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Related papers: Dense Molecular Cores Being Externally Heated

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In order to search for intensity fluctuations on the HCN(1--0) and HCO$^+$(1--0) line profiles which could arise due to possible small-scale inhomogeneous structure long-time observations of the S140 and S199 high-mass star-forming cores…

Astrophysics of Galaxies · Physics 2018-08-15 Lev Pirogov

We present dust column densities and dust temperatures for $\sim3000$ young high-mass molecular clumps from the Millimetre Astronomy Legacy Team 90 GHz (MALT90) survey, derived from adjusting single temperature dust emission models to the…

Solar and Stellar Astrophysics · Physics 2015-12-24 Andrés E. Guzmán , Patricio Sanhueza , Yanett Contreras , Howard A. Smith , James M. Jackson , Sadia Hoq , Jill M. Rathborne

The densest infrared dark clouds (IRDCs) may represent the earliest observable stage of high-mass star formation. These clouds are very cold, hence they emit mainly at far-infrared and sub-mm wavelengths. For the first time, Herschel has…

The recent analysis of observations taken with the EIS instrument on Hinode suggests that well constrained measurements of the temperature distribution in solar active regions can finally be made. Such measurements are critical for…

Solar and Stellar Astrophysics · Physics 2015-06-04 Harry P. Warren , Amy R. Winebarger , David H. Brooks

We study non-thermal emissions from cool cores in galaxy clusters. We adopted a recent model, in which cosmic-rays (CRs) prevail in the cores and stably heat them through CR streaming. The non-thermal emissions come from the interaction…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Yutaka Fujita , Yutaka Ohira

We have used archival far-ultraviolet spectra from observations made by HST/STIS and FUSE to determine the column densities and rotational excitation temperatures for CO and H2, respectively, along the lines of sight to 23 Galactic O and B…

Astrophysics · Physics 2009-01-19 Eric B. Burgh , Kevin France , Stephan R. McCandliss

Neutron stars (NSs) provide a unique laboratory to probe dark matter (DM) through its gravitational imprint on stellar evolution. We use a two-fluid framework with non-annihilating, asymmetric DM, both fermionic and bosonic, that interacts…

High Energy Astrophysical Phenomena · Physics 2026-04-16 Adamu Issifu , Prashant Thakur , Davood Rafiei Karkevandi , Franciele M. da Silva , Débora P. Menezes , Y. Lim , Tobias Frederico

Pre-stellar cores within molecular clouds provide the very initial conditions in which stars are formed. We use the IRAM 30m telescope and the PdBI to study the chemical and physical properties of the starless core FeSt 1-457 (Core 109), in…

The sulfur content in dense molecular regions of the interstellar medium is highly depleted in comparison to diffuse clouds. The reason of this phenomenon is unclear, thus it is necessary to carry out observational studies of sulfur-bearing…

Astrophysics of Galaxies · Physics 2024-12-11 N. C. Martinez , S. Paron , M. E. Ortega , A. Petriella , A. Álamo , M. Brook , C. Carballo , T. Heberling

We present the results of an extensive mapping survey of 53 `starless' cores in the optically thick line of CS 2-1 and the optically thin lines of N2H+ 1-0 and C18O 1-0. The purpose of this survey was to search for signatures of extended…

Astrophysics · Physics 2009-11-06 Chang Won Lee , Philip C. Myers , Mario Tafalla

To understand the chemistry of sulphur (S) in the interstellar medium, models need to be tested by observations of S-bearing molecules in different physical conditions. We analyse observations obtained with the IRAM 30m telescope towards 15…

Astrophysics of Galaxies · Physics 2023-10-17 F. Fontani , E. Roueff , L. Colzi , P. Caselli

To constrain models of high-mass star formation, the Herschel/HOBYS KP aims at discovering massive dense cores (MDCs) able to host the high-mass analogs of low-mass prestellar cores, which have been searched for over the past decade. We…

The extinction curve of interstellar dust in the dense molecular cloud cores is crucial for understanding dust properties, particularly size distribution and composition. We investigate the infrared extinction law in four nearby isolated…

Astrophysics of Galaxies · Physics 2024-11-04 Jun Li , Bingqiu Chen , Biwei Jiang , He Zhao , Botao Jiang , Xi Chen

Cold ($\sim$10 K) and dense ($\sim$10$^{5}$ cm$^{-3}$) cores of gas and dust within molecular clouds, known as starless and dynamically evolved prestellar cores, are the birthplaces of low-mass ($M$ $\leq$ few M$_\odot$) stars. As…

Astrophysics of Galaxies · Physics 2024-08-22 Samantha Scibelli , Yancy Shirley , Andrés Megías , Izaskun Jiménez-Serra

The physical, chemical and kinetic characteristics of 12 northern infrared dark clouds (IRDCs) are systematic studied using the $\rm ^{13}CO $ (1-0) and $\rm C^{18}O$ (1-0) lines, observed with the PMO 13.7 m radio telescope, the 1.1 mm…

Astrophysics of Galaxies · Physics 2015-06-22 Xiao-Lan Liu , Jun-Jie Wang , Jin-Long Xu

The dust emission spectrum and the brightness profile of passively heated condensed cores is analyzed in relation to their astrophysical environment. The cores are modeled as critically stable self-gravitating spheres embedded at the center…

Astrophysics of Galaxies · Physics 2010-11-16 Joerg Fischera

We are addressing the sites of isolated low mass star formation in the solar neighbourhood, i.e. small cloud cores within one kiloparsec. We aim at determining the physical parameters of the cores, i.e., temperature, volume density, column…

Astrophysics of Galaxies · Physics 2017-03-21 Bengt Larsson , René Liseau

The Polaris Flare cloud region contains a great deal of extended emission. It is at high declination and high Galactic latitude. It was previously seen strongly in IRAS Cirrus emission at 100 microns. We have detected it with both PACS and…

During star formation, the dense gas undergoes significant chemical evolution leading to the emergence of a rich variety of molecules associated with hot cores and hot corinos. The physical and chemical conditions are poorly constrained;…

Astrophysics of Galaxies · Physics 2022-06-08 L. Bouscasse , T. Csengeri , A. Belloche , F. Wyrowski , S. Bontemps , R. Güsten , K. M. Menten

First protostellar cores are young stellar objects in the earliest evolutionary stage. They are hydrostatic objects formed soon after the central portions of star-forming cores become optically thick to dust emission. We consider their…

Astrophysics · Physics 2015-05-13 K. Omukai
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