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Related papers: How Starless Are Starless Cores?

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Motivated by a considerable scatter in the observationally inferred lifetimes of the embedded phase of star formation, we study the duration of the Class 0 and Class I phases in upper-mass brown dwarfs and low-mass stars using numerical…

Solar and Stellar Astrophysics · Physics 2015-05-18 Eduard Vorobyov

High resolution molecular line observations of CS, HCO+, C18O and N2H+ were obtained toward the starless globule FeSt 1-457 in order to investigate its kinematics and chemistry. The HCO+ and CS spectra show clear self-reversed and…

Astrophysics · Physics 2009-06-23 E. D. Aguti , C. J. Lada , E. A. Bergin , J. F. Alves , M. Birkinshaw

Dense low mass cores in nearby clouds like Taurus and Auriga are some of the simplest sites currently forming stars like our Sun. Because of their simplicity and proximity, dense cores offer the clearest view of the different phases of star…

Astrophysics · Physics 2017-03-08 Mario Tafalla

We describe a model for the thermal and dynamical equilibrium of starless cores that includes the radiative transfer of the gas and dust and simple CO chemistry. The model shows that the structure and behavior of the cores is significantly…

Astrophysics · Physics 2009-11-13 Eric Keto , Paola Caselli

We present results of our study on eight dense cores, previously classified as starless, using infrared (3-160 {\micron}) imaging observations with \textit{AKARI} telescope and molecular line (HCN and N$_2$H$^+$) mapping observations with…

Astrophysics of Galaxies · Physics 2016-06-22 Gwanjeong Kim , Chang Won Lee , Maheswar Gopinathan , Woong-Seob Jeong , Mi-Ryang Kim

We present first results from an unbiased 50 deg^2 submillimeter Galactic survey at 250, 350, and 500 micron from the 2006 flight of the Balloon-borne Large Aperture Submillimeter Telescope (BLAST). The map has resolution ranging from 36…

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

The aims of this study are to determine the properties and spatial distribution of dense cores in Ori B9, and to estimate their ages and dynamical timescales. The cloud was mapped in the 870 micron continuum with APEX/LABOCA, and selected…

Solar and Stellar Astrophysics · Physics 2009-11-17 O. Miettinen , J. Harju , L. K. Haikala , J. Kainulainen , L. E. B. Johansson

Molecular outflows provide an alternative method of identifying protostellar cores, complementary to recent mid-infrared studies. Continuing our studies of Perseus, we investigate whether all Spitzer-identified protostars, and particularly…

Astrophysics of Galaxies · Physics 2015-05-13 Jennifer Hatchell , Michael M. Dunham

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 discuss the lifetimes and evolution of dense cores formed as turbulent density fluctuations in magnetized, isothermal molecular clouds. We consider numerical simulations in which we measure the cores' magnetic criticality and Jeans…

Astrophysics · Physics 2007-05-23 E. Vazquez-Semadeni , J. Kim , M. Shadmehri , J. Ballesteros-Paredes

We present the detection of 89 low surface brightness (LSB), and thus low stellar density galaxy candidates in the Perseus cluster core, of the kind named "ultra-diffuse galaxies", with mean effective V-band surface brightnesses 24.8-27.1…

Compact substructure is expected to arise in a starless core as mass becomes concentrated in the central region likely to form a protostar. Additionally, multiple peaks may form if fragmentation occurs. We present ALMA Cycle 2 observations…

Identified as extinction features against the bright Galactic mid-infrared background, infrared dark clouds (IRDCs) are thought to harbor the very earliest stages of star and cluster formation. In order to better characterize the properties…

Solar and Stellar Astrophysics · Physics 2015-05-18 J. M. Rathborne , J. M. Jackson , E. T. Chambers , I. Stojimirovic , R. Simon , R. Shipman , W. Frieswijk

High-mass stars form within star clusters from dense, molecular regions, but is the process of cluster formation slow and hydrostatic or quick and dynamic? We link the physical properties of high-mass star-forming regions with their…

Astrophysics of Galaxies · Physics 2017-02-09 Cara Battersby , John Bally , Brian Svoboda

Spitzer Space Telescope observations of a point-like source, L1014-IRS, close to the dust peak of the low-mass dense core L1014 have questioned its starless nature. The presence of an object with colors expected for an embedded protostar…

(Abridged) We present an overview of the sample of high-mass star and cluster forming regions observed as part of the Earliest Phases of Star Formation (EPoS) Herschel Guaranteed Time Key Program. A sample of 45 infrared-dark clouds (IRDCs)…

Recently, the Spitzer Space Telescope discovered L1014-IRS, a mid-infrared source with protostellar colors, toward the heretofore "starless" core L1014. We present deep near-infrared observations that show a scattered light nebula extending…

Molecular inventories in starless cores are powerful tools for probing the physical and chemical structures at the earliest stages of star formation. Wide-band spectral scans are invaluable for obtaining a comprehensive view of the chemical…

We present an unbiased census of deeply embedded protostars in Perseus, Serpens, and Ophiuchus, assembled by combining large-scale 1.1 mm Bolocam continuum and Spitzer Legacy surveys. We identify protostellar candidates based on their…

Astrophysics · Physics 2014-11-18 Melissa L. Enoch , Neal J. Evans , Anneila I. Sargent , Jason Glenn