How Do Stars Gain Their Mass? A JCMT/SCUBA-2 Transient Survey of Protostars in Nearby Star-forming Regions

Gregory J. Herczeg, Doug Johnstone, Steve Mairs, Jennifer Hatchell, Jeong-Eun Lee, Geoffrey C. Bower, Huei-Ru Vivien Chen, Yuri Aikawa, Hyunju Yoo, Sung-Ju Kang, Miju Kang, Wen-Ping Chen, Jonathan P. Williams, Jaehan Bae, Michael M. Dunham, Eduard I. Vorobyov, Zhaohuan Zhu, Ramprasad Rao, Helen Kirk, Satoko TakahashiOscar Morata, Kevin Lacaille, James Lane, Andy Pon, Aleks Scholz, Manash R. Samal, Graham S. Bell, Sarah Graves, E'lisa M. Lee, Harriet Parsons, Yuxin He, Jianjun Zhou, Mi-Ryang Kim, Scott Chapman, Emily Drabek-Maunder, Eun Jung Chung, Stewart P. S. Eyres, Jan Forbrich, Lynne A. Hillenbrand, Shu-ichiro Inutsuka, Gwanjeong Kim, Kyoung Hee Kim, Yi-Jehng Kuan, Woojin Kwon, Shih-Ping Lai, Bhavana Lalchand, Chang Won Lee, Chin-Fei Lee, Feng Long, A-Ran Lyo, Lei Qian, Peter Scicluna, Archana Soam, Dimitris Stamatellos, Shigehisa Takakuwa, Ya-Wen Tang, Hongchi Wang, Yiren Wang

Veröffentlichungen: Beitrag in FachzeitschriftArtikelPeer Reviewed


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 James Clerk Maxwell Telescope/SCUBA-2 Transient Survey of Protostars in Nearby Star-forming Regions, we are monitoring monthly with SCUBA-2 the submillimeter emission in eight fields within nearby (<500 pc) star-forming regions to measure the accretion variability of protostars. The total survey area of ∼1.6 deg 2 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 submillimeter observations to reach a precision of ∼2%-3% rms, and also provides quantified confidence in any measured variability. The timescales and amplitudes of any submillimeter 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 submillimeter variability and complements other transient surveys at optical and near-IR wavelengths, which are not sensitive to accretion variability of deeply embedded protostars.

FachzeitschriftThe Astrophysical Journal
PublikationsstatusVeröffentlicht - Nov. 2017

ÖFOS 2012

  • 103003 Astronomie
  • 103004 Astrophysik