J/A+A/610/A24 AS 209 ALMA image (Fedele+, 2018)
ALMA continuum observations of the protoplanetary disk AS 209.
Evidence of multiple gaps opened by a single planet.
Fedele D., Tazzari M., Booth R., Testi L., Clarke C.J., Pascucci I.,
Kospal A., Semenov D., Bruderer S., Henning T., Teague R.
<Astron. Astrophys. 610, A24 (2018)>
=2018A&A...610A..24F 2018A&A...610A..24F (SIMBAD/NED BibCode)
ADC_Keywords: YSOs ; Exoplanets ; Radio continuum
Keywords: protoplanetary disks - planet-disk interactions
Abstract:
This paper presents new high angular resolution ALMA 1.3mm dust
continuum observations of the protoplanetary system AS 209 in the
Ophiuchus star forming region. The dust continuum emission is
characterized by a main central core and two prominent rings at r=75au
and r=130au intervaled by two gaps at at r=62au and r=103au. The two
gaps have different widths and depths, with the inner one being
narrower and shallower. We determined the surface density of the
millimeter dust grains using the 3D radiative transfer disk code dali.
According to our fiducial model the inner gap is partially filled with
millimeter grains while the outer gap is largely devoid of dust. The
inferred surface density is compared to 3D hydrodynamical simulations
(FARGO-3D) of planet-disk interaction. The outer dust gap is
consistent with the presence of a giant planet
(Mplanet∼0.8MSaturn); the planet is responsible for the gap
opening and for the pile-up of dust at the outer edge of the planet
orbit. The simulations also show that the same planet could be the
origin of the inner gap at r=62au. The relative position of the two
dust gaps is close to the 2:1 resonance and we have investigated the
possibility of a second planet inside the inner gap. The resulting
surface density (including location, width and depth of the two dust
gaps) are in agreement with the observations. The properties of the
inner gap pose a strong constraint to the mass of the inner planet
(Mplanet<0.1MJ). In both scenarios (single or pair of planets),
the hydrodynamical simulations suggest a very low disk viscosity
(α<10-4). Given the young age of the system (0.5-1Myr), this
result implies that the formation of giant planets occurs on a
timescale of ≲1Myr.
Description:
The ALMA observations of AS 209 (J2000: RA=16:49:15.296,
DE=-14:22:09.02) have been performed on 2016 September 22 (with 38
antennas) and 26 (41 antennas) in band 6 (211-275GHz) as part of the
project ID 2015.1.00486.S (PI: D. Fedele). The correlator setup
includes a broad (2GHz bandwidth) spectral window centered at 230GHz.
Objects:
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RA (2000) DE Designation(s)
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16 49 15.30 -14 22 08.6 AS 209 = V* V1121 Oph
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 127 1 Information on fits image
fits/* . 1 Fits image
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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- 23 I4 --- Nx Number of pixels along X-axis
25- 28 I4 --- Ny Number of pixels along Y-axis
30- 55 A26 --- Obs.Date Observation date (YYYY-MM-DDThh:mm:ss.ssssss)
57- 63 F7.3 GHz Freq Observed frequency
65- 68 I4 Kibyte size Size of FITS file
70-115 A46 --- FileName Name of FITS file, in subdirectory fits
117-127 A11 --- Title Title of the FITS file
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Acknowledgements:
Davide Fedele, fedele(at)arcetri.astro.it
(End) Patricia Vannier [CDS] 14-Feb-2018