Open AccessA panoramic view of M81: new stellar systems in the debris field
Author(s) -
Mouhcine M.,
Ibata R.
Publication year - 2009
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2009.15135.x
Subject(s) - physics , red supergiant , stars , astronomy , astrophysics , galaxy , star formation , supergiant , spiral galaxy , large binocular telescope , red giant branch , stellar collision , dwarf galaxy , young stellar object , metallicity , stellar evolution
Using the MegaCam imager on the Canada–France–Hawaii Telescope, we have resolved individual stars in the outskirts of the nearby large spiral galaxy M81 (NGC 3031) well below the tip of the red giant branch of metal‐poor stellar populations over ∼60 × 58 kpc 2 . In this paper, we report the discovery of new young stellar systems in the outskirts of M81. The most prominent feature is a chain of clumps of young stars distributed along the extended southern H i tidal arm connecting M 81 and NGC 3077. The colour–magnitude diagrams of these stellar systems show plumes of bright main sequence stars and red supergiant stars, indicating extended events of star formation. The main sequence turn‐offs of the youngest stars in the systems are consistent with ages of ∼40 Myr. The newly reported stellar systems show strong similarities with other known young stellar systems in the debris field around M81, with their properties best explained by these systems being of tidal origin.