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Related papers: Grain Alignment in Starless Cores

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The Pipe nebula is a massive, nearby, filamentary dark molecular cloud with a low star-formation efficiency threaded by a uniform magnetic field perpendicular to its main axis. It harbors more than a hundred, mostly quiescent, very…

We extend and investigate the spheroidal model of interstellar dust grains used to simultaneously interpret the observed interstellar extinction and polarization curves. We compare our model with similar models recently suggested by other…

Astrophysics of Galaxies · Physics 2015-05-14 H. K. Das , N. V. Voshchinnikov , V. B. Il'in

We present the polarization maps of three selected Bok globules CB56, CB60 and CB69 constructed using a V-band data from a CCD imaging polarimeter. The aim of this work is to measure the optical polarization ($p_v$) of background field…

Solar and Stellar Astrophysics · Physics 2014-05-28 A. Chakraborty , H. S. Das , D. Paul

Context. Planck observations demonstrated that the grain alignment efficiency is almost constant in the diffuse ISM. Aims. We test if the Radiative Torque (RAT) theory is compatible with observational constraints on grain alignment.…

Instrumentation and Methods for Astrophysics · Physics 2020-08-26 Stefan Reissl , Vincent Guillet , Robert Brauer , François Levrier , François Boulanger , Ralf S. Klessen

The results of a near-infrared (J H K LP) imaging linear polarimetry survey of 20 young stellar objects (YSOs) in rho Ophiuchi are presented. The majority of the sources are unresolved, with K-band polarizations, P_K < 6 per cent. Several…

Astrophysics · Physics 2009-11-13 A. F. Beckford , P. W. Lucas , A. C. Chrysostomou , T. M. Gledhill

We present a statistical analysis of the interstellar medium (ISM) polarization from the largest compilation available of starlight data, which comprises ~ 5500 stars. The measured correlation between the mean polarization degree and…

Astrophysics · Physics 2014-10-13 Pablo Fosalba , Alex Lazarian , Simon Prunet , Jan A. Tauber

Recent observational progress has challenged the dust grain-alignment theories used to explain the polarized dust emission routinely observed in star-forming cores. In an effort to improve our understanding of the dust grain alignment…

We present new results on CO depletion in a sample of nearby pre-stellar cores, based on observations of the millimeter C17O and C18O lines and the 1.3 mm dust emission with the IRAM 30m telescope. In most cases, the distribution of CO is…

The recent detection of interstellar polarization in the solid CO feature near 4.67 micron shows that CO-mantled grains can be aligned in cold molecular clouds. These observations conflict with a theory of grain alignment which attributes…

Astrophysics · Physics 2015-06-24 A. Lazarian , W. G. Roberge

Interstellar polarization from aligned dust grains can be measured both in transmission at visible and near-infrared wavelengths and in emission at far-infrared and sub-mm wavelengths. These observations can help predict the behavior of…

Astrophysics · Physics 2015-06-24 Terry J. Jones

Recently discovered scattered light from molecular cloud cores in the wavelength range 3-5 {\mu}m (called "coreshine") seems to indicate the presence of grains with sizes above 0.5 {\mu}m. We aim to analyze 3.6 and 4.5 {\mu}m coreshine from…

Solar and Stellar Astrophysics · Physics 2015-10-21 J. Steinacker , M. Andersen , W. -F. Thi , R. Paladini , M. Juvela , A. Bacmann , V. -M. Pelkonen , L. Pagani , C. Lefèvre , Th. Henning , A. Noriega-Crespo

For aspherical interstellar dust grains aligned with their short axes preferentially parallel to the local magnetic field, the amount of extinction per grain is larger when the magnetic field is along the line of sight and smaller when in…

Astrophysics of Galaxies · Physics 2024-11-27 Brandon S. Hensley

We present results of an extensive mapping survey of N2H+(1-0) in about 60 low mass cloud cores already mapped in the NH3(1,1) inversion transition line. The survey has been carried out at the FCRAO antenna with an angular resolution about…

Astrophysics · Physics 2010-04-06 Paola Caselli , Priscilla J. Benson , Philip C. Myers , Mario Tafalla

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

Aligned interstellar grains produce polarized extinction (observed at wavelengths from the far-ultraviolet to the mid-infrared), and polarized thermal emission (observed at far-infrared and submm wavelengths). The grains must be quite…

Astrophysics of Galaxies · Physics 2025-04-07 B. T. Draine

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

ALMA observations revealed recently polarised radiation of several protoplanetary disks in the (sub-)millimetre wavelength range. Besides self-scattering of large particles, thermal emission by elongated grains is a potential source for the…

Earth and Planetary Astrophysics · Physics 2019-07-10 Florian Kirchschlager , Gesa H. -M. Bertrang , Mario Flock

We have investigated the grain alignment and dust properties towards the direction of the cluster NGC 2345 using the multi-band optical polarimetric observations. For the majority of the stars, the observed polarization is found to be due…

Astrophysics of Galaxies · Physics 2022-06-01 Sadhana Singh , Jeewan C. Pandey , Thiem Hoang

Recently, Maiolino et al. (2001a, A&A, 365, 28) constructed a sample of active galactic nuclei for which both the reddening E(B-V) and the column density N_H to the nucleus could be determined. For most of the galaxies in their sample, they…

Astrophysics · Physics 2009-11-07 Joseph C. Weingartner , Norman Murray