The ALMA view of W33A: A Spiral Filament Feeding the Candidate Disc in MM1-Main
- Resource Type
- Authors
- Roberto Galván-Madrid; Qizhou Zhang; Eric Keto; W. J. de Wit; Jaime E. Pineda; Katharine G. Johnston; Melvin Hoare; Luke T. Maud
- Source
- MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (ISSN 0035-8711), 467, L120-L124
Scopus-Elsevier
- Subject
- Physics
010308 nuclear & particles physics
Young stellar object
Compact disc
FOS: Physical sciences
Binary number
Astronomy
Centroid
Astronomy and Astrophysics
Kinematics
Astrophysics
01 natural sciences
Astrophysics - Astrophysics of Galaxies
Protein filament
Astrophysics - Solar and Stellar Astrophysics
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
0103 physical sciences
Millimeter
Emission spectrum
010303 astronomy & astrophysics
Solar and Stellar Astrophysics (astro-ph.SR)
- Language
- English
- ISSN
- 1745-3925
We targeted the massive star forming region W33A using the Atacama Large Sub/Millimeter Array (ALMA) in band 6 (230 GHz) and 7 (345 GHz) to search for a sub-1000au disc around the central O-type massive young stellar object (MYSO) W33A MM1-Main. Our data achieves a resolution of ~0.2" (~500au) and resolves the central core, MM1, into multiple components and reveals complex and filamentary structures. There is strong molecular line emission covering the entire MM1 region. The kinematic signatures are inconsistent with only Keplerian rotation although we propose that the shift in the emission line centroids within ~1000au of MM1-Main could hint at an underlying compact disc with Keplerian rotation. We cannot however rule out the possibility of an unresolved binary or multiple system. A putative smaller disc could be fed by the large scale spiral `feeding filament' we detect in both gas and dust emission. We also discuss the nature of the now-resolved continuum sources.