The Proper-motion Field along the Magellanic Bridge: A New Probe of the LMC–SMC Interaction

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.
Referencia bibliográfica

The Astrophysical Journal, Volume 874, Issue 1, article id. 78, 10 pp. (2019).

Fecha de publicación:
3
2019
Número de autores
9
Número de autores del IAC
1
Número de citas
40
Número de citas referidas
38
Descripción
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.
Proyectos relacionados
Una vista de nuestra galaxia, la Vía Láctea, con sus vecinos cercanos,  las Nubes de Magallanes
Evolución Galáctica en el Grupo Local

La formación y evolución de galaxias es un problema fundamental en Astrofísica. Su estudio requiere “viajar atrás en el tiempo”, para lo cual hay dos enfoques complementarios. El mas extendido consiste en analizar las propiedades de las galaxias a diferentes distancias cosmológicas. Nuestro equipo se concentra en el otro enfoque, denominado

Matteo
Monelli