The JCMT Transient Survey: Identifying Submillimeter Continuum Variability over Several Year Timescales Using Archival JCMT Gould Belt Survey Observations

Steve Mairs, Doug Johnstone, Helen Kirk, James Lane, Graham S. Bell, Sarah Graves, Gregory J. Herczeg, Peter Scicluna, Geoffrey C. Bower, Huei Ru Vivien Chen, Jennifer Hatchell, Yuri Aikawa, Wen Ping Chen, Miju Kang, Sung Ju Kang, Jeong Eun Lee, Oscar Morata, Andy Pon, Aleks Scholz, Satoko TakahashiHyunju Yoo

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

Investigating variability at the earliest stages of low-mass star formation is fundamental in understanding how a protostar assembles mass. While many simulations of protostellar disks predict non-steady accretion onto protostars, deeper investigation requires robust observational constraints on the frequency and amplitude of variability events characterized across the observable SED. In this study, we develop methods to robustly analyze repeated observations of an area of the sky for submillimeter variability in order to determine constraints on the magnitude and frequency of deeply embedded protostars. We compare 850 μm JCMT Transient Survey data with archival JCMT Gould Belt Survey data to investigate variability over 2-4 year timescales. Out of 175 bright, independent emission sources identified in the overlapping fields, we find seven variable candidates, five of which we classify as Strong, and the remaining two we classify as Extended to indicate that the latter are associated with larger-scale structure. For the Strong variable candidates, we find an average fractional peak brightness change per year of |4.0|% yr-1, with a standard deviation of 2.7% yr-1. In total, 7% of the protostars associated with 850 μm emission in our sample show signs of variability. Four of the five Strong sources are associated with a known protostar. The remaining source is a good follow-up target for an object that is anticipated to contain an enshrouded, deeply embedded protostar. In addition, we estimate the 850 μm periodicity of the submillimeter variable source, EC 53, to be 567 ±32 days, based on the archival Gould Belt Survey data.

Original languageEnglish
Article number107
JournalAstrophysical Journal
Volume849
Issue number2
DOIs
StatePublished - 10 Nov 2017

Keywords

  • ISM: structure
  • catalogs
  • stars: formation
  • stars: pre-main sequence
  • submillimeter: ISM
  • submillimeter: general

Fingerprint

Dive into the research topics of 'The JCMT Transient Survey: Identifying Submillimeter Continuum Variability over Several Year Timescales Using Archival JCMT Gould Belt Survey Observations'. Together they form a unique fingerprint.

Cite this