JpGU-AGU Joint Meeting 2017

Presentation information

[EJ] Poster

P (Space and Planetary Sciences) » P-PS Planetary Sciences

[P-PS04] [EJ] New developments of planetary sciences with ALMA

Wed. May 24, 2017 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall HALL7)

[PPS04-P09] Detection of submillimeter-wave [C I] emission in gaseous debris disks; 49 Ceti and β Pictoris

*Aya Higuchi1, Sato Aki2, Takashi Tsukagoshi2, Nami Sakai1, Munetake Momose2, Hiroshi Kobayashi3, Daisuke Ishihara3, Sakae Watanabe3, Hidehiro Kaneda3, Kazunari Iwasaki4, Satoshi Yamamoto5 (1.RIKEN, 2.Ibaraki University, 3.Nagoya University, 4.Doshisha University, 5.The University of Tokyo)

Keywords:debris disk

We have detected the [C I]3P13P0 emission in the gaseous debris disks, 49 Ceti and β Pictoris, with the Atacama Submillimeter Telescope Experiment (ASTE). The line profiles of [C I] is found to be those of CO(J=3–2) observed with the same telescope as well as the Atacama Large Millimeter/submillimeter Array (ALMA). This result suggests that the atomic carbon (C) coexists with CO in the debris disks, and is likely formed by photodissociation of CO. The C/CO column density ratio is thus derived to be 54±19 to 69±42 for 49 Ceti and β Pictoris, respectively. These ratios are higher than those of protoplanetary disks, molecular clouds, and diffuse clouds by an order of magnitude. From the result, we suggest that the origin of a large amount of [C I] in the debris disk would likely be a small amount of the H2 molecule in the gas disk. This implies a significant contribution of the secondary gas coming out from dust grains.