English
Related papers

Related papers: H2 distribution during 2-phase Molecular Cloud For…

200 papers

We examine the formation of molecular gas behind shocks in atomic gas using a chemical/dynamical model, particular emphasis is given to constraints the chemistry places on the dynamical evolution. The most important result of this study is…

We present the detection analysis of a diffuse molecular cloud at z$_{abs}$=2.4636 towards the quasar SDSS J1513+0352(z$_{em}\,\simeq$ 2.68) observed with the X-shooter spectrograph(VLT). We measure very high column densities of atomic and…

Molecular hydrogen (H$_2$) plays a critical role in astrophysical processes from galaxy evolution to the formation of planets. While the dominant formation channel in the interstellar medium is considered as dust-catalyzed H$_2$ formation,…

Astrophysics of Galaxies · Physics 2025-11-17 Xiaolong Yang , Lile Wang , Di Li , Shenzhen Xu

Context. Sulfur is used as a tracer of the evolution from interstellar clouds to stellar systems. However, most of the expected sulfur in molecular clouds remains undetected. Sulfur disappears from the gas phase in two steps. One first…

Astrophysics of Galaxies · Physics 2022-01-19 S. Cazaux , H. Carrascosa , G. M. Munoz Caro , P. Caselli , A. Fuente , D. Navarro-Almaida , P. Riviére-Marichalar

Recent laboratory experiments on interstellar dust analogues have shown that H_2 formation on dust grain surfaces is efficient in a range of grain temperatures below 20 K. These results indicate that surface processes may account for the…

Astrophysics · Physics 2009-11-13 Hagai B. Perets , Ofer Biham

We develop an unconditionally stable numerical method for solving the coupling between two fluids (frictional forces/heatings, ionization, and recombination), and investigate the dynamical condensation process of thermally unstable gas that…

Astrophysics · Physics 2010-12-20 Tsuyoshi Inoue , Shu-ichiro Inutsuka

We present observations of the H91$\alpha$ recombination line emission towards a sample of nine HII regions associated with 6.7-GHz methanol masers, and report arcsecond-scale emission around compact cores. We derive physical parameters for…

Astrophysics · Physics 2009-11-11 Stanislav Shabala , Simon Ellingsen , Stan Kurtz , Larry Forbes

I review recent observations of molecular gas in the halo of the Milky Way and in the Magellanic Clouds. Far-ultraviolet absorption line studies of molecular hydrogen (H_2) with ORFEUS and FUSE have unveiled the presence of a diffuse…

Astrophysics · Physics 2007-05-23 Philipp Richter

Ultraviolet lines of molecular hydrogen have been observed in solar spectra for almost four decades, but the behavior of the molecular spectrum and its implications for solar atmospheric structure are not fully understood. Data from the…

Solar and Stellar Astrophysics · Physics 2018-04-04 Sarah A. Jaeggli , Philip G. Judge , Adrian N. Daw

Three molecular clouds have been mapped in the nearby metal-poor dwarf irregular galaxy NGC 6822 using the Owens Valley Millimeter-Wave Interferometer. Based on upper limits to the virial masses of the clouds, the CO-to-H2 conversion factor…

Astrophysics · Physics 2009-10-22 C. D. Wilson

A sample of 66 galaxies from the catalog of Bettoni et al. (CISM) with anomalously high molecular-to-atomic hydrogen mass ratios (M_{mol}/M_{HI}>2) is considered. The sample galaxies do not differ systematically from other galaxies in the…

Astrophysics · Physics 2009-11-11 A. V. Kasparova , A. V. Zasov

We use passive gas tracer particles in an Arepo simulation of a dwarf spiral galaxy to relate the Lagrangian evolution of star-forming gas parcels and their H2 molecules to the evolution of their host giant molecular clouds. We find that…

Astrophysics of Galaxies · Physics 2023-01-26 Sarah M. R. Jeffreson , Vadim A. Semenov , Mark R. Krumholz

The influence of turbulent mixing on the chemistry of the interstellar medium has so far received little attention. Previous studies of this effect have suggested that it might play an important role in mixing the various phases of the…

Astrophysics of Galaxies · Physics 2015-05-27 T. A. Bell , K. Willacy , T. G. Phillips , M. Allen , D. C. Lis

Recent observations have revealed significant variations in the abundances of gas- and ice-phase molecules in galaxies with different luminosities and types. In order to discuss the physical origins of these variations, we incorporate gas-…

Astrophysics of Galaxies · Physics 2025-12-16 K. Bekki , K. Furuya , T. Shimonishi

Physical conditions in dense and cold regions of interstellar clouds favour the formation of ice mantles on the surfaces of interstellar grains. It is predicted that most of the gaseous species heavier than H2 or He will adsorb onto the…

Astrophysics of Galaxies · Physics 2015-06-12 Oscar Morata , Tatsuhiko I. Hasegawa

Turbulent diffuse molecular clouds can exhibit complicated morphologies caused by the interactions among radiation, chemistry, fluids, and fields. We performed full 3D simulations for turbulent diffuse molecular interstellar media,…

Astrophysics of Galaxies · Physics 2024-07-17 Nannan Yue , Lile Wang , Thomas Bisbas , Donghui Quan , Di Li

We simulate fragmentation and gravitational collapse of cold, magnetized molecular clouds. We explore the nonlinear development of an instability mediated by ambipolar diffusion, in which the collapse rate is intermediate to fast…

Astrophysics · Physics 2009-10-31 R. Indebetouw , E. G. Zweibel

We suggest that Bipolar H{\sc ii} Regions may be the aftermath of collisions between clouds. Such a collision will produce a shock-compressed layer, and a star cluster can then condense out of the dense gas near the centre of the layer. If…

Astrophysics of Galaxies · Physics 2018-11-19 Anthony Whitworth , Oliver Lomax , Scott Balfour , Pierre Mège , Annie Zavagno , Lise Deharveng

The G2 object has recently passed its pericenter passage in our Galactic Center. While the $Br_\gamma$ emission shows clear signs of tidal interaction, the change in the observed luminosity is only of about a factor of 2, in contention with…

The intermittent dissipation of interstellar turbulence is an important energy source in the diffuse ISM. Though on average smaller than the heating rates due to cosmic rays and the photoelectric effect on dust grains, the turbulent cascade…

Astrophysics of Galaxies · Physics 2015-09-11 Andrew Myers , Christopher McKee , Pak Shing Li