J/A+A/623/A118 Dust opacity variations in L1544 (Chacon-Tanarro+, 2019)
Dust opacity variations in the pre-stellar core L1544.
Chacon-Tanarro A., Pineda J.E., Caselli P., Bizzocchi L., Gutermuth R.A.,
Mason B.S., Gomez-Ruiz A.I., Harju J., Devlin M., Dicker S.R.,
Mroczkowski T., Romero C.E., Sievers J., Stanchfield S., Offner S.,
Sanchez-Arguelles D.
<Astron. Astrophys. 623, A118 (2019)>
=2019A&A...623A.118C 2019A&A...623A.118C (SIMBAD/NED BibCode)
ADC_Keywords: Molecular clouds ; Interstellar medium
Keywords: ISM: clouds - ISM: individual objects: L1544 - extinction - opacity -
stars: formation
Abstract:
The study of dust emission at millimeter wavelengths is important to
shed light on the dust properties and physical structure of
pre-stellar cores, the initial conditions in the process of star and
planet formation.
Using two new continuum facilities, AzTEC at the Large Millimeter
Telescope Alfonso Serrano and MUSTANG-2 at the Green Bank Observatory,
we aim to detect changes in the optical properties of dust grains as a
function of radius for the well-known pre-stellar core L1544.
We determined the emission profiles at 1.1 and 3.3mm and examine
whether they can be reproduced in terms of the current best physical
models for L1544. We also made use of various tools to determine the
radial distributions of the density, temperature, and dust opacity in
a self-consistent manner.
We find that our observations cannot be reproduced without invoking
opacity variations. New temperature and density profiles, as well as
opacity variations across the core, have been derived with the new
data. The opacity changes are consistent with the expected variations
between uncoagulated bare grains, toward the outer regions of the
core, and grains with thick ice mantles, toward the core center. A
simple analytical grain growth model predicts the presence of grains
of 3-4um within the central 2000 au for the new density profile.
Description:
Millimeter observations of the pre-stellar core L1544 are presented.
These observations were carried out at the Green Bank Observatory and
the Large Millimeter Telescope Alfonso Serrano using the cameras
MUSTANG-2 and AzTEC, respectively. The main beam widths are
12.6-arcsec at 1.1mm and 9.7-arcsec at 3.3mm.
Objects:
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RA (2000) DE Designation(s)
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05 04 16.6 +25 10 48 L1544 = LDN 1544
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 66 2 List of fits images
fits/* . 2 Individual fits images
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28- 31 I4 Kibyte size Size of FITS file
33- 44 A12 --- FileName Name of FITS file, in subdirectory fits
46- 66 A21 --- Title Title of the FITS file
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Acknowledgements:
Ana Chacon-Tanarro, a.chacon(at)oan.es
(End) Patricia Vannier [CDS] 26-Feb-2019