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Related papers: Internal Motions in Starless Dense Cores

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We present a study of analytic models of starless cores whose line profiles have ``infall asymmetry,'' or blue-skewed shapes indicative of contracting motions. We compare the ability of two types of analytical radiative transfer models to…

Astrophysics · Physics 2009-11-10 Christopher H. De Vries , Philip C. Myers

The mass distributions of dense cores in star-forming regions are measured to have a shape similar to the initial mass function of stars. This has been generally interpreted to mean that the constituent cores will form individual stars or…

Astrophysics · Physics 2009-11-13 Jonathan J. Swift , Jonathan P. Williams

The results of spectral observations in the $\sim 84-92$ GHz frequency range of six objects in the southern sky containing dense cores and associated with regions of massive stars and star clusters formation are presented. The observations…

Astrophysics of Galaxies · Physics 2024-03-06 L. E. Pirogov , P. M. Zemlyanukha , E. M. Dombek , M. A. Voronkov

We propose an analytical model for the quasistatic evolution of starless cores confined by a constant external pressure, assuming that cores are isothermal and obey a spherically-symmetric density distribution. We model core evolution for…

Astrophysics of Galaxies · Physics 2016-04-20 Kate Pattle

The mass distribution of dense cores is a potential key to understand the process of star formation. Applying dendrogram analysis to the CARMA-NRO Orion C$^{18}$O ($J$=1--0) data, we identify 2342 dense cores, about 22 \% of which have…

In this paper, we present the first results of a survey of 220 starless cores selected primarily by their optical obscuration (Lee & Myers 1999) and observed in CS (2-1), N$_2$H$^+$ (1-0), and C$^{18}$O (1-0) using the NEROC Haystack 37-m…

Astrophysics · Physics 2009-10-31 Chang Won Lee , Philip C. Myers , Mario Tafalla

In the standard picture of isolated star formation, dense ``starless'' cores are formed out of magnetic molecular clouds due to ambipolar diffusion. Under the simplest spherical geometry, I demonstrate that ``starless'' cores formed this…

Astrophysics · Physics 2009-10-31 Zhi-Yun Li

High-mass stars have an enormous influence on the evolution of the interstellar medium in galaxies, so it is important that we understand how they form. We examine the central clumps within a sample of seven infrared-dark clouds (IRDCs)…

We present the dynamical properties of 294 cores embedded in twelve IRDCs observed as part of the ASHES Survey. Protostellar cores have higher gas masses, surface densities, column densities, and volume densities than prestellar cores,…

We study the density structure of candidate contracting starless core L694-2 using 1.3 mm dust continuum observations from the IRAM Plateau de Bure Interferometer and the Berkeley-Illinois-Maryland Array, probing spatial scales from…

Astrophysics · Physics 2009-11-10 Daniel W. A. Harvey , David J. Wilner , Philip C. Myers , Mario Tafalla

We study the kinematics of the dense gas of starless and protostellar cores traced by the N2D+(2-1), N2H+(1-0), DCO+(2-1), and H13CO+(1-0) transitions along the L1495 filament and the kinematic links between the cores and the surrounding…

Astrophysics of Galaxies · Physics 2018-09-12 A. Punanova , P. Caselli , J. E. Pineda , A. Pon , M. Tafalla , A. Hacar , L. Bizzocchi

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

Motivated by recent observational searches of sub-structure in starless molecular cloud cores, we investigate the evolution of density perturbations on scales smaller than the Jeans length embedded in contracting isothermal clouds, adopting…

Solar and Stellar Astrophysics · Physics 2017-12-20 C. Toci , D. Galli , A. Verdini , L. Del Zanna , S. Landi

Studies of the structure and kinematics of cores associated with the regions of massive star and star cluster formation are necessary for constructing scenario for the evolution of these objects. We analyzed spectral maps of the massive…

Astrophysics of Galaxies · Physics 2025-03-13 L. E. Pirogov , P. M. Zemlyanukha , E. M. Dombek

The research of infall motion is a common means to study molecular cloud dynamics and the early process of star formation. Many works had been done in-depth research on infall. We searched the literature related to infall study of molecular…

Astrophysics of Galaxies · Physics 2022-09-14 Shuling Yu , Zhibo Jiang , Yang Yang , Zhiwei Chen , Haoran Feng

The evolution of star-forming core analogues undergoing inside-out collapse is studied with a multi-point chemodynamical model which self-consistently computes the abundance distribution of chemical species in the core. For several collapse…

Astrophysics · Physics 2008-07-27 Y. G. Tsamis , J. M. C. Rawlings , J. A. Yates , S. Viti

Observations are revealing the ubiquity of filamentary structures in molecular clouds. As cores are often embedded in filaments, it is important to understand how line profiles from such systems differ from those of isolated cores. We…

Astrophysics of Galaxies · Physics 2015-06-04 Rowan J. Smith , Rahul Shetty , Amelia M. Stutz , Ralf S. Klessen

If the split, asymmetric molecular spectral line profiles that are seen in many starless cores are interpreted as indicative of global collapse or expansion of the core then one possible implication is that most starless cores have short…

Astrophysics · Physics 2009-11-11 Eric Keto , Avery Broderick , Charles J. Lada , Ramesh Narayan

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

We revisit the interpretation of blue-excess molecular lines from dense collapsing cores, considering recent numerical results that suggest prestellar core collapse occurs from the outside-in, and not inside-out. We thus create synthetic…

Astrophysics of Galaxies · Physics 2022-01-28 Robert M. Loughnane , Enrique Vázquez-Semadeni , Raúl Naranjo-Romero