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Related papers: Internal Motions in Starless Dense Cores

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Low-mass dense cores represent the state of molecular gas associated with the earliest phases of low-mass star formation. Such cores are called "protostellar" or "starless," depending on whether they do or do not contain compact sources of…

Astrophysics · Physics 2007-05-23 J. Di Francesco , N. J. Evans , P. Caselli , P. C. Myers , Y. Shirley , A. Aikawa , M. Tafalla

In previous studies we identified two classes of starless cores, thermally subcritical and supercritical, distinguished by different dynamical behavior and internal structure. Here we study the evolution of the dynamically-unstable,…

Astrophysics of Galaxies · Physics 2015-05-13 Eric Keto , Paola Caselli

In this paper we present the results of a systematic investigation of an entire population of starless dust cores within a single molecular cloud. Analysis of extinction data shows the cores to be dense objects characterized by a narrow…

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

Five regions of massive star formation have been observed in various molecular lines in the frequency range $\sim 85-89$ GHz. The studied regions possess dense cores, which host young stellar objects. The physical parameters of the cores…

Astrophysics of Galaxies · Physics 2016-10-19 L. E. Pirogov , V. M. Shul'ga , I. I. Zinchenko , P. M. Zemlyanukha , O. N. Patoka , M. Thomasson

We aim at characterising dense cores in the clustered environments associated with massive star-forming regions. For this, we present an uniform analysis of VLA NH3(1,1) and (2,2) observations towards a sample of 15 massive star-forming…

We study the formation, evolution and collapse of dense cores by tracking structures in a magnetohydrodynamic simulation of a star-forming cloud. We identify cores using the dendrogram algorithm and utilize machine learning techniques,…

We investigate the physical properties of dense cores formed in turbulent, magnetized, parsec-scale clumps of molecular clouds, using three-dimensional numerical simulations that include protostellar outflow feedback. The dense cores are…

Solar and Stellar Astrophysics · Physics 2015-05-28 Fumitaka Nakamura , Zhi-Yun Li

Context. Low-mass star-forming cores differ from their surrounding molecular cloud in turbulence, shape, and density structure. Aims. We aim to understand how dense cores form out of the less dense cloud material by studying the connection…

Astrophysics of Galaxies · Physics 2015-05-28 A. Hacar , M. Tafalla

We review the properties of low mass dense molecular cloud cores, including starless, prestellar, and Class 0 protostellar cores, as derived from observations. In particular we discuss them in the context of the current debate surrounding…

Astrophysics · Physics 2007-05-23 D. Ward-Thompson , P. Andre , R. Crutcher , D. Johnstone , T. Onishi , C. Wilson

A sample of 1.3 mm continuum cores in the Dragon infrared dark cloud (also known as G28.37+0.07 or G28.34+0.06) is analyzed statistically. Based on their association with molecular outflows, the sample is divided into protostellar and…

Astrophysics of Galaxies · Physics 2021-05-26 Shuo Kong , Héctor G. Arce , Yancy Shirley , Colton Glasgow

In an attempt to understand the dynamics of collapsing starless cores, we have onducted a detailed investigation of the velocity fields of two collapsing cores, L694-2 and L1197, with high spatial resolution HCN J=1-0 maps and Monte Carlo…

Astrophysics · Physics 2011-02-11 Seok Ho Lee , Yong-Sun Park , Jungjoo Sohn , Chang Won Lee , Hyung Mok Lee

For a number of starless cores, self-absorbed molecular line and column density observations have implied the presence of large-amplitude oscillations. We examine the consequences of these oscillations on the evolution of the cores and the…

Solar and Stellar Astrophysics · Physics 2015-05-19 Avery E. Broderick , Eric Keto

Starless cores represent the initial stage of evolution toward (proto)star formation, and a subset of them, known as prestellar cores, with high density (~ 10^6 cm^-3 or higher) and being centrally concentrated are expected to be embryos of…

Mass functions of starless dense cores (CMFs) may arise from contraction and dispersal of core-forming filaments. In an illustrative model, a filament contracts radially by self-gravity, increasing the mass of its cores. During this…

Astrophysics of Galaxies · Physics 2015-06-12 Philip C. Myers

Using molecular line data from the Millimetre Astronomy Legacy Team 90 GHz Survey (MALT90), we have searched the optically thick \hcop\, line for the "blue asymmetry" spectroscopic signature of infall motion in a large sample of high-mass,…

We summarize the current status of the turbulent model of star formation in turbulent molecular clouds. In this model, clouds, clumps and cores form a hierarchy of nested density fluctuations caused by the turbulence, and either collapse or…

Astrophysics · Physics 2007-05-23 Enrique Vazquez-Semadeni

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 SMA and CARMA continuum and spectral line observations of five dense cores located in the Perseus and Ophiuchus molecular clouds whose masses exceed their thermal Jeans masses. Three of these cores have previously been identified…

Solar and Stellar Astrophysics · Physics 2015-06-05 Scott Schnee , Sarah Sadavoy , James Di Francesco , Doug Johnstone , Lisa Wei

We have observed the HCO+ J=3-2 line toward 17 starless cores selected from the list of Ward-Thompson et al. (1994). Six of these cores have line asymmetries indicative of collapse. The excess of blue-skewed profiles over red-skewed…

Astrophysics · Physics 2009-10-31 Erik M. Gregersen , Neal J. Evans