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

methods: observational

submillimeter: planetary systems

circumstellar matter

techniques: interferometric

Författare

Gianni Cataldi

Stockholms universitet

National Astronomical Observatory of Japan

Magyar Tudomanyos Akademia

AlbaNova University Center

A. Brandeker

Stockholms universitet

AlbaNova University Center

Y. Wu

University of Toronto

C. H. Chen

Johns Hopkins University

Space Telescope Science Institute (STScI)

W. R. F. Dent

European Southern Observatory Santiago

B. L. D. Vries

AlbaNova University Center

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

AlbaNova University Center

Stockholms universitet

E. Pantin

Centre national de la recherche scientifique (CNRS)

A. Roberge

NASA Goddard Space Flight Center

Astrophysical Journal

0004-637X (ISSN) 1538-4357 (eISSN)

Vol. 861 1 72

Ämneskategorier

Subatomär fysik

Astronomi, astrofysik och kosmologi

DOI

10.3847/1538-4357/aac5f3

Mer information

Senast uppdaterat

2019-09-10