The Proper-motion Field along the Magellanic Bridge: A New Probe of the LMC–SMC Interaction
Sohn, Sangmo Tony
van der Marel, Roeland P.
Del Pino, Andrés
Linden, Sean T.
Fritz, Tobias K.
AffiliationUniv Arizona, Steward Observ
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationPaul Zivick et al 2019 ApJ 874 78
Rights© 2019. The American Astronomical Society. All rights reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractWe present the first detailed kinematic analysis of the proper motions (PMs) of stars in the Magellanic Bridge, from both the Gaia Data Release 2 catalog and from Hubble Space Telescope (HST) Advanced Camera for Surveys data. For the Gaia data, we identify and select two populations of stars in the Bridge region, young main-sequence (MS) and red giant stars. The spatial locations of the stars are compared against the known H I gas structure, finding a correlation between the MS stars and the H I gas. In the HST fields our signal comes mainly from an older MS and turnoff population, and the PM baselines range between similar to 4 and 13 yr. The PMs of these different populations are found to be consistent with each other, as well as across the two telescopes. When the absolute motion of the Small Magellanic Cloud is subtracted out, the residual Bridge motions display a general pattern of pointing away from the Small Magellanic Cloud toward the Large Magellanic Cloud. We compare in detail the kinematics of the stellar samples against numerical simulations of the interactions between the Small and Large Magellanic Clouds, and find general agreement between the kinematics of the observed populations and a simulation in which the Clouds have undergone a recent direct collision.
VersionFinal published version
SponsorsNASA through a grant from the Space Telescope Science Institute [GO-13834]; NASA [NAS5-26555]; Gaia Multilateral Agreement