Resolving the Polarized Dust Emission of the Disk around the Massive Star Powering the HH 80-81 Radio Jet

Here we present deep (16 μJy beam-1), very high (40 mas) angular resolution 1.14 mm, polarimetric, Atacama Large Millimeter/submillimeter Array (ALMA) observations toward the massive protostar driving the HH 80-81 radio jet. The observations clearly resolve the disk oriented perpendicularly to the r...

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Detalhes bibliográficos
Autores: Girart, J. M., Fernandez Lopez, Manuel, Li, Z. Y., Yang, H., Estalella, R., Anglada, G., Anez López, N., Busquet, G., Carrasco González, C., Curiel, S., Galvan Madrid, R., Gómez, J. F., Gregorio Monsalvo, I. De, Jiménez Serra, I., Krasnopolsky, R., Marti, J., Osorio, M., Padovani, M., Rao, R., Rodriguez, L. F., Torrelles, J. M.
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2018
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/82405
Acesso em linha:http://hdl.handle.net/11336/82405
Access Level:acceso abierto
Palavra-chave:ACCRETION
ACCRETION DISKS-ISM: INDIVIDUAL OBJECTS (GGD27
HH 80-81
IRAS 18162-2048)-STARS: FORMATION
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descrição
Resumo:Here we present deep (16 μJy beam-1), very high (40 mas) angular resolution 1.14 mm, polarimetric, Atacama Large Millimeter/submillimeter Array (ALMA) observations toward the massive protostar driving the HH 80-81 radio jet. The observations clearly resolve the disk oriented perpendicularly to the radio jet, with a radius of ≃0.″171 (∼291 au at 1.7 kpc distance). The continuum brightness temperature, the intensity profile, and the polarization properties clearly indicate that the disk is optically thick for a radius of R ≲ 170 au. The linear polarization of the dust emission is detected almost all along the disk, and its properties suggest that dust polarization is produced mainly by self-scattering. However, the polarization pattern presents a clear differentiation between the inner (optically thick) part of the disk and the outer (optically thin) region of the disk, with a sharp transition that occurs at a radius of ∼0.″1 (∼170 au). The polarization characteristics of the inner disk suggest that dust settling has not occurred yet with a maximum dust grain size between 50 and 500 μm. The outer part of the disk has a clear azimuthal pattern but with a significantly higher polarization fraction compared to the inner disk. This pattern is broadly consistent with the self-scattering of a radiation field that is beamed radially outward, as expected in the optically thin outer region, although contribution from non-spherical grains aligned with respect to the radiative flux cannot be excluded.

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