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Related papers: W49A North - Global or Local or No Collapse?

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We present an analysis of multi-wavelength observations from various datasets and Galactic plane surveys to study the star formation process in the W42 complex. A bipolar appearance of W42 complex is evident due to the ionizing feedback…

Astrophysics of Galaxies · Physics 2015-09-30 L. K. Dewangan , A. Luna , D. K. Ojha , B. G. Anandarao , K. K. Mallick , Y. D. Mayya

Observed molecular clouds often appear to have very low star formation efficiencies and lifetimes an order of magnitude longer than their free-fall times. Their support is attributed to the random supersonic motions observed in them. We…

Astrophysics · Physics 2010-10-28 Ralf S. Klessen , Fabian Heitsch , Mordecai-Mark Mac Low

The massive star-forming region G332.83-0.55 contains at least two levels of hub-filament structures. The hub-filament structures may form through the "gravitational focusing" process. High-resolution LAsMA and ALMA observations can…

Astrophysics of Galaxies · Physics 2024-03-22 J. W. Zhou , S. Dib , M. Juvela , P. Sanhueza , F. Wyrowski , T. Liu , K. M. Menten

To understand the formation of stars from clouds of molecular gas, one essentially needs to know two things: What gas collapses, and how long it takes to do so. We address these questions by embedding pseudo-Lagrangian tracer particles in…

Astrophysics of Galaxies · Physics 2022-10-12 David C. Collins , Dan K. Le , Luz L. Jimenez Vela

The process of atomic-to-molecular (HI-to-H$_2$) gas conversion is fundamental for molecular-cloud formation and star formation. 21 cm observations of the star-forming region W43 revealed extremely high HI column densities, of 120-180…

Astrophysics of Galaxies · Physics 2017-02-01 Shmuel Bialy , Simon Bihr , Henrik Beuther , Thomas Henning , Amiel Sternberg

We present 45"-47" angular resolution maps at 50" sampling of the 12CO and 13CO J=1-0 emission toward a 1.39 deg x 1.33 deg region in the W51 HII region complex. These data permit the spatial and kinematic separation of several spectral…

Astrophysics · Physics 2009-10-30 John M. Carpenter , D. B. Sanders

We present results from the first three-dimensional calculations ever to follow the collapse of a molecular cloud core (~ 10^{-18} g cm^{-3}) to stellar densities (> 0.01 g cm^{-3}). The calculations resolve structures over 7 orders of…

Astrophysics · Physics 2009-10-31 Matthew R. Bate

We perform global linear stability analysis and idealized numerical simulations in global thermal balance to understand the condensation of cold gas from hot/virial atmospheres (coronae), in particular the intracluster medium (ICM). We pay…

Astrophysics of Galaxies · Physics 2016-02-15 Prakriti Pal Choudhury , Prateek Sharma

Flows of granular media down a rough inclined plane demonstrate a number of nonlocal phenomena. We apply the recently proposed nonlocal granular fluidity model to this geometry and find that the model captures many of these effects.…

Soft Condensed Matter · Physics 2014-08-25 Ken Kamrin , David Henann

We present the first results on the diffuse transition clouds observed in [CII] line emission at 158 microns (1.9 THz) towards Galactic longitudes near 340deg (5 LOSs) and 20deg (11 LOSs) as part of the GOT C+ survey. Out of the total 146…

Astrophysics of Galaxies · Physics 2015-05-19 T. Velusamy , W. D. Langer , J. L. Pineda , P. F. Goldsmith , D. Li. , H. W. Yorke

Molecular clouds form from the atomic phase of the interstellar medium. However, characterizing the transition between the atomic and the molecular interstellar medium (ISM) is a difficult observational task. Here we address cloud formation…

Understanding of cloud microphysics and the evolution of cloud structures in sub-stellar atmospheres remains a key challenge in the JWST era. The abundance of new JWST data necessitates models that are suitable for coupling with large-scale…

Earth and Planetary Astrophysics · Physics 2025-03-19 Elspeth K. H. Lee , Kazumasa Ohno

Comparison is made between a number of independent computer programs for radiative transfer in molecular rotational lines. The test models are spherically symmetric circumstellar envelopes with a given density and temperature profile. The…

We present preliminary numerical evidence that the physical conditions in high-mass star forming regions can arise from global gravitational infall, with the velocity dispersions being caused primarily by infall motions rather than random…

Context. Observations suggest that exoplanets such as HD 189733b form clouds in their atmospheres which have a strong feedback onto their thermodynamical and chemical structure, and overall appearance. Aims. Inspired by mineral cloud…

Earth and Planetary Astrophysics · Physics 2021-06-04 E. K. H. Lee , Ch. Helling , I. Dobbs-Dixon , D. Juncher

We have carried out sub-mm 12CO(J=3-2) observations of 6 giant molecular clouds (GMCs) in the Large Magellanic Cloud (LMC) with the ASTE 10m sub-mm telescope at a spatial resolution of 5 pc and very high sensitivity. We have identified 32…

The study of prestellar cores is critical as they set the initial conditions in star formation and determine the final mass of the stellar object. To date, several hypotheses are describing their gravitational collapse. We perform detailed…

Solar and Stellar Astrophysics · Physics 2020-11-04 E. Koumpia , L. Evans , J. Di Francesco , F. F. S. van der Tak , R. D. Oudmaijer

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 massive and luminous star-forming region W49A is a well known Galactic candidate to probe the physical conditions and chemistry similar to those expected in external starburst galaxies. We aim to probe the physical and chemical…

Astrophysics of Galaxies · Physics 2015-05-20 Z. Nagy , F. F. S. van der Tak , G. A. Fuller , R. Plume

Gas infall motions play a crucial role in high-mass star formation and are characterized by observable signatures in the form of blue-shifted asymmetric spectral line profiles ("blue profiles"). However, the connection between blue profiles…

Astrophysics of Galaxies · Physics 2023-09-27 Fengwei Xu , Ke Wang , Yuxin He , Jingwen Wu , Lei Zhu , Diego Mardones