Bibcode
Zivick, P.; Kallivayalil, Nitya; Besla, Gurtina; Sohn, Sangmo Tony; van der Marel, Roeland P.; del Pino, Andrés; Linden, Sean T.; Fritz, T. K.; Anderson, J.
Bibliographical reference
The Astrophysical Journal, Volume 874, Issue 1, article id. 78, 10 pp. (2019).
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3
2019
Journal
Citations
46
Refereed citations
42
Description
We 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 ∼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.
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Matteo
Monelli