Halpha emission-line stars in molecular clouds III. Canis Major

Abstract

A deep objective-prism survey for H-alpha emission stars towards the Canis Major star-forming clouds was performed. A total of 398 Halpha emitters were detected, 353 of which are new detections. There is a strong concentration of these H-alpha emitters towards the molecular clouds surrounding the CMa~OB1 association, and it is likely that these stars are young stellar objects recently born in the clouds. An additional population of H-alpha emitters is scattered all across the region, and probably includes unrelated foreground dMe stars and background Be stars. About 90% of the H-alpha emitters are detected by WISE, of which 75% was detected with usable photometry. When plotted in a WISE colour-colour diagram it appears that the majority are Class II YSOs. Coordinates and finding charts are provided for all the new stars, and coordinates for all the detections. We searched the Gaia-DR2 catalogue and from 334 Halpha emission stars with useful parallaxes, we selected a subset of 98 stars that have parallax errors of less than 20% and nominal distances in the interval 1050 to 1350 pc that surrounds a strong peak at 1185 pc in the distance distribution. Similarly, Gaia distances were obtained for 51 OB-stars located towards Canis Major and selected with the same parallax errors as the H-alpha stars. We find a median distance for the OB stars of 1182 pc, in excellent correspondence with the distance from the H-alpha stars. Two known runaway stars are confirmed as members of the association. Finally, two new Herbig-Haro objects are identified.

References in corpus (16)

• The Gaia mission
• The Milky Way in Molecular Clouds: A New Complete CO Survey
• Near-Infrared Photometric Variability of Stars Toward the Orion A Molecular Cloud
• The first Hi-GAL observations of the outer Galaxy: a look to star formation in the third Galactic quadrant in the longitude range 216.5 < l < 225.5
• Gaia Data Release 1. Testing the parallaxes with local Cepheids and RR Lyrae stars
• The evolution of stars in the Taurus-Auriga T association
• A WISE Census of Young Stellar Objects in Canis Major
• The relation between 13CO(2-1) line width in molecular clouds and bolometric luminosity of associated IRAS sources
• Star formation history of CMa R1: I. Wide-field X-ray study of the young stellar population
• Star formation activity in the Galactic H II region Sh2-297
• Identifying Young Stellar Objects in the Outer Galaxy: l = 224 deg Region in Canis Major
• New Young Star Candidates in BRC 27 and BRC 34
• Runaways and shells around the CMa OB1 association
• Halpha emission-line stars in molecular clouds. II. The M42 region
• Spectroscopic characterization of X-ray emitting young stars associated with the Sh 2-296 nebula
• The long-period massive binary HD~54662 revisited

Cited by in corpus (5)

• OB associations and their origins
• Canis Major OB1 stellar groups contents revealed by Gaia
• Searching for active low-mass stars in CMa star-forming region: multi-band photometry with T80S
• Comparing the spatial and kinematic distribution of gas and young stars around the shell-like structure in the CMa OB1 association
• A closer look at the young stellar group around Sh 2-295