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Related papers: Dust opacity variations in the pre-stellar core L1…

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In dense and cold molecular clouds dust grains are surrounded by thick icy mantles. It is however not clear if dust growth and coagulation take place before the switch-on of a protostar. This is an important issue, as the presence of large…

Astrophysics of Galaxies · Physics 2017-11-07 A. Chacón-Tanarro , P. Caselli , L. Bizzocchi , J. E. Pineda , J. Harju , M. Spaans , F. -X. Désert

We develop a self-consistent model for the equilibrium gas temperature and size-dependent dust temperature in cold, dense pre-stellar cores, assuming an arbitrary power-law size distribution of dust grains. Compact analytical expressions…

Astrophysics of Galaxies · Physics 2019-11-06 Alexei V. Ivlev , Kedron Silsbee , Olli Sipilä , Paola Caselli

We have computed the dust temperature distribution to be expected in a pre-protostellar core in the phase prior to the onset of gravitational instability. We have done this in the approximation that the heating of the dust grains is solely…

Astrophysics · Physics 2009-11-06 A. Zucconi , C. M. Walmsley , D. Galli

Pre-stellar cores are the basic unit for the formation of stars and stellar systems. The anatomy of the physical and chemical structures of pre-stellar cores is critical for understanding the star formation process. L1544 is a prototypical…

Astrophysics of Galaxies · Physics 2022-09-21 Yuxin Lin , Silvia Spezzano , Olli Sipilä , Anton Vasyunin , Paola Caselli

We observed the pre-stellar core L1521F in dust emission at 1.2mm and in two transitions each of N2H+, N2D+, C18O, and C17O in order to increase the sample of well studied centrally concentrated and chemically evolved starless cores, likely…

Astrophysics · Physics 2009-11-10 A. Crapsi , P. Caselli , C. M. Walmsley , M. Tafalla , C. W. Lee , T. L. Bourke , P. C. Myers

Prestellar cores are unique laboratories for studies of the chemical and physical conditions preceding star formation. We observed the prestellar core L1544 in the fundamental transition of ortho-H2D+ (1_1,0-1_1,1) at different positions…

Astrophysics · Physics 2009-11-11 C. Vastel , P. Caselli , C. Ceccarelli , T. G. Phillips , M. Wiedner , R. peng , M. Houde , C. Dominik

We observed the L1506 filament, which is located in the Taurus molecular complex, with the Herschel PACS and SPIRE instruments. Our aim is to prove the variation in grain properties along the entire length of the filament. In particular, we…

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 have mapped the dense dark core L1544 in H13CO+(1-0), DCO+(2-1), DCO+(3-2), N2H+(1-0), NTH+(3-2), N2D+(2-1), N2D+(3-2), C18O(1-0), and C17O(1-0) using the IRAM 30-m telescope. We have obtained supplementary observations of HC18O+(1-0),…

Astrophysics · Physics 2019-08-17 P. Caselli , C. M. Walmsley , A. Zucconi , M. Tafalla , L. Dore , P. C. Myers

We have modeled the emission from dust in pre-protostellar cores, including a self-consistent calculation of the temperature distribution for each input density distribution. Model density distributions include Bonnor-Ebert spheres and…

Astrophysics · Physics 2009-11-06 Neal J. Evans , Jonathan M. C. Rawlings , Yancy L. Shirley , Lee G. Mundy

The detection of complex organic molecules (COMs) toward cold sources such as pre-stellar cores (with T<10 K), has challenged our understanding of the formation processes of COMs in the interstellar medium. Recent modelling on COM chemistry…

Abridged: The thermal structure of a starless core is crucial for our understanding of the physics in these objects and hence for our understanding of star formation. Theory predicts a gas temperature drop in the inner 5000 AU of these…

Astrophysics · Physics 2009-11-13 Antonio Crapsi , Paola Caselli , Malcolm C. Walmsley , Mario Tafalla

Dust grains play a key role in the physics of star-forming regions, even though they constitute only $\sim$1 % of the mass of the interstellar medium. The derivation of accurate dust parameters such as temperature ($T_{dust}$), emissivity…

We have compared molecular line emission to dust continuum emission and modeled molecular lines using Monte Carlo simulations in order to study the depletion of molecules and the ionization fraction in three preprotostellar cores, L1512,…

Astrophysics · Physics 2009-11-07 Jeong-Eun Lee , Neal J. Evans , Yancy L. Shirley , Ken'ichi Tatematsu

We aim to explore the capabilities of dust emission and rays for probing the properties of the interstellar medium in the nearby anti-centre region, using gamma-ray observations with the Fermi Large Area Telescope (LAT), and the thermal…

High Energy Astrophysical Phenomena · Physics 2017-05-10 Q. Remy , I. A. Grenier , D. J. Marshall , J. M. Casandjian

We have studied the opacity of dust grains at submillimeter wavelengths by estimating the optical depth from imaging at 160, 250, 350, and 500 um from the Herschel Gould Belt Survey and comparing this to a column density obtained from the…

Stars like our Sun form in self-gravitating dense and cold structures within interstellar clouds, called pre-stellar cores. Although much is known about the physical structure of dense clouds just before and soon after the switch-on of a…

Using the APEX-12m telescope, continuum maps at 350~$\mu$m of eight gas-dust clouds from the southern hemisphere are obtained. Clouds are associated with the regions of massive star and star cluster formation and have dense cores. Core…

Astrophysics of Galaxies · Physics 2023-01-12 L. E. Pirogov

Pre-stellar cores represent the initial conditions in the process of star and planet formation. Their low temperatures ($<$10 K) allow the formation of thick icy dust mantles, which will be partially preserved in the future protoplanetary…

Within the project Galactic Cold Cores we are carrying out Herschel photometric observations of cold interstellar clouds detected with the Planck satellite. The three fields observed as part of the Herschel science demonstration phase (SDP)…

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