Stellar populations in the Magellanic bridge

DOI

We report the discovery of a young stellar bridge that forms a continuous connection between the Magellanic Clouds. This finding is based on number density maps for stellar populations found in data gathered by OGLE-IV that fully cover over 270 deg^2^ of the sky in the Magellanic Bridge area. This is the most extensive optical survey of this region to date. We find that the young population is present mainly in the western half of the MBR, which, together with the newly discovered young population in the eastern Bridge, form a continuous stream of stars connecting both galaxies along {delta}~-73.5 deg. The young population distribution is clumped, with one of the major densities close to the SMC and the other fairly isolated and located approximately mid-way between the Clouds, which we call the OGLE island. These overdensities are well matched by H I surface density contours, although the newly found young population in the eastern Bridge is offset by ~2 deg north from the highest H I density contour. We observe a continuity of red clump stars between the Magellanic Clouds which represent an intermediate-age population. Red clump stars are present mainly in the southern and central parts of the Magellanic Bridge, below its gaseous part, and their presence is reflected by a strong deviation from the radial density profiles of the two galaxies. This may indicate either a tidal stream of stars, or that the stellar halos of the two galaxies overlap. On the other hand, we do not observe such an overlap within an intermediate-age population represented by the top of the red giant branch and the asymptotic giant branch stars. We also see only minor mixing of the old populations of the Clouds in the southern part of the Bridge, represented by the lowest part of the red giant branch.

Cone search capability for table J/ApJ/795/108/table2 (Number densities for three stellar populations: the young population (YP), the red clump (RC), and the red giant branch (RGB) stars)

Identifier
DOI http://doi.org/10.26093/cds/vizier.17950108
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/ApJ/795/108
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/795/108
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/795/108
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/ApJ/795/108
Provenance
Creator Skowron D.M.; Jacyszyn A.M.; Udalski A.; Szymanski M.K.; Skowron J.,Poleski R.; Kozlowski S.; Kubiak M.; Pietrzynski G.; Soszynski I.; Mroz P.,Pietrukowicz P.; Ulaczyk K.; Wyrzykowski L.
Publisher CDS
Publication Year 2017
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Galactic and extragalactic Astronomy; Natural Sciences; Physics; Stellar Astronomy