We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of the CO (J=2--1) line emission from the protoplanetary disk around T-Tauri star SU Aurigae (hereafter SU Aur). Previous observations in optical and near infrared wavelengths find a unique structure in SU Aur. One of the highlights of the observational results is that an extended tail-like structure is associated with the disk, indicating mass transfer from or into the disk. Here we report the discovery of the counterpart of the tail-like structure in CO gas extending more than 1000 au long. Based on geometric and kinematic perspectives, both of the disk and the tail-like structure components physically connect to each other. Several theoretical studies predicted the observed tail-like structure via the following possible scenarios, 1) a gaseous stream from the molecular cloud remnant, 2) collision with a (sub)stellar intruder or a gaseous blob from the ambient cloud, and 3) ejection of a planetary or brown dwarf mass object due to gravitational instability via multi-body gravitational interaction. Since the tail-like structures associated with the SU Aur disk is a new example following RW Aurigae, some disks may experience the internal or external interaction and drastically lose mass during disk evolution.
@article{arxiv.1902.10306,
title = {A Tail Structure Associated with Protoplanetary Disk around SU Aurigae},
author = {Eiji Akiyama and Eduard I. Vorobyov and Hauyu Baobabu Liu and Ruobing Dong and Jerome de Leon and Sheng-Yuan Liu and Motohide Tamura},
journal= {arXiv preprint arXiv:1902.10306},
year = {2019}
}