How do stars gain their mass? A JCMT/SCUBA-2 Transient Survey of Protostars in Nearby Star Forming Regions
Creators: name: Herczeg, Gregory J.
name: Johnstone, Doug
name: Mairs, Steve
name: Hatchell, Jennifer
name: Lee, Jeong-Eun
name: Bower, Geoffrey C.
name: Chen, Huei-Ru Vivien
name: Aikawa, Yuri
name: Yoo, Hyunju
name: Kang, Sung-Ju
name: Kang, Miju
name: Chen, Wen-Ping
name: Williams, Jonathan P.
name: Bae, Jaehan
name: Dunham, Michael M.
name: Vorobiov, Eduard I.
name: Zhu, Zhaohuan
name: Rao, Ramprasad
name: Kirk, Helen
name: Takahashi, Satoko
name: Morata, Oscar
name: Lacaille, Kevin
name: Lane, James
name: Pon, Andy
name: Scholz, Aleks
name: Samal, Manash R.
name: Bell, Graham S.
name: Graves, Sarah
name: Lee, E'lisa M.
name: Parsons, Harriet
name: He, Yuxin
name: Zhou, Jianjun
name: Kim, Mi-Ryang
name: Chapman, Scott
name: Drabek-Maunder, Emily
name: Chung, Eun Jung
name: Eyres, Stewart P. S.
name: Forbrich, Jan
name: Hillenbrand, Lynne A.
name: Inutsuka, Shu-ichiro
name: Kim, Gwanjeong
name: Kim, Kyoung Hee
name: Kuan, Yi-Jehng
name: Kwon, Woojin
name: Lai, Shih-Ping
name: Lalchand, Bhavana
name: Lee, Chang Won
name: Lee, Chin-Fei
name: Long, Feng
name: Lyo, A-Ran
name: Qian, Lei
name: Scicluna, Peter
name: Soam, Archana
name: Stamatellos, Dimitris
name: Takakuwa, Shigehisa
name: Tang, Ya-Wen
name: Wang, Hongchi
name: Wang, Yiren
Publisher: name: arXiv
Year: 2017
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Most protostars have luminosities that are fainter than expected from steady accretion over the protostellar lifetime. The solution to this problem may lie in episodic mass accretion -- prolonged periods of very low accretion punctuated by short bursts of rapid accretion. However, the timescale and amplitude for variability at the protostellar phase is almost entirely unconstrained. In "A JCMT/SCUBA-2 Transient Survey of Protostars in Nearby Star Forming Regions", we are monitoring monthly with SCUBA-2 the sub-mm emission in eight fields within nearby (&lt;500 pc) star forming regions to measure the accretion variability of protostars. The total survey area of ~1.6 sq.deg. includes ~105 peaks with peaks brighter than 0.5 Jy/beam (43 associated with embedded protostars or disks) and 237 peaks of 0.125-0.5 Jy/beam (50 with embedded protostars or disks). Each field has enough bright peaks for flux calibration relative to other peaks in the same field, which improves upon the nominal flux calibration uncertainties of sub-mm observations to reach a precision of ~2-3% rms, and also provides quantified confidence in any measured variability. The timescales and amplitudes of any sub-mm variation will then be converted into variations in accretion rate and subsequently used to infer the physical causes of the variability. This survey is the first dedicated survey for sub-mm variability and complements other transient surveys at optical and near-IR wavelengths, which are not sensitive to accretion variability of deeply embedded protostars.
description: ApJ, accepted