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Related papers: Internal Motions in Starless Dense Cores

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In a previous paper we identified cores within infrared dark clouds (IRDCs). We regarded those without embedded sources as the least evolved, and labelled them starless. Here we identify the most isolated starless cores and model them using…

AIMS: To study the structure of nearby (< 500 pc) dense starless and star-forming cores with the particular goal to identify and understand evolutionary trends in core properties, and to explore the nature of Very Low Luminosity Objects (<…

Astrophysics · Physics 2009-11-13 Jens Kauffmann , Frank Bertoldi , Tyler L. Bourke , Neal J. Evans , Chang Won Lee

We present Submillimeter Array (SMA) observations of seven massive molecular clumps which are dark in the far-infrared for wavelengths up to 70 $\mu$m. Our 1.3 mm continuum images reveal 44 dense cores, with gas masses ranging from 1.4 to…

Astrophysics of Galaxies · Physics 2019-12-11 Shanghuo Li , Qizhou Zhang , Thushara Pillai , Ian W. Stephens , Junzhi Wang , Fei Li

Aims: We derive the probability density functions (PDFs) of column density for a complete sample of prominent molecular cloud complexes closer than 200 pc. Methods: We derive near-infrared dust extinction maps for 23 molecular cloud…

Astrophysics of Galaxies · Physics 2015-05-14 J. Kainulainen , H. Beuther , T. Henning , R. Plume

Oscillation modes of a mixed character are able to probe the inner region of evolved low-mass stars and offer access to a range of information, in particular, the mean core rotation. Ensemble asteroseismology observations are then able to…

Solar and Stellar Astrophysics · Physics 2024-01-17 B. Mosser , G. Dreau , C. Pincon , S. Deheuvels , K. Belkacem , Y. Lebreton , M-J. Goupil , E. Michel

Dense cores in massive, parsec-scale molecular clumps are sites that harbor protocluster formation. We present results from observations towards a hub-filament structure of a massive Infrared Dark Cloud (IRDC) G14.225-0.506 using the…

Astrophysics of Galaxies · Physics 2025-03-14 Yanhanle Zhao , Qizhou Zhang , Junhao Liu , Xing Pan , Lingzhen Zeng

We present results of a long-slit spectroscopic study of 39 active and 3 normal galaxies. Stellar absorption features, continuum colors and their radial variations are analyzed in an effort to characterize the stellar population in these…

Astrophysics · Physics 2009-10-30 Roberto Cid Fernandes , Thaisa Storchi-Bergmann , Henrique R. Schmitt

We aim to investigate the polarization properties of a starless core in a very early evolutionary stage. Linear polarization data reveal the properties of the dust grains in the distinct phases of the interstellar medium. Our goal is to…

Solar and Stellar Astrophysics · Physics 2014-09-17 Felipe Alves , Pau Frau , Josep M. Girart , Gabriel A. P. Franco , Fábio P. Santos , Helmut Wiesemeyer

We have characterized the physical structure and chemical composition of two close-to-round starless cores in Taurus-Auriga, L1498 and L1517B. Our analysis is based on high angular resolution observations in at least two transitions of NH3,…

Astrophysics · Physics 2009-11-10 M. Tafalla , P. C. Myers , P. Caselli , C. M. Walmsley

Low-mass stars are generally understood to form by the gravitational collapse of the dense molecular clouds known as starless cores. Continuum observations have not been able to distinguish among the several different hypotheses that…

Solar and Stellar Astrophysics · Physics 2015-06-23 Eric Keto , Paola Caselli , Jonathan Rawlings

Observations of the Pipe Nebula have led to the discovery of dense starless cores. The mass of most cores is too small for their self gravity to hold them together. Instead, they are thought to be pressure confined. The observed dense…

Astrophysics of Galaxies · Physics 2015-06-15 Xu Huang , Tingtao Zhou , D. N. C. Lin

[Abridged] We present a molecular survey of the starless cores L1498 and L1517B. These cores have been selected for their relative isolation and close-to-round shape, and they have been observed in a number of lines of 13 molecular species…

Astrophysics · Physics 2009-11-11 M. Tafalla , J. Santiago , P. C. Myers , P. Caselli , C. M. Walmsley , A. Crapsi

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

We have coupled a chemical model with two dynamical models of collapsing low mass star-forming cores to predict abundances across the core of the commonly used infall tracers, CS and HCO$^+$, at various stages of the collapse. The models…

Solar and Stellar Astrophysics · Physics 2015-05-19 Julia F. Roberts , Hugh A. W. Stace , Jonathan M. C. Rawlings

Useful information from the inner layers of stellar pulsators may be derived from the study of their oscillations. In this paper we analyse three diagnostic tools suggested in the literature built from the oscillation frequencies computed…

Solar and Stellar Astrophysics · Physics 2015-05-19 I. M. Brandão , M. S. Cunha , O. L. Creevey , J. Christensen-Dalsgaard

Asteroseismology of solar-type stars is an important tool for constraining stellar parameters and internal structure. Several frequency combinations are largely used for comparisons between models and observations. In particular, the…

Astrophysics · Physics 2009-11-13 M. Soriano , S. Vauclair

A survey of 28 stars using EUV spectra has been conducted to establish the structure of stellar coronae in active binary systems from the EMD, electron densities, and scale sizes. Observations obtained by the EUVE during 9 years of…

Astrophysics · Physics 2009-11-07 J. Sanz-Forcada , N. S. Brickhouse , A. K. Dupree

Dense molecular filaments are central to the star formation process, but the detailed manner in which they fragment into prestellar cores is not yet well understood. Here, we investigate the fragmentation properties and dynamical state of…

Solar and Stellar Astrophysics · Physics 2020-10-07 Guo Yin Zhang , Ph. Andre , A. Menshchikov , Ke Wang

We present numerical investigations into the formation of massive stars from centrally condensed turbulent cores. The results of five hydrodynamical simulations are described, following the collapse of the core, fragmentation and the…

Astrophysics · Physics 2009-11-10 Clare L. Dobbs , Ian A. Bonnell , Paul C. Clark

Stars form from dense cores in turbulent molecular clouds. According to the standard scenario of star formation, dense cores are created by cloud fragmentation. However, the physical mechanisms driving this process are still not fully…

Astrophysics of Galaxies · Physics 2025-03-11 Kousuke Ishihara , Fumitaka Nakamura , Patricio Sanhueza , Masao Saito