Oral Presentation

Keplerian Disk, its Internal Structure and Evolutionary Status around a Low-Luminosity Stellar Object J162656.43-243301.5

Author(s): Shigehisa Takakuwa (Kagoshima University), Ryohei Kawabe (NAOJ), Yoshito Shimajiri (Kyushu Kyoritsu University), Takashi Tsukagoshi (Ashikaga University), Yusuke Aso (KASI), Jinshi Sai (ASIAA)

Presenter: Shigehisa Takakuwa (Kagoshima University)

We report our recent ALMA observations of a low-luminosity stellar object J162656.43-243301.5 at Band 6. Our highest-resolution and sensitive ALMA observations have unveiled a possible spiral-arm feature in the dust disk, whose mass is as low as one earth mass. The 12CO, 13CO, and C18O (2-1) lines show signatures of Keplerian rotation. Our Keplerian disk model fitting nicely reproduces the observed velocity channel maps of all the CO isotopologue emission with a central stellar mass of ~0.35 Msun and a disk radius of ~30 au. We will discuss the evolutionary stage of this low-luminosity object and the Keplerian disk in conjunction with radiative transfer modeling.