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Related papers: The Dynamical State fo the Starless Dense Core FeS…

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We discuss the interstellar absorption from many atomic and molecular species seen in high-resolution $HST$/STIS UV and high-S/N optical spectra of the moderately reddened B3-5~V star HD~62542. This remarkable sight line exhibits both very…

Astrophysics of Galaxies · Physics 2020-07-08 Daniel E. Welty , Paule Sonnentrucker , Theodore P. Snow , Donald G. York

We test the hypothesis that the starless cores may be gravitationally bound clouds supported largely by thermal pressure by comparing observed molecular line spectra to theoretical spectra produced by a simulation that includes…

Astrophysics · Physics 2009-11-13 Eric Keto , George Field

Seven isolated, nearby low-mass starless molecular cloud cores have been observed as part of the Herschel key program Earliest Phases of Star formation (EPoS). By applying a ray-tracing technique to the obtained continuum emission and…

New molecular line observations of the Bok globule Barnard 68 in HCO+ irrefutably confirm the complex pattern of red and blue asymmetric line profiles seen across the face of the cloud in previous observations of CS. The new observations…

Astrophysics · Physics 2009-11-11 M. P. Redman , E. Keto , J. M. C. Rawlings

N2H+ observations of molecular cloud cores in Taurus with the Nobeyama 45 m radio telescope are reported. We compare ``cores with young stars'' with ``cores without young stars''. The differences in core radius, linewidth, and core mass are…

Astrophysics · Physics 2009-11-10 K. Tatematsu , T. Umemoto , R. Kandori , Y. Sekimoto

We investigate star formation at very early evolutionary phases in five massive clouds in the inner 500 pc of the Galaxy, the Central Molecular Zone. Using interferometer observations of H$_2$O masers and ultra-compact H II regions, we find…

We study the kinematic properties of dense gas surrounding massive protostars recognized by Bontemps et a. (2010) in a sample of five Massive Dense Cores in Cygnus-X. We investigate whether turbulent support plays a major role in…

Astrophysics of Galaxies · Physics 2015-05-19 T. Csengeri , S. Bontemps , N. Schneider , F. Motte , S. Dib

We present molecular-line observations of 94 dark cloud cores identified in the Pipe nebula through near-IR extinction mapping. Using the Arizona Radio Observatory 12m telescope, we obtained spectra of these cores in the J=1-0 transition of…

Astrophysics · Physics 2009-11-13 August A. Muench , Charles J. Lada , Jill M. Rathborne , João F. Alves , M. Lombardi

The $l=-1.2^{\circ}$ region in the Galactic center has a high CO $J$=3-2/$J$=1-0 intensity ratio and extremely broad velocity width. This paper reports the detection of five expanding shells in the $l=-1.2^{\circ}$ region based on the CO…

Astrophysics of Galaxies · Physics 2018-04-11 Shiho Tsujimoto , Tomoharu Oka , Shunya Takekawa , Masaya Yamada , Sekito Tokuyama , Yuhei Iwata , Justin A. Roll

In a previous paper we demonstrated that non-radial hydrodynamic oscillations of a thermally-supported (Bonnor-Ebert) sphere embedded in a low-density, high-temperature medium persist for many periods. The predicted column density…

Astrophysics · Physics 2008-04-14 Avery E. Broderick , Ramesh Narayan , Eric Keto , Charles J. Lada

We present the results of N2H+(1-0) observations of 35 dense molecular cloud cores from the northern and southern hemispheres where massive stars and star clusters are formed. Line emission has been detected in 33 sources, for 28 sources…

Astrophysics · Physics 2009-11-07 L. Pirogov , I. Zinchenko , P. Caselli , L. E. B. Johansson , P. C. Myers

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

Observational data for the hourglass-like magnetic field toward the starless dense core FeSt 1-457 were compared with a flux freezing magnetic field model (Myers et al. 2018). Fitting of the observed plane-of-sky magnetic field using the…

We have mapped the starless core TMC-1C in a variety of molecular lines with the IRAM 30m telescope. High density tracers show clear signs of self-absorption and sub-sonic infall asymmetries are present in N2H+ (1-0) and DCO+ (2-1) lines.…

Astrophysics · Physics 2009-11-13 S. Schnee , P. Caselli , A. Goodman , H. G. Arce , J. Ballesteros-Paredes , K. Kuchibhotla

The relation between ices in the envelopes and disks surrounding YSOs and those in the quiescent interstellar medium is investigated. For a sample of 31 stars behind isolated dense cores, ground-based and Spitzer spectra and photometry in…

A recent high angular resolution extinction map toward the most opaque molecular globule, Globule 2, in the Coalsack Nebula revealed that it contains a strong central ring of dust column density. This ring represents a region of high…

Astrophysics · Physics 2011-02-11 J. M. Rathborne , C. J. Lada , W. Walsh , M. Saul , H. M. Butner

Dense gas in molecular clouds is an important signature of ongoing and future star formation. We identify and track dense cores in the STARFORGE simulations, following the core evolution from birth through dispersal by stellar feedback for…

Astrophysics of Galaxies · Physics 2025-02-24 Stella S. R. Offner , Josh Taylor , Michael Y. Grudic

We present a spectroscopic study of the ``Disco Ball'' (SMDG0038365-064207), a rotationally-supported, red-sequence, ultra-diffuse galaxy (UDG) with a nuclear star cluster (NSC), multiple stellar clusters, and active star-forming regions…

Astrophysics of Galaxies · Physics 2025-08-15 Donghyeon J. Khim , Dennis Zaritsky , Loraine Sandoval Ascencio , M. C. Cooper , Richard Donnerstein

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

Spectral observations of molecular line profiles reveal the so-called `blue profiles' for double-peaked molecular lines with stronger blue and weaker red peaks as notable features for star-forming cloud core collapses under the…

Astrophysics of Galaxies · Physics 2015-05-20 Yu-Qing Lou , Yang Gao