000005090 001__ 5090
000005090 005__ 20210104165808.0
000005090 0247_ $$2DOI$$a10.1051/0004-6361/201731379
000005090 037__ $$aSCART-2021-0003
000005090 100__ $$aMorford, J. C.
000005090 245__ $$aCOBRaS: The e-MERLIN 21 cm Legacy survey of Cygnus OB2
000005090 260__ $$c2020
000005090 520__ $$aContext. The role of massive stars is central to an understanding of galactic ecology. It is important to establish the details of how massive stars provide radiative, chemical, and mechanical feedback in galaxies. Central to these issues is an understanding of the evolution of massive stars, and the critical role of mass loss via strongly structured winds and stellar binarity. Ultimately, and acting collectively, massive stellar clusters shape the structure and energetics of galaxies. Aims: We aim to conduct high-resolution, deep field mapping at 21 cm of the core of the massive Cygnus OB2 association and to characterise the properties of the massive stars and colliding winds at this waveband. Methods: We used seven stations of the e-MERLIN radio facility, with its upgraded bandwidth and enhanced sensitivity to conduct a 21 cm census of Cygnus OB2. Based on 42 hours of observations, seven overlapping pointings were employed over multiple epochs during 2014 resulting in 1σ sensitivities down to ∼21 μJy and a resolution of ∼180 mas. Results: A total of 61 sources are detected at 21 cm over a ∼0.48° × 0.48° region centred on the heart of the Cyg OB2 association. Of these 61 sources, 33 are detected for the first time. We detect a number of previously identified sources including four massive stellar binary systems, two YSOs, and several known X-ray and radio sources. We also detect the LBV candidate (possible binary system) and blue hypergiant star of Cyg OB2 #12. Conclusions: The 21 cm observations secured in the COBRaS Legacy project provide data to constrain conditions in the outer wind regions of massive stars; determine the non-thermal properties of massive interacting binaries; examine evidence for transient sources, including those associated with young stellar objects; and provide unidentified sources that merit follow-up observations. The 21 cm data are of lasting value and will serve in combination with other key surveys of Cyg OB2, including Chandra and Spitzer. 
000005090 594__ $$aNO
000005090 6531_ $$aopen clusters and associations: individual: Cygnus OB2
000005090 6531_ $$aradio continuum: stars
000005090 6531_ $$atechniques: interferometric
000005090 6531_ $$astars: massive
000005090 6531_ $$astars: winds
000005090 6531_ $$aoutflows
000005090 700__ $$aFenech, D. M.
000005090 700__ $$aPrinja, R. K.
000005090 700__ $$aBlomme, R.
000005090 700__ $$aYates, J. A.
000005090 700__ $$aDrake, J. J.
000005090 700__ $$aEyres, S. P. S.
000005090 700__ $$aRichards, A. M. S.
000005090 700__ $$aStevens, I. R.
000005090 700__ $$aWright, N. J.
000005090 700__ $$aClark, J. S.
000005090 700__ $$aDougherty, S.
000005090 700__ $$aPittard, J. M.
000005090 700__ $$aSmith, H. A.
000005090 700__ $$aVink, J. S.
000005090 773__ $$cA64$$pAstronomy & Astrophysics$$v637$$y2020
000005090 8560_ $$fronny.blomme@observatoire.be
000005090 85642 $$ahttps://ui.adsabs.harvard.edu/abs/2020A%26A...637A..64M/abstract
000005090 905__ $$apublished in
000005090 980__ $$aREFERD