Issue |
A&A
Volume 689, September 2024
|
|
---|---|---|
Article Number | A104 | |
Number of page(s) | 12 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361/202450278 | |
Published online | 06 September 2024 |
From traffic jams to roadblocks: The outer regions of TW Hya with ALMA Band 8
1
Max Planck Institute for Astronomy,
Königstuhl 17,
69117
Heidelberg,
Germany
e-mail: das@mpia.de
2
Department of Physics, Sardar Vallabhbhai National Institute of Technology,
Dumas Road,
395007
Surat,
India
3
Max Planck Institute for Extraterrestrial Physics,
Giebenbachstrabe 1,
85748
Garching,
Germany
Received:
7
April
2024
Accepted:
3
July
2024
Context. Current ALMA surveys often underestimate protoplanetary disk sizes as many disks have extended low surface-brightness regions that fall below ALMA’s detection limits. To effectively capture faint millimeter continuum emission in these outer regions, increased sensitivity is required.
Aims. In order to gain insights on the connection between disk structure and planet formation, we aim to uncover continuum emission in the outer regions of the disk around TW Hya. Additionally, we aim to investigate the evolution of this disk by studying its dust properties.
Methods. We present Atacama Large Millimeter Array (ALMA) observations of TW Hya at 0.65 mm with ~0.5 arcsecond angular resolution, together with high angular resolution archival observations at 0.87,1.3, 2.1 and 3.1 mm. We constrain the outer disk emission with both image-plane retrieval, and visibility-plane modeling with non-parametric and parametric fitting tools.
Results. Our results confirm emission in the outer disk regions of TW Hya (60 au ≤ R ≤ 110 au) at 0.65, 0.87 and 1.3 mm. With image-plane retrieval, we resolve the new continuum gap and ring, namely D79 and B86, at 0.87 and 1.3 mm. With visibility-plane modeling, we also detect this substructure at 0.65 mm in the form of a quasi-constant emission at the 1σ level. Furthermore, it has a high spectral index of 3.7, which may indicate dust grain sizes <<1 mm. It may be a dust trap or a traffic jam, that has a flux density of ~60 mJy and a mass (1.59 M⊕) that accounts for up to 2% of the dust disk at 0.65 mm.
Conclusions. We confirm the existence of a faint ring in the outer regions of TW Hya at multiple millimeter wavelengths. With visibility-plane modeling, we are able to set constrains that are 3 times better than the resolution of our Band 8 observations.
Key words: methods: observational / techniques: interferometric / planets and satellites: formation / protoplanetary disks / stars: low-mass / radio continuum: planetary systems
© The Authors 2024
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This article is published in open access under the Subscribe to Open model.
Open Access funding provided by Max Planck Society.
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