J/A+A/650/A59 HD 142527 disk 13CO and C18O images (Boehler+, 2021)
Vortex-like kinematic signal, spirals, and beam smearing effect in the
HD 142527 disk
Boehler Y., Menard F., Robert C.M.T., Isella A., Pinte C.,
Gonzalez J.-F., van der Plas G., Weaver E., Teague R., Garg H., Meheut H.
<Astron. Astrophys. 650, A59 (2021)>
=2021A&A...650A..59B 2021A&A...650A..59B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Stars, pre-main sequence ; Carbon monoxide
Keywords: protoplanetary disks - submillimetre: planetary systems -
stars: individual: HD 142527 - methods: observational
Abstract:
Vortices are one of the most promising mechanisms to locally
concentrate millimeter dust grains and allow the formation of
planetesimals through gravitational collapse. The outer disk around
the binary system HD 142527 is known for its large horseshoe structure
with azimuthal contrasts of ∼3-5 in the gas surface density and of
∼50 in the dust. Using 13CO and C18O J=3-2 transition lines, we
detect kinematic deviations to the Keplerian rotation, which are
consistent with the presence of a large vortex around the dust
crescent, as well as a few spirals in the outer regions of the disk.
Comparisons with a vortex model suggest velocity deviations up to
350m/s after deprojection compared to the background Keplerian
rotation, as well as an extension of ±40au radially and ∼200°
azimuthally, yielding an azimuthal-to-radial aspect ratio of ∼5.
Another alternative for explaining the vortex-like signal implies
artificial velocity deviations generated by beam smearing in
association with variations of the gas velocity due to gas pressure
gradients at the inner and outer edges of the circumbinary disk. The
two scenarios are currently difficult to differentiate and, for this
purpose, would probably require the use of multiple lines at a higher
spatial resolution. The beam smearing effect, due to the finite
spatial resolution of the observations and gradients in the line
emission, should be common in observations of protoplanetary disks and
may lead to misinterpretations of the gas velocity, in particular
around ring-like structures.
Description:
These dada were obtained throuth the ALMA project 2012.1.00725.S. The
observations were carried on 2015 June 13th in dual polarization with
a total time of ∼2.9 hours and ∼1.1 hour on target, using 37
antennas on projected baselines between 35 and 770 meters. Our data
contain 4 GHz bandwidth in continuum in the frequency range of
340-344GHz. The 13CO J=3-2 and C18O J=3-2 were also observed, with
rest frequencies 330.58797GHz and 329.33055GHz respectively, using a
channel width of 130kHz after Hanning smoothing (∼0.11km/s).
Objects:
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RA (2000) DE Designation(s)
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15 56 41.89 -42 19 23.2 HD 142527 = HIP 78092
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 186 5 List of fits images
fits/* . 5 Individual fits images
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See also:
J/A+A/546/A24 : VLT/NaCo images of HD 142527 (Rameau+, 2012)
J/A+A/556/A123 : Near-IR imaging polarimetry of HD142527 (Canovas+, 2013)
J/A+A/622/A96 : HD142527B images with SPHERE (Claudi+, 2019)
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- 50 A23 "datime" Obs.date Observation date
52- 58 F7.3 GHz Freq Observed frequency
60- 63 I4 Kibyte size Size of FITS file
65- 84 A20 --- FileName Name of FITS file, in subdirectory fits
86-186 A101 --- Title Title of the FITS file
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Acknowledgements:
Yann Boehler, y04.boehler(at)gmail.com
(End) Patricia Vannier [CDS] 06-Apr-2021