J/A+A/673/A77 ALMA view of MP Mus (PDS 66) (Ribas+, 2023)
The ALMA view of MP Mus (PDS 66):
A protoplanetary disk with no visible gaps down to 4 au scales.
Ribas A., Macias E., Weber P., Perez S., Cuello N., Dong R., Aguayo A.,
Caceres C., Carpenter J., Dent W.R.F., de Gregorio-Monsalvo I., Duchene G.,
Espaillat C.C., Riviere-Marichalar P., Villenave M.
<Astron. Astrophys. 673, A77 (2023)>
=2023A&A...673A..77R 2023A&A...673A..77R (SIMBAD/NED BibCode)
ADC_Keywords: Stars, pre-main sequence ; Radio continuum ; Radio lines
Keywords: accretion, accretion disks - protoplanetary disks -
protoplanetary disks - planets and satellites: formation -
stars: individual: MP Mus - stars: pre-main sequence -
techniques: interferometric
Abstract:
We present ALMA multiwavelength observations of the protoplanetary
disk around the nearby (d∼100pc) young solar analog MP Mus (PDS 66).
These observations at 0.89mm, 1.3mm, and 2.2mm have angular
resolutions of ∼1", 0.05", and 0.25", respectively, and probe the dust
and gas in the system with unprecedented detail and sensitivity. The
disk appears smooth down to the 4au resolution of the 1.3mm
observations, in contrast with most disks observed at comparable
spatial scales. The dust disk has a radius of 60au, a dust mass of
0.14MJup, and a mm spectral index <2 in the inner 30au, suggesting
optically thick emission from grains with high albedo in this region.
Several molecular gas lines are also detected extending up to 130au,
similar to small grains traced by scattered light observations.
Comparing the fluxes of different CO isotopologues with previous
models yields a gas mass of 0.1-1MJup, implying a gas to dust ratio
of 1-10. We also measure a dynamical stellar mass of
Mdyn=1.30M☉ and derive an age of 7-10Myr for the system. The
survival of large grains in an evolved disk without gaps/rings is
surprising, and it is possible that existing substructures remain
undetected due to optically thick emission at 1.3mm. Alternatively,
small structures may still remain unresolved with the current
observations. Based on simple scaling relations for gap-opening
planets and gap widths, this lack of substructures places upper limits
to the masses of planets in the disk as low as 2M⊕-0.06MJup
at r>40au. The lack of mm emission at radii r>60au also suggests that
the gap in scattered light between 30-80au is likely not a gap in the
disk density, but a shadow cast by a puffed-up inner disk.
Description:
We present images of the dust continuum emission at 0.87mm (Band 7),
1.3mm (Band 6), and 2.2mm (Band4), as well as cubes for multiple
molecular gas lines of the protoplanetary disk around MP Mus, obtained
with the Atacama Large Millimeter/submillimeter Array. The continuum
images are provided with two different Briggs weighting: using a
robust parameter 0 as a compromise between angular resolution and
sensitivity, and with a robust value of t -0.5 value that produces a
higher angular resolution. For the line cubes, we used Natural or
Briggs weighting depending on the S/N of each case, as indicated in
the file names. All images are presented as FITS files.
Objects:
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RA (2000) DE Designation(s)
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13 22 07.54 -69 38 12.2 MP Mus = PDS 66
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 171 16 List of fits images and datacubes
fits/* . 16 Individual fits images and datacubes
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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- 30 I3 --- Nz ? Number of slices for the datacubes
32- 57 A26 "datime" Obs.date Observation date
59- 65 F7.3 GHz Freq Observed frequency or lower value of
observed frequencies for the datacubes
67- 73 F7.3 GHz BFreq ? Upper value of observed frequencies
for the datacubes
75- 80 I6 Hz dFreq ? Frequency resolution for the datacubes
82- 87 I6 Kibyte size Size of FITS file
89-117 A29 --- FileName Name of FITS file, in subdirectory fits
119-171 A53 --- Title Title of the FITS file
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Acknowledgements:
Alvaro Ribas, aribas.astro(at)gmail.com
(End) Patricia Vannier [CDS] 06-Mar-2023