The radial extent of millimetre dust in protoplanetary discs is often far smaller than that of their gas, mostly due to processes such as dust growth and radial drift. However, it has been suggested that current millimetre continuum observations of discs do not trace their full extent due to limited sensitivity. In this letter, we present deep (19 $\mu$Jy beam-1) moderate resolution (0.37 arcsec) ALMA observations at 1 mm of the nearest protoplanetary disc, TW Hya. Using the visibility analysis tool frank, we reveal a structured millimetre intensity distribution out to 100 au, well beyond previous estimates of 60-70 au. Our analysis suggests the presence of a new millimetre continuum gap at 82 au, coincident with similar features seen in optical/near-infrared scattered light and millimetre molecular line observations. Examination of the fit residuals confirms the presence of the previously reported au-scale continuum excess at 52 au (P.A. = 242.5°). Our results demonstrate the utility of combining deep, moderate-resolution observations with super-resolution analysis techniques to probe the faintest regions of protoplanetary discs.
Unveiling the outer dust disc of TW Hya with deep ALMA observations / J. D Ilee, C. Walsh, J. Jennings, R. A Booth, G.P. Rosotti, R. Teague, T. Tsukagoshi, H. Nomura. - In: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY. LETTERS. - ISSN 1745-3933. - 515:1(2022 Sep), pp. L23-L28. [10.1093/mnrasl/slac048]
Unveiling the outer dust disc of TW Hya with deep ALMA observations
G.P. Rosotti;
2022
Abstract
The radial extent of millimetre dust in protoplanetary discs is often far smaller than that of their gas, mostly due to processes such as dust growth and radial drift. However, it has been suggested that current millimetre continuum observations of discs do not trace their full extent due to limited sensitivity. In this letter, we present deep (19 $\mu$Jy beam-1) moderate resolution (0.37 arcsec) ALMA observations at 1 mm of the nearest protoplanetary disc, TW Hya. Using the visibility analysis tool frank, we reveal a structured millimetre intensity distribution out to 100 au, well beyond previous estimates of 60-70 au. Our analysis suggests the presence of a new millimetre continuum gap at 82 au, coincident with similar features seen in optical/near-infrared scattered light and millimetre molecular line observations. Examination of the fit residuals confirms the presence of the previously reported au-scale continuum excess at 52 au (P.A. = 242.5°). Our results demonstrate the utility of combining deep, moderate-resolution observations with super-resolution analysis techniques to probe the faintest regions of protoplanetary discs.File | Dimensione | Formato | |
---|---|---|---|
slac048(2).pdf
accesso riservato
Tipologia:
Publisher's version/PDF
Dimensione
1.46 MB
Formato
Adobe PDF
|
1.46 MB | Adobe PDF | Visualizza/Apri Richiedi una copia |
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.