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Related papers: An analytic column density profile to fit prestell…

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Constraining the physical and chemical evolution of molecular clouds is essential to our understanding of star formation. These investigations often necessitate knowledge of some local representative number density of the gas along the line…

Astrophysics of Galaxies · Physics 2025-04-02 Brandt A. L. Gaches , Michael Y. Grudić

We aim to reveal the physical properties and chemical composition of the cores in the California molecular cloud (CMC), so as to better understand the initial conditions of star formation. We made a high-resolution column density map…

We present a catalogue of dense cores identified in James Clerk Maxwell Telescope (JCMT) Gould Belt Survey SCUBA-2 observations of nearby star-forming clouds. We identified 2257 dense cores using the getsources algorithm, of which 59% are…

Measurement of internal structures in the prestellar core is essential for understanding the initial conditions prior to star formation. In this work,, we study the ammonia lines (NH3 ) (J,K=1,1 and 2,2) in the central region of the…

Astrophysics of Galaxies · Physics 2023-10-24 Atanu Koley

We develop analytic approximations to the density evolution of prestellar cores, based on the results of hydrodynamical simulations. We use these approximations as input for a time-dependent gas-grain chemical code to investigate the…

Astrophysics of Galaxies · Physics 2018-07-25 F. D. Priestley , S. Viti , D. A. Williams

Herschel has revolutionized our ability to measure column densities (N$_{\rm H}$) and temperatures (T) of molecular clouds thanks to its far infrared multiwavelength coverage. However, the lack of a well defined background intensity level…

Instrumentation and Methods for Astrophysics · Physics 2017-08-09 J. Abreu-Vicente , A. Stutz , Th. Henning , E. Keto , J. Ballesteros-Paredes , T. Robitaille

We have mapped linearly polarized dust emission from the prestellar cores L1498 and L1517B with the James Clerk Maxwell Telescope (JCMT) using the Submillimetre Common User Bolometer Array (SCUBA) and its polarimeter SCUBAPOL at a…

Astrophysics · Physics 2009-11-11 Jason M. Kirk , Derek Ward-Thompson , Richard M. Crutcher

The density and temperature structures of dense cores in the L1495 cloud of the Taurus star-forming region are investigated using Herschel SPIRE and PACS images in the 70 $\mu$m, 160 $\mu$m, 250 $\mu$m, 350 $\mu$m and 500 $\mu$m continuum…

We present new observations of the CB130 region, composed of three separate cores. Using the \textit{Spitzer Space Telescope} we detected a Class 0 and a Class II object in one of these, CB130-1. The observed photometric data from…

We study the estimation, in Lp-norm, of density functions defined on [0,1]^d. We construct a new family of kernel density estimators that do not suffer from the so-called boundary bias problem and we propose a data-driven procedure based on…

Statistics Theory · Mathematics 2018-10-29 Karine Bertin , Salima El Kolei , Nicolas Klutchnikoff

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

Under the assumptions that molecular clouds are nearly spatially and temporally isothermal and that the density peaks (``cores'') within them are formed by turbulent fluctuations, we argue that cores cannot reach a hydrostatic (or…

Two different formalisms for the homogenization of composite materials containing ellipsoidal inclusions based on Bruggeman's original formula for spherical inclusions can be found in the literature. Both approximations determine the…

Optics · Physics 2013-09-13 Daniel Schmidt , Mathias Schubert

We present 2D Monte Carlo radiative transfer simulations of prestellar cores. We consider two types of asymmetry: disk-like asymmetry, in which the core is denser towards the equatorial plane than towards the poles; and axial asymmetry, in…

Astrophysics · Physics 2009-11-10 D. Stamatellos , A. P. Whitworth , P. Andre , D. Ward-Thompson

Flat density cores have been obtained for a limited number of clusters of galaxies by strong gravitational lensing. This paper explores the possibility that the degeneracy pressure of fermionic dark matter accounts for the flat top density…

Astrophysics · Physics 2008-11-26 Tadashi Nakajima , Masahiro Morikawa

We present results from the first three-dimensional calculations ever to follow the collapse of a molecular cloud core (~ 10^{-18} g cm^{-3}) to stellar densities (> 0.01 g cm^{-3}). The calculations resolve structures over 7 orders of…

Astrophysics · Physics 2009-10-31 Matthew R. Bate

We used FIR and submillimeter continuum data from Herschel and the Atacama Pathfinder EXperiment (APEX) to fit pixel-by-pixel modified Planck SEDs to prestellar and protostellar clumps in the Census of High- and Medium-mass Protostars…

Astrophysics of Galaxies · Physics 2019-01-09 Rebecca L. Pitts , Peter J. Barnes , Frank Varosi

We present an analysis of polarised dust emission at 850 micron for a parsec long filament in the northern part of the Orion B molecular cloud. The region was observed by the JCMT SCUBA-2/POL-2 polarimeter. The filament has a line mass (~80…

Aims. We aim to improve a previous model for the prediction of column densities and deuterium fractions of non- and singly deuterated methanol. Thereby, we try to identify crucial chemical and physical parameters, for which the study of…

Astrophysics of Galaxies · Physics 2023-12-20 W. Riedel , O. Sipilä , E. Redaelli , P. Caselli , A. I. Vasyunin , F. Dulieu , N. Watanabe

Recent high-resolution studies of the L1544 protostellar core by Tafalla et al. and Williams et al. reveal the structure and kinematics of the gas. The observations of this prestellar core provide a natural test for theoretical models of…

Astrophysics · Physics 2009-10-31 Glenn E. Ciolek , Shantanu Basu