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We present new Plateau de Bure Interferometer observations of a region in the filamentary infrared-dark cloud (IRDC) G011.11-0.12 containing young, star-forming cores. In addition to the 3.2mm continuum emission from cold dust, we map this…

Astrophysics of Galaxies · Physics 2015-01-14 Sarah E. Ragan , Thomas Henning , Henrik Beuther , Hendrik Linz , Sarolta Zahorecz

Star formation in the central molecular zone (CMZ) is suppressed with respect to that of the Galactic disk, and this is likely related to its high turbulent environment. This turbulence impedes the potential detection of prestellar cores.…

Astrophysics of Galaxies · Physics 2024-09-02 L. Colzi , J. Martín-Pintado , S. Zeng , I. Jiménez-Serra , V. M. Rivilla , M. Sanz-Novo , S. Martín , Q. Zhang , X. Lu

Molecular line CN, CS and mm continuum observations of two intermediate- to high-mass star-forming regions - IRAS20293+3952 and IRAS19410+2336 - obtained with the Plateau de Bure Interferometer at high spatial resolution reveal interesting…

Astrophysics · Physics 2009-11-10 H. Beuther , P. Schilke , F. Wyrowski

We present newly processed archival Herschel images of molecular cloud MCLD 123.5+24.9 in the Polaris Flare. This cloud contains five starless cores. Using the spectral synthesis code Cloudy, we explore uncertainties in the derivation of…

Astrophysics of Galaxies · Physics 2015-08-10 Gururaj A. Wagle , Thomas H. Troland , Gary J. Ferland , Nicholas P. Abel

We have conducted a survey of the CCS $J_N = 3_2-2_1$ line toward 11 dark clouds and star-forming regions at 30 arcsec spatial resolution and 0.054 km/s velocity resolution. CCS was only detected in quiescent clouds, not in active…

Astrophysics · Physics 2009-10-31 Shih-Ping Lai , Richard M. Crutcher

We investigate, through a series of numerical calculations, the evolution of dense cores that are accreting external gas up to and beyond the point of star formation. Our model clouds are spherical, unmagnetized configurations with fixed…

Solar and Stellar Astrophysics · Physics 2015-06-16 Motahareh Mohammadpour , Steven W. Stahler

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…

Prestellar cores, the birthplace of Sun-like stars, form from the fragmentation of the filamentary structure that composes molecular clouds, from which they must inherit at least partially the kinematics. Furthermore, when they are on the…

Astrophysics of Galaxies · Physics 2022-12-28 E. Redaelli , A. Chacón-Tanarro , P. Caselli , M. Tafalla , J. E. Pineda , S. Spezzano , O. Sipilä

We present Submillimeter Array (SMA) observations of seven massive molecular clumps which are dark in the far-infrared for wavelengths up to 70 $\mu$m. Our 1.3 mm continuum images reveal 44 dense cores, with gas masses ranging from 1.4 to…

Astrophysics of Galaxies · Physics 2019-12-11 Shanghuo Li , Qizhou Zhang , Thushara Pillai , Ian W. Stephens , Junzhi Wang , Fei Li

We present high-angular resolution sub-millimeter continuum images and molecular line spectra obtained with the SMA toward two massive cores that lie within Infrared Dark Clouds; one actively star-forming (G034.43+00.24 MM1) and the other…

Astrophysics · Physics 2009-11-13 J. M. Rathborne , J. M. Jackson , Q. Zhang , R. Simon

In this paper we present the results of a high resolution (5") CARMA and SZA survey of the 3mm continuum emission from 11 of the brightest (at 1.1mm) starless cores in the Perseus molecular cloud. We detect 2 of the 11 cores, both of which…

Astrophysics of Galaxies · Physics 2015-05-19 Scott Schnee , Melissa Enoch , Doug Johnstone , Thomas Culverhouse , Erik Leitch , Daniel P. Marrone , Anneila Sargent

The first hydrostatic core, the first quasi-hydrostatic object formed during the star formation process, is still the observational missing link between the prestellar and protostellar phases, mainly due to its short lifetime. Although we…

The relative importance of primordial molecular cloud fragmentation versus large-scale accretion still remains to be assessed in the context of massive core/star formation. Studying the kinematics of the dense gas surrounding massive-star…

We present new interferometric $^{12}CO$(1-0) and single-dish CO(3-2) observations of the central parts of D478, a large (> 200 pc) dark dust cloud located in a quiescent region of the inner disk of M31 where single-dish CO(1-0) and CO(2-1)…

Astrophysics · Physics 2007-05-23 Laurent Loinard Ronald J. Allen

High-resolution spectroscopic observations (UV HST/STIS and optical) are used to characterize the physical state and velocity structure of the multiphase interstellar medium seen towards the nearby (170 pc) star HD102065, located behind the…

Astrophysics · Physics 2009-11-13 C. Nehme , C. Gry , F. Boulanger , J. Le Bourlot , G. Pineau des Forets , E. Falgarone

We present CS(3-2) and DCO+(2-1) observations of 94 starless cores and compare the results with previous CS(2-1) and N2H+(1-0) observations to study inward motions in starless cores. The velocity shifts of the CS(3-2) and (2-1) lines with…

Astrophysics · Physics 2009-11-10 Chang Won Lee , Philip C. Myers , Rene Plume

Chemical composition of the massive cores forming high-mass stars can put some constrains on the time scale of the massive star formation: sulphur chemistry is of specific interest due to its rapid evolution in warm gas and because the…

Solar and Stellar Astrophysics · Physics 2009-10-28 Fabrice Herpin , Matthieu Marseille , Valentine Wakelam , Sylvain Bontemps , D. C. Lis

We present high spatial resolution Submillimeter Array observations and supplementary single-dish photometry of the molecular gas and dust around IRAS 04158+2805, a young source with spectral type M5-M6 in the Taurus star-forming region. A…

Astrophysics · Physics 2009-11-13 Sean M. Andrews , Michael C. Liu , Jonathan P. Williams , K. N. Allers

We present a first attempt to construct an analytic model for a clumped gas and dust disk and apply it to the Galactic Centre. The clumps are described as isothermal spheres partially ionized by the external UV radiation field. The disk…

Astrophysics · Physics 2009-10-31 B. Vollmer , W. J. Duschl

We have studied the physical and chemical properties of a quiescent starless core L1521E with various molecular lines. It is found that there exists a compact dense core traced by the H^13CO^+, HN^13C, CCS, and HC_3N lines; their…

Astrophysics · Physics 2009-11-07 T. Hirota , T. Ito , S. Yamamoto