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Related papers: Rethinking a Mysterious Molecular Cloud

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We analyze the gamma-ray emission from 9 high latitude, translucent molecular clouds taken with the Fermi Large Area Telescope (LAT) between 250 MeV and 10 GeV. Observations of gamma-rays allow us to probe the density and spectrum of cosmic…

High Energy Astrophysical Phenomena · Physics 2015-05-27 R. D. Abrahams , T. A. D. Paglione

We develop a detailed chemical model for the starless cores of strongly magnetized molecular clouds, with the ambipolar diffusion-driven dynamic evolution of the clouds coupled to the chemistry through ion abundances. We concentrate on two…

Astrophysics · Physics 2009-11-07 Zhi-Yun Li , V. I. Shematovich , D. S. Wiebe , B. M. Shustov

We have obtained column density maps for an unbiased sample of 120 molecular clouds in the third quadrant of the Milky Way mid-plane (b$\le |5|^{\circ}$) within the galactic longitude range from 195$^{\circ}$ to 225$^{\circ}$, using the…

Astrophysics of Galaxies · Physics 2022-08-31 Yuehui Ma , Hongchi Wang , Miaomiao Zhang , Chen Wang , Shaobo Zhang , Yao Liu , Chong Li , Yuqing Zheng , Lixia Yuan , Ji Yang

We present maps of 4 galactic giant molecular clouds (GMCs) in the J=2-1 emission of both CO and $^{13}$CO. We use an LTE analysis to derive maps of the CO excitation temperature and column density and the distribution of total molecular…

Astrophysics of Galaxies · Physics 2022-09-13 John H. Bieging , Shuo Kong

Using archival, high-resolution far-ultraviolet HST/STIS spectra of 34 Galactic O and B stars, we measure CI column densities and compare them with measurements from the literature of CO and H_2 with regard to understanding the presence of…

Astrophysics of Galaxies · Physics 2014-11-20 Eric B. Burgh , Kevin France , Edward B. Jenkins

We report 350 and 230 GHz observations of molecular gas and dust in the starburst nucleus of NGC 253 at 20-40 pc (1"-2") resolution. The data contain CO(3-2), HCN(4-3), CO(2-1), 13CO(2-1), C18O(2-1), and continuum at 0.87 mm and 1.3 mm…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Kazushi Sakamoto , Rui-Qing Mao , Satoki Matsushita , Alison B. Peck , Tsuyoshi Sawada , Martina C. Wiedner

We present 12CO(1->0) observations of 45 giant molecular clouds in M33 made with the BIMA array. The observations have a linear resolution of 20 pc, sufficient to measure the sizes of most GMCs in the sample. We place upper limits on the…

Astrophysics · Physics 2009-11-10 Erik Rosolowsky , Greg Engargiola , Richard Plambeck , Leo Blitz

The purpose of the investigation is to probe the dust properties inside a molecular cloud, how particle grow and how the presence of ice coatings may change the overall shape of the extinction curve. Field stars can be used to probe the…

Astrophysics of Galaxies · Physics 2015-06-03 Sven Olofsson , Göran Olofsson

The factor relating CO emission to molecular hydrogen column density, XCO, is still subject to uncertainty, in particular at low metallicity. Here, to quantify XCO at two different spatial resolutions, we exploit a dust-based method…

Using the Planck far-infrared and Arecibo GALFA 21-cm line surveys, we identified a set of isolated interstellar clouds (approximately degree-sized on the sky and comprising 100 solar masses) and assessed the ratio of gas mass to dust mass.…

Astrophysics of Galaxies · Physics 2015-10-07 William T. Reach , Carl Heiles , Jean-Philippe Bernard

We report a new search for 12CO(1-0) emission in high-velocity clouds (HVCs) performed with the IRAM 30 m telescope. This search was motivated by the recent detection of cold dust emission in the HVCs of Complex C. Despite a spatial…

Astrophysics · Physics 2009-11-13 M. Dessauges-Zavadsky , F. Combes , D. Pfenniger

We have used archival FUSE data to complete a survey of interstellar HD in 41 lines of sight with a wide range of extinctions. This follow up to an earlier survey was made to further assess the utility of HD as a cosmological probe; to…

We aim to give a full description of the distribution and location of dense molecular clouds in the giant molecular cloud complex W43. It has previously been identified as one of the most massive star-forming regions in our Galaxy. To trace…

We report the first high-resolution (sub-arcminute) large-scale mapping $^{12}$CO and $^{13}$CO observations of the molecular clouds associated with the giant outer Galaxy HII region CTB~102 (KR 1). These observations were made using a…

Astrophysics of Galaxies · Physics 2019-05-08 Brandon Marshall , Sung-ju Kang , C. R. Kerton , Youngsik Kim , Minho Choi , Miju Kang

Emission line profiles of tracer molecule H$_2$CO 140 GHz transition from gravitational core collapsing clouds in the dynamic process of forming protostars are calculated, using a simple ray-tracing radiative transfer model. Three…

Solar and Stellar Astrophysics · Physics 2015-05-13 Yang Gao , Yu-Qing Lou , Kinwah Wu

Using Spitzer Space Telescope and Chandra X-ray Observatory data, we identify YSOs in the Rosette Molecular Cloud (RMC). By being able to select cluster members and classify them into YSO types, we are able to track the progression of star…

Solar and Stellar Astrophysics · Physics 2015-06-15 Jason E. Ybarra , Elizabeth A. Lada , Carlos G. Román-Zúñiga , Zoltan Balog , Junfeng Wang , Eric D. Feigelson

The nearby dwarf elliptical galaxy NGC 205 offers a unique opportunity for high resolution studies of the interstellar medium in an elliptical galaxy. This paper investigates the distribution of molecular gas, molecular line ratios, and the…

Astrophysics · Physics 2009-10-31 L. M. Young

Neither HI nor CO emission can reveal a significant quantity of so-called dark gas in the interstellar medium (ISM). It is considered that CO-dark molecular gas (DMG), the molecular gas with no or weak CO emission, dominates dark gas. We…

Astrophysics of Galaxies · Physics 2016-09-14 Ningyu Tang , Di Li , Carl Heiles , Shen Wang , Zhichen Pan , Jun-Jie Wang

Using the IRAM 30m telescope two molecular structures have been detected which cover very small areas, FWHM<1'. The clouds have velocities of v_lsr~5kms and linewidth of dv~0.8km/s; thus they belong most likely to the Milky Way. Applying…

Astrophysics · Physics 2009-11-07 Andreas Heithausen