2024-03-29T08:06:30Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:00025081
2023-01-16T04:15:48Z
336:695:696
Faint warm debris disks around nearby bright stars explored by AKARI and IRSF
Ishihara, Daisuke
74793
Takeuchi, Nami
74794
Kobayashi, Hiroshi
74795
Nagayama, Takahiro
74796
Kaneda, Hidehiro
74797
Inutsuka, Shu-ichiro
74798
Fujiwara, Hideaki
74799
Onaka, Takashi
74800
circumstellar matter
zodiacal dust
infrared: stars
Context. Debris disks are important observational clues for understanding planetary-system formation process. In particular, faint warm debris disks may be related to late planet formation near 1 au. A systematic search of faint warm debris disks is necessary to reveal terrestrial planet formation. Aims. Faint warm debris disks show excess emission that peaks at mid-IR wavelengths. Thus we explore debris disks using the AKARI mid-IR all-sky point source catalog (PSC), a product of the second generation unbiased IR all-sky survey. Methods. We investigate IR excess emission for 678 isolated main-sequence stars for which there are 18 m detections in the AKARI mid-IR all-sky catalog by comparing their fluxes with the predicted fluxes of the photospheres based on optical to near-IR fluxes and model spectra. The near-IR fluxes are first taken from the 2MASS PSC. However, 286 stars with Ks < 4:5 in our sample have large flux errors in the 2MASS photometry due to saturation. Thus we have measured accurate J, H, and Ks band fluxes, applying neutral density (ND) filters for Simultaneous InfraRed Imager for Unbiased Survey (SIRIUS) on IRSF, the 1.4m near-IR telescope in South Africa, and improved the flux accuracy from 14% to 1.8% on average. Results. We identified 53 debris-disk candidates including eight new detections from our sample of 678 main-sequence stars. The detection rate of debris disks for this work is 8%, which is comparable with those in previous works by Spitzer and Herschel. Conclusions. The importance of this study is the detection of faint warm debris disks around nearby field stars. At least nine objects have a large amount of dust for their ages, which cannot be explained by the conventional steady-state collisional cascade model.
journal article
EDP Sciences
2017-05
application/pdf
ASTRONOMY & ASTROPHYSICS
601
A72
A72
http://doi.org/10.1051/0004-6361/201526215
http://hdl.handle.net/2237/27302
0004-6361
https://nagoya.repo.nii.ac.jp/record/25081/files/aa26215-15.pdf
eng
https://doi.org/10.1051/0004-6361/201526215