ALMA Resolves C i Emission from the β Pictoris Debris Disk
Artikel i vetenskaplig tidskrift, 2018
The debris disk around β Pictoris is known to contain gas. Previous ALMA observations revealed a CO belt at ∼85 au with a distinct clump, interpreted as a location of enhanced gas production. Photodissociation converts CO into C and O within ∼50 a. We resolve C i emission at 492 GHz using ALMA and study its spatial distribution. C i shows the same clump as seen for CO. This is surprising, as C is expected to quickly spread in azimuth. We derive a low C mass (between 5 ×10-4and 3.1 ×10-3), indicating that gas production started only recently (within ∼5000 a). No evidence is seen for an atomic accretion disk inward of the CO belt, perhaps because the gas did not yet have time to spread radially. The fact that C and CO share the same asymmetry argues against a previously proposed scenario where the clump is due to an outward-migrating planet trapping planetesimals in a resonance, nor can the observations be explained by an eccentric planetesimal belt secularly forced by a planet. Instead, we suggest that the dust and gas disks should be eccentric. Such a configuration, we further speculate, might be produced by a recent tidal disruption event. Assuming that the disrupted body has had a CO mass fraction of 10%, its total mass would be 3 MMoon.
stars: individual (beta Pictoris)
radiative transfer
techniques: interferometric
methods: observational
circumstellar matter
submillimeter: planetary systems
Författare
Gianni Cataldi
Magyar Tudomanyos Akademia
National Astronomical Observatory of Japan
Stockholms universitet
Alba Nova Universitetscentrum
A. Brandeker
Alba Nova Universitetscentrum
Stockholms universitet
Y. Wu
University of Toronto
C. H. Chen
Space Telescope Science Institute (STScI)
Johns Hopkins University
W. R. F. Dent
European Southern Observatory Santiago
B. L. D. Vries
Alba Nova Universitetscentrum
European Space Research and Technology Centre (ESA ESTEC)
Stockholms universitet
I. Kamp
Rijksuniversiteit Groningen
René Liseau
Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium
G. Olofsson
Alba Nova Universitetscentrum
Stockholms universitet
E. Pantin
Centre national de la recherche scientifique (CNRS)
A. Roberge
National Aeronautics and Space Administration (NASA)
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 861 1 72Ämneskategorier (SSIF 2011)
Subatomär fysik
Astronomi, astrofysik och kosmologi
DOI
10.3847/1538-4357/aac5f3