Multi-wavelength observations and modelling of a quiescent cloud LDN1512
| Autor: | Charlène Lefèvre, Nathalie Ysard, Mika Juvela, Laurent Pagani, Mika Saajasto |
|---|---|
| Přispěvatelé: | Institut de RadioAstronomie Millimétrique (IRAM), Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Physics |
| Rok vydání: | 2021 |
| Předmět: |
010504 meteorology & atmospheric sciences
FOS: Physical sciences Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics ISM: clouds 01 natural sciences Light scattering 0103 physical sciences Thermal Radiative transfer Black-body radiation 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics 0105 earth and related environmental sciences Cosmic dust Physics stars: formation [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] Scattering Molecular cloud scattering Astronomy and Astrophysics 115 Astronomy Space science Astrophysics - Astrophysics of Galaxies radiation mechanisms: thermal Interstellar medium radiative transfer [SDU]Sciences of the Universe [physics] 13. Climate action Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) Astrophysics::Earth and Planetary Astrophysics |
| Zdroj: | Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, EDP Sciences, 2021, 647, pp.A109. ⟨10.1051/0004-6361/202038401⟩ |
| ISSN: | 1432-0746 0004-6361 |
| DOI: | 10.1051/0004-6361/202038401 |
| Popis: | Light scattering at near-infrared wavelengths has been used to study the optical properties of the interstellar dust grains, but these studies are limited by the assumptions on the strength of the radiation field. On the other hand, thermal dust emission can be used to constrain the properties of the radiation field, although this is hampered by uncertainty about the dust emissivity. We test if current dust models allow us to model a molecular cloud simultaneously in the near infrared (NIR) and far infrared (FIR) wavelengths and compare the results with observations. Our aim is to place constraints on the properties of the dust grains and the strength of the radiation field. We present computations of dust emission and scattered light of a quiescent molecular cloud LDN1512. We construct radiative transfer models for LDN1512 that include an anisotropic radiation field and a three-dimensional cloud model. We are able to reproduce the observed FIR observations, with a radiation field derived from the DIRBE observations, with all of the tested dust models. However, with the same density distribution and the assumed radiation field, the models fail to reproduce the observed NIR scattering in all cases except for models that take into account dust evolution via coagulation and mantle formation. We find that the column densities derived from our radiative transfer modelling can differ by a factor of up to two, compared to the column densities derived from the observations with modified blackbody fits. The discrepancy in the column densities is likely caused because of temperature difference between a modified blackbody fit and the real spectra. We show that the observed dust emission can be reproduced with several different assumptions about the properties of the dust grains. However, in order to reproduce the observed scattered surface brightness dust evolution must be taken into account. Comment: 16 pages, 16 figures. Recommended for publication to A&A |
| Databáze: | OpenAIRE |
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