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Related papers: Chemical Differentiation toward the Pipe Nebula St…

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We present observations of the four hyperfine structure components of the OH 18 cm transition (1612, 1665, 1667 and 1720 MHz) toward a filamentary dark cloud, the Pipe nebula, with the Green Bank Telescope. A statistical equilibrium…

Astrophysics of Galaxies · Physics 2020-12-09 Yuji Ebisawa , Nami Sakai , Karl M. Menten , Yoko Oya , Satoshi Yamamoto

G10.21-0.31 is a 70 $\mu$m-dark high-mass starless core ($M>300$ $\mathrm{M_{\odot}}$ within $r<0.15$ pc) identified in $Spitzer$, $Herschel$, and APEX continuum surveys, and is believed to harbor the initial stages of high-mass star…

Astrophysics of Galaxies · Physics 2023-03-15 Wenyu Jiao , Ke Wang , Thushara G. S. Pillai , Tapas Baug , Siju Zhang , Fengwei Xu

We aim to characterize the physical and chemical properties of fragmented cores during the earliest evolutionary stages in the very young star-forming regions ISOSS J22478+6357 and ISOSS J23053+5953. NOEMA 1.3 mm data are used in…

We present a new catalogue of 406 dense cores optically selected by using the STScI Digitized Sky Survey (DSS). In this catalogue 306 cores have neither an Embedded YSO (EYSO) nor a Pre-Main-Sequence (PMS) star, 94 cores have EYSOs (1 core…

Astrophysics · Physics 2011-05-05 Chang Won Lee , Philip C. Myers

Class 0 objects, which are thought to be the youngest protostars, are identified in terms of NIR or radio emission and/or the presence of molecular outflows. We present combined hydrodynamic and radiative transfer simulations of the…

Astrophysics · Physics 2009-11-11 D. Stamatellos , A. P. Whitworth , S. P. Goodwin

(Abridged) We aim to determine the degrees of CO depletion, deuterium fractionation, and ionisation in a sample of seven massive clumps associated with IRDCs. The APEX telescope was used to observe the C17O(2-1), H13CO+(3-2), DCO+(3-2),…

Astrophysics of Galaxies · Physics 2015-05-30 Oskari Miettinen , Martin Hennemann , Hendrik Linz

Chemical reactions in starless molecular clouds are heavily dependent on interactions between gas phase material and solid phase dust and ices. We have observed the abundance and distribution of molecular gases in the cold, starless core DC…

Astrophysics of Galaxies · Physics 2013-01-15 E. E. Hardegree-Ullman , J. Harju , M. Juvela , O. Sipila , D. C. B. Whittet , S. Hotzel

Broadband spectroscopic observations with high sensitivity provide an unbiased way to detect emissions of molecules in space. We present deep observations from ~ 105.8 GHz to 113.6 GHz toward 50 Galactic massive star-forming regions using…

Solar and Stellar Astrophysics · Physics 2024-12-16 Xuefang Xu , Junzhi Wang , Qian Gou , Juan Li , Donghui Quan , Di Li , Fei Li , Chunguo Duan , Juncheng Lei

Although the deuterium fraction is known to be a powerful evolutionary tracer, its variation within individual molecular cloud cores is still poorly understood. The northern $\int$-shaped filament and 20 individual starless cores in the…

Herschel/HIFI observations toward the compact HII region W51 has revealed the presence of a cold dense core along its line of sight in a high-velocity stream located just in front of W51. This detection has been made possible through…

Astrophysics of Galaxies · Physics 2016-12-21 C. Vastel , B. Mookerjea , J. Pety , M. Gérin

We have carried out mid-infrared spectroscopy of seven Galactic proto-planetary nebulae (PPNs) using the Spitzer Space Telescope. They were observed from 10-36 microns at relatively high spectral resolution, R~600. The sample was chosen…

Solar and Stellar Astrophysics · Physics 2011-02-11 Bruce J. Hrivnak , Kevin Volk , Sun Kwok

Determining the level of chemical complexity within dense starless and gravitationally bound prestellar cores is crucial for constructing chemical models, which subsequently constrain the initial chemical conditions of star formation. We…

Astrophysics of Galaxies · Physics 2021-04-28 Samantha Scibelli , Yancy Shirley , Anton Vasyunin , Ralf Launhardt

We have mapped six molecular cloud cores in the Orion A giant molecular cloud (GMC), whose kinetic temperatures range from 10 to 30 K, in CCS and N2H+ with Nobeyama 45 m radio telescope to study their chemical characteristics. We identified…

Since the start of ALMA observatory operation, new and important chemistry of infrared cold core was revealed. Molecular transitions at millimeter range are being used to identify and to characterize these sources. We have investigated the…

We present a 3-mm and 1.3-cm spectral line survey conducted with the Mopra 22-m and Parkes 64-m radio telescopes of a sample of 40 cold dust cores, previously observed with BLAST, including both starless and proto-stellar sources. 20…

We have performed a dense core survey toward the Infrared Dark Cloud G14.225-0.506 at 3 mm continuum emission with the Atacama Large Millimeter/Submillimeter Array (ALMA). This survey covers the two hub-filament systems with an angular…

The present study aims to characterise the physical and chemical properties of the protostellar core Orion B9-SMM3. The APEX telescope was used to perform a follow-up molecular line survey of SMM3. The following species were identified from…

Astrophysics of Galaxies · Physics 2016-07-13 Oskari Miettinen

Water is an important molecule in the chemical and thermal balance of dense molecular gas, but knowing its history through-out the various stages of the star formation is a fundamental problem. Its molecular deuteration provides us with a…

Solar and Stellar Astrophysics · Physics 2015-12-16 David Quénard , Vianney Taquet , Charlotte Vastel , Paola Caselli , Cecilia Ceccarelli

The detection of complex organic molecules (COMs) toward dense, collapsing prestellar cores has sparked interest in the fields of astrochemistry and astrobiology, yet the mechanisms for COM formation are still debated. It was originally…

Astrophysics of Galaxies · Physics 2023-04-05 Samantha Scibelli , Yancy Shirley

(Abridged) Complex organic molecules (COMs) are considered essential precursors to prebiotic species. While COMs were once expected to be efficiently destroyed under UV-irradiated conditions, detections in photodissociation regions (PDRs)…

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