims. We present a new sub-grid model, HYACINTH -- HYdrogen And Carbon chemistry in the INTerstellar medium in Hydro simulations -- for computing the non-equilibrium abundances of ${\rm H_2}$ and its carbon-based tracers, namely ${\rm CO}$,…

星系天体物理 · 物理学 2024-07-02 Prachi Khatri , Cristiano Porciani , Emilio Romano-Díaz , Daniel Seifried , Alexander Schäbe

We aim to better understand how the spatial structure of molecular clouds is governed by turbulence. For that, we study the large-scale spatial distribution of low density molecular gas and search for characteristic length scales. We employ…

星系天体物理 · 物理学 2015-05-18 N. Schneider , S. Bontemps , R. Simon , V. Ossenkopf , C. Federrath , R. Klessen , F. Motte , P. Andre , J. Stutzki , C. Brunt

After the recombination of Hydrogen, primordial molecules such as H_2, $HD$ can be formed.The formation of structures in the post-recombination gaseous medium is commonly explained by primordial density fluctuations. In a self-gravitating…

天体物理学 · 物理学 2007-05-23 D. Puy , M. Signore

Molecular hydrogen being unobservable in cold molecular clouds, the column density measurements of molecular gas currently rely either on dust emission observation in the far-IR or on star counting. (Sub-)millimeter observations of numerous…

We present the analysis of a sub-DLA system (log N(H^0)=20.0+/-0.15, z_abs=2.69) toward SDSS J123714+064759 (z_em=2.78). Using the VLT/UVES and X-shooter spectrographs, we detect H2, HD and CO molecules in absorption with log…

宇宙学与河外天体物理 · 物理学 2015-05-19 P. Noterdaeme , P. Petitjean , C. Ledoux , S. Lopez , R. Srianand , S. D. Vergani

Context: Dark cloud chemical models usually predict large amounts of O2, often above observational limits. Aims: We investigate the reason for this discrepancy from a theoretical point of view, inspired by the studies of Jenkins and Whittet…

太阳与恒星天体物理 · 物理学 2012-11-16 U. Hincelin , V. Wakelam , F. Hersant , S. Guilloteau , J. C. Loison , P. Honvault , J. Troe

We use high spatial resolution observations of CO to systematically measure the resolved size-line width, luminosity-line width, luminosity-size, and the mass-luminosity relations of Giant Molecular Clouds (GMCs) in a variety of…

天体物理学 · 物理学 2009-11-13 Alberto D. Bolatto , Adam K. Leroy , Erik Rosolowsky , Fabian Walter , Leo Blitz

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…

太阳与恒星天体物理 · 物理学 2014-11-20 S. Hocuk , M. Spaans

We study a population of significantly sub-solar enrichment galaxies at z=1.99, to investigate how molecular gas, dust and star-formation relate in low-metallicity galaxies at the peak epoch of star-formation. We target our sample with…

星系天体物理 · 物理学 2019-02-20 R. T. Coogan , M. T. Sargent , E. Daddi , F. Valentino , V. Strazzullo , M. Béthermin , R. Gobat , D. Liu , G. Magdis

Molecular hydrogen (H$_2$) formation and dissociation are key processes that drive the gas lifecycle in galaxies. Using the SImulating the LifeCycle of Molecular Clouds (SILCC) zoom-in simulation suite, we explore the utility of future…

Cold atomic and molecular gas are commonly observed in the winds of both external galaxies and the Milky Way, yet the survival and origin of these cool phases within hot galactic winds is poorly understood. To help gain insight into these…

We demonstrate that ionization of $\text{H}_2$ by dark matter in dense molecular clouds can provide strong constraints on the scattering strength of dark matter with electrons. Molecular clouds have high UV-optical attenuation, shielding…

高能物理 - 唯象学 · 物理学 2023-08-28 Anirudh Prabhu , Carlos Blanco