J/A+A/685/A18 DM Tau JVLA image (Liu+, 2024)
Forming localized dust concentrations in a dust ring? DM Tau case study.
The asymmetric 7 mm dust continuum of the DM Tau disk.
Liu H.B., Muto T., Konishi M., Chung C.-Y., Hashimoto J., Doi K., Dong R.,
Kudo T., Hasegawa Y., Terada Y., Kataoka A.
<Astron. Astrophys. 685, A18 (2024)>
=2024A&A...685A..18L 2024A&A...685A..18L (SIMBAD/NED BibCode)
ADC_Keywords: Protostars ; Radio sources
Keywords: planets and satellites: formation - protoplanetary disks -
dust, extinction - ISM: individual objects: DM Tau
Abstract:
Previous high-angular-resolution 225GHz (∼1.3mm) continuum
observations of the transitional disk DM Tau have resolved
an outer ring at 20-120au radii that is weakly azimuthally asymmetric.
We aim to examine dust growth and filtration in the outer ring of
DM Tau.
We performed the ∼0.06" (∼8.7au) resolution Karl G. Jansky Very Large
Array (JVLA) 40-48GHz (∼7mm; Q band) continuum observations and the
complementary observations at lower frequencies. In addition, we
analyzed the archival JVLA observations that were taken since 2010.
Intriguingly, the Q band image resolved the azimuthally highly
asymmetric, knotty dust emission sources close to the inner edge of
the outer ring. Fitting the 8-700GHz spectral energy distribution
(SED) with two dust components indicates that the maximum grain size
(amax) in these knotty dust emission sources is likely ≳300um while
it is ≲50um in the rest of the ring. These results may be explained
by trapping of inward migrating grown dust close to the ring inner
edge.The exact mechanism for developing the azimuthal asymmetry has
not yet been identified, which may be due to planet-disk interaction
that might also be responsible for the creation of the dust cavity and
pressure bump, or the fluid instabilities and vortex formation due to
shear motions.
Finally, we remark that the asymmetries in DM Tau are difficult to
diagnose from the ≳225GHz observations, owing to a high optical depth
at the ring. In other words, the apparent symmetric or asymmetric
morphology of the transitional disks may be related to the optical
depths of those disks at the observing frequency
Description:
We carried out the JVLA observations towards DM Tau at Q (40-48GHz),
Ku (12-18GHz), and X (8-12GHz) bands in 2019.
We provide the JVLA image used in Figure 2 in FITS format.
Objects:
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RA (2000) DE Designation(s)
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04 33 48.73 +18 10 09.9 DM Tau = 2MASS J04334871+1810099
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 85 1 Informations 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- 50 A21 "datime" Obs.date Observation date
52- 56 I5 Kibyte size Size of FITS file
58- 67 A10 --- FileName Name of FITS file, in subdirectory fits
69- 85 A17 --- Title Title of the FITS file
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Acknowledgements:
Hauyu Baobab Liu, baobabyoo(at)gmail.com
(End) Patricia Vannier [CDS] 19-Feb-2024