J/ApJ/860/124 ALMA continuum emission obs. of MWC 758 disk (Dong+, 2018)
The eccentric cavity, triple rings, two-armed spirals, and double clumps of the
MWC 758 disk.
Dong R., Liu S.-Y., Eisner J., Andrews S., Fung J., Zhu Z., Chiang E.,
Hashimoto J., Liu H.B., Casassus S., Esposito T., Hasegawa Y., Muto T.,
Pavlyuchenkov Y., Wilner D., Akiyama E., Tamura M., Wisniewski J.
<Astrophys. J., 860, 124 (2018)>
=2018ApJ...860..124D 2018ApJ...860..124D
ADC_Keywords: YSOs; Millimetric/submm sources
Keywords: planet-disk interactions ; planets and satellites: formation ;
protoplanetary disks ; stars: individual (MWC 758) ;
stars: variables: T Tauri, Herbig Ae/Be
Abstract:
Spatially resolved structures in protoplanetary disks hint at unseen
planets. Previous imaging observations of the transitional disk around
MWC 758 revealed an inner cavity, a ring-like outer disk, emission
clumps, and spiral arms, all possibly generated by companions. We
present ALMA dust continuum observations of MWC 758 at 0.87mm
wavelength with 43x39mas angular resolution (6.9x6.2au) and
20µJy/beam rms. The central submillimeter emission cavity is
revealed to be eccentric; once deprojected, its outer edge can be well
fitted by an ellipse with an eccentricity of 0.1 and one focus on the
star. The broad ring-like outer disk is resolved into three narrow
rings with two gaps in between. The outer two rings tentatively show
the same eccentricity and orientation as the innermost ring bounding
the inner cavity. The two previously known dust emission clumps are
resolved in both the radial and azimuthal directions, with radial
widths equal to ∼4x the local scale height. Only one of the two spiral
arms previously imaged in near-infrared (NIR) scattered light is
revealed in ALMA dust emission, at a slightly larger stellocentric
distance owing to projection effects. We also submit evidence of disk
truncation at ∼100au based on comparing NIR imaging observations with
models. The spirals, the north clump, and the truncated disk edge are
all broadly consistent with the presence of one companion exterior to
the spirals at roughly 100au.
Description:
Our observations, including three execution blocks (EBs) toward
MWC758, were carried out in Cycle 5 by ALMA under project 2017.1.00492.S.
The first EB was conducted on 2017 November 12 with 48 antennas in the
array configuration C43-8. The other two EBs were conducted on 2017
November 25 with 48 and 49 antennas in the same C43-8 array
configuration. The combined data set has baselines ranging between 92m
and 11.84km, which correspond to angular scales between ∼1.8" and 0.009".
The total integration time on source is about 125min.
Four spectral windows centered at 336.495, 338.432, 348.495, and
350.495GHz, each with an effective bandwidth of 1.78125GHz and 128
spectral channels under the time division mode (TDM), were employed to
maximize the continuum sensitivity.
Objects:
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RA (ICRS) DE Designation(s)
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05 30 27.53 +25 19 57.1 MWC 758 = HD 36112
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fits.dat 95 2 Summary of the FITS files in subdirectory fits
fits/* . 2 Individual FITS files
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Description of files:
Fig1.fits is the FITS file for Figure 1(a). The data reduction is
described in Section 2. Briefly, we used the Briggs weighting scheme
with a robust parameter of 0.5 and an additional uv-tapering,
resulting in a synthesized beam size of 43x39mas at PA=-4.3deg.
Natural_Weighting.fits is the FITS file of an alternative version of
the synthesized image with the standard natural weighting scheme,
which results in a synthesized beam size of 52x42mas at PA=-7.1deg.
This version is not shown in the paper.
See also:
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
J/ApJ/745/174 : Evolutionary models of young gas-giant planets (Spiegel+, 2012)
J/A+A/556/A123 : Near-IR imaging polarimetry of HD142527 (Canovas+, 2013)
J/A+A/560/A105 : SAO 206462 polarised Ks image (Garufi+, 2013)
J/A+A/578/L6 : Polarized images of MWC758 (Benisty+, 2015)
J/A+A/611/A74 : Angular differential imaging of MCW 758 (Reggiani+, 2018)
Byte-by-byte Description of file: fits.dat
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Bytes Format Units Label Explanations
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1- 8 F8.5 deg RAdeg Right ascension of center (J2000)
9- 17 F9.5 deg DEdeg Declination of center (J2000)
19- 22 I4 --- Nx [4500] Number of pixels along X-axis (NAXIS1)
23 A1 --- --- [x]
24- 27 I4 --- Ny [4500] Number of pixels along Y-axis (NAXIS2)
29- 54 A26 --- Date UTC observation date
56- 66 E11.6 Hz Freq [3.43493e+11/3.43493e+11] Frequence
68- 72 I5 Kibyte Size Size of the FITS file
74- 95 A22 --- FileName Name of the file in subdirectory fits (1)
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Note (1): The version of the image synthesized using the natural weighting
scheme is not shown in the paper.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 05-Jul-2019