YSO Jets in the Galactic Plane from UWISH2. IV. Jets and Outflows in Cygnus-X
Abstract
We have performed an unbiased search for outflows from young stars in Cygnus-X using 42 deg2 of data from the UKIRT Widefield Infrared Survey for H2 (UWISH2 Survey), to identify shock-excited near-IR H2 emission in the 1-0 S(1) 2.122 μm line. We uncovered 572 outflows, of which 465 are new discoveries, increasing the number of known objects by more than 430%. This large and unbiased sample allows us to statistically determine the typical properties of outflows from young stars. We found 261 bipolar outflows, and 16% of these are parsec scale. The typical bipolar outflow is 0.45 pc in length and has gaps of 0.025-0.1 pc between large knots. The median luminosity in the 1-0 S(1) line is 10-3 {L}⊙ . The bipolar flows are typically asymmetrical, with the two lobes misaligned by 5°, one lobe 30% shorter than the other, and one lobe twice as bright as the other. Of the remaining outflows, 152 are single-sided and 159 are groups of extended, shock-excited H2 emission without identifiable driving sources. Half of all driving sources have sufficient WISE data to determine their evolutionary status as either protostars (80%) or classical T Tauri stars (20%). One-fifth of the driving sources are variable by more than 0.5 mag in the K-band continuum over several years. Several of the newly identified outflows provide excellent targets for follow-up studies. We particularly encourage the study of the outflows and young stars identified in a bright-rimmed cloud near IRAS 20294+4255, which seems to represent a textbook example of triggered star formation.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- January 2018
- DOI:
- 10.3847/1538-4365/aa8862
- arXiv:
- arXiv:1708.00394
- Bibcode:
- 2018ApJS..234....8M
- Keywords:
-
- catalogs;
- ISM: jets and outflows;
- stars: formation;
- stars: protostars;
- stars: winds;
- outflows;
- surveys;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 27 pages, 10 figures, accepted for publication in ApJS. Appendix contains examples from the two image sets and machine-readable data table that will be available in the online journal. Full version available at http://astro.kent.ac.uk/~df/papers.html with full appendix