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Related papers: A High-Resolution Study of the CO-H2 Conversion Fa…

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We present $^{12}$CO, $^{13}$CO, and C$^{18}$O data as the next major release for the CHaMP project, an unbiased sample of Galactic molecular clouds in $l$ = 280$^{\circ}$-300$^{\circ}$. From a radiative transfer analysis, we…

Astrophysics of Galaxies · Physics 2018-10-17 Peter J. Barnes , Audra K. Hernandez , Erik Muller , Rebecca L. Pitts

We present the first high angular resolution study of giant molecular clouds (GMCs) in the nearby spiral galaxy NGC 300, based on observations from the Submillimeter Array (SMA). We target eleven 500 pc-sized regions of active star…

Astrophysics of Galaxies · Physics 2016-04-28 Christopher Faesi , Charles Lada , Jan Forbrich

To understand the impact of low metallicities on giant molecular cloud (GMC) structure, we compare far infrared dust emission, CO emission, and dynamics in the star-forming complex N83 in the Wing of the Small Magellanic Cloud. Dust…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-12 A. K. Leroy , A. Bolatto , C. Bot , C. W. Engelbracht , K. Gordon , F. P. Israel , M. Rubio , K. Sandstrom , S. Stanimirović

Recent observations suggest that Tycho's supernova remnant (SNR; SN 1572) is expanding into a cavity wall of molecular clouds (MCs), which decelerate the SNR and influence its multi-wavelength morphology. To constrain the physical…

Astrophysics of Galaxies · Physics 2025-12-12 Sendi Bo , Yu Huang , Ping Zhou , Tian-Yu Tu , Samar Safi-Harb , Zhi-Yu Zhang , Yang Chen , Hidetoshi Sano

CO is the most widely used observational tracer of molecular gas. The observable CO luminosity is translated to H_2 mass via a conversion factor, X_CO, which is a source of uncertainty and bias. Despite variations in X_CO, the…

Astrophysics of Galaxies · Physics 2020-11-18 Munan Gong , Eve C. Ostriker , Chang-Goo Kim , Jeong-Gyu Kim

We present observations of the CO isotopologues ($^{12}$CO, $^{13}$CO, and C$^{18}$O) toward the Galactic region with $169\arcdeg.75 \leqslant l \leqslant 174\arcdeg.75$ and $-0\arcdeg.75 \leqslant b \leqslant 0\arcdeg.5$, using the Purple…

Astrophysics of Galaxies · Physics 2019-08-22 Fang Xiong , Xuepeng Chen , Qizhou Zhang , Ji Yang , Min Fang , Miaomiao Zhang , Weihua Guo , Li Sun

We study the properties of giant molecular clouds (GMCs) from a smoothed particle hydrodynamics simulation of a portion of a spiral galaxy, modelled at high resolution, with robust representations of the physics of the interstellar medium.…

Astrophysics of Galaxies · Physics 2016-03-31 A. Duarte-Cabral , C. L. Dobbs

The CO-H2 conversion factor in galaxies is typically described as bimodal: one value for discs and quiescent regions, and another (lower) value for mergers and starbursts. In this proceeding, I will describe both empirical observational…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-07 Desika Narayanan

Observations of the dust emission using millimetre/submillimetre bolometer arrays can be contaminated by molecular line flux, such as flux from 12CO. As the brightest molecular line in the submillimetre, it is important to quantify the…

Astrophysics of Galaxies · Physics 2015-06-04 E. Drabek , J. Hatchell , P. Friberg , J. Richer , S. Graves , J. V. Buckle , D. Nutter , D. Johnstone , J. Di Francesco

Estimating molecular abundances ratios from the direct measurement of the emission of the molecules towards a variety of interstellar environments is indeed very useful to advance in our understanding of the chemical evolution of the…

Astrophysics of Galaxies · Physics 2018-09-12 S. Paron , M. B. Areal , M. E. Ortega

We observed 51 positions in the OH 1667 MHz main line transitions in the translucent, high latitude cloud MBM40. We detected OH emission in 8 out of 8 positions in the molecular core of the cloud and 24 out of 43 in the surrounding, lower…

Astrophysics of Galaxies · Physics 2015-06-04 David L. Cotten , Loris Magnani , Elizabeth A. Wennerstrom , Kevin A. Douglas , Joseph S. Onello

Infrared-dark high-mass clumps are among the most promising objects to study the initial conditions of the formation process of high-mass stars and rich stellar clusters. In this work, we have observed the (3-2) rotational transition of…

Astrophysics of Galaxies · Physics 2015-06-04 F. Fontani , A. Giannetti , M. T. Beltran , R. Dodson , M. Rioja , J. Brand , P. Caselli , R. Cesaroni

The dense cloud associated with W40, one of the nearby H II regions, has been studied in millimeter-wave molecular lines and in 1.2 mm continuum. Besides, 1280 MHz and 610 MHz interferometric observations have been done. The cloud has…

Astrophysics of Galaxies · Physics 2015-06-17 L. Pirogov , D. K. Ojha , M. Thomasson , Y. -F. Wu , I. Zinchenko

We analyze the line ratio of the $^{13}$CO (2-1) to $^{12}$CO (2-1) rotational transitions observed from new ALMA observations of 100 Giant Molecular Clouds (GMCs) that span the Large Magellanic Cloud. We measure a median line ratio of…

Astrophysics of Galaxies · Physics 2026-05-19 Dia Kalra , Erik Rosolowsky , Adam Leroy , Remy Indebetouw

We have constructed three-dimensional models for the equilibrium abundance of molecular hydrogen within diffuse interstellar clouds of arbitrary geometry that are illuminated by ultraviolet radiation. The position-dependent photo-…

Astrophysics · Physics 2009-10-30 Marco Spaans , David A. Neufeld

We have mapped the dark cloud L183 in the far-infrared at 100um and 200um with the ISOPHOT photometer aboard the ISO satellite. The observations make it possible for the first time to study the properties of the large dust grains in L183…

Astrophysics · Physics 2009-11-07 M. Juvela , K. Mattila , K. Lehtinen , D. Lemke , R. Laureijs , T. Prusti

We report the results of initial FUSE observations of molecular hydrogen (H2) in translucent clouds. These clouds have greater optical depth than any of the diffuse clouds previously observed for far-UV H2 absorption, and provide new…

We recently reported a population of protostellar candidates in the 20 km s$^{-1}$ cloud in the Central Molecular Zone of the Milky Way, traced by H$_2$O masers in gravitationally bound dense cores. In this paper, we report…

We have simultaneously observed $^{12}$CO, $^{13}$CO, and C$^{18}$O (J=1$-$0) rotational transitions in the centers of a sample of 58 nearby spiral galaxies using the 13.7-m millimeter-wave telescope of the Purple Mountain Observatory.…

Astrophysics of Galaxies · Physics 2015-06-03 Fa-Cheng Li , Yuan-Wei Wu , Ye Xu

CO and dust emission at millimeter wavelengths are independent tracers of cold interstellar matter, which have seldom been compared on the scale of GMCs in other galaxies. In this study, and for the first time in the Large Magellanic Cloud,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Cinthya N. Herrera , Monica Rubio , Alberto D. Bolatto , Francois Boulanger , Frank P. Israel , Fredrik T. Rantakyro