English

2D kinematics of massive stars near the Galactic Center

Solar and Stellar Astrophysics 2020-11-18 v2 Astrophysics of Galaxies

Abstract

The presence of massive stars (MSs) in the region close to the Galactic Center (GC) poses several questions about their origin. The harsh environment of the GC favors specific formation scenarios, each of which should imprint characteristic kinematic features on the MSs. We present a 2D kinematic analysis of MSs in a GC region surrounding Sgr A* based on high-precision proper motions obtained with the Hubble Space Telescope. Thanks to a careful data reduction, well-measured bright stars in our proper-motion catalogs have errors better than 0.5 mas yr1^{-1}. We discuss the absolute motion of the MSs in the field and their motion relative to Sgr A*, the Arches and the Quintuplet. For the majority of the MSs, we rule out any distance further than 3-4 kpc from Sgr A* using only kinematic arguments. If their membership to the GC is confirmed, most of the isolated MSs are likely not associated with either the Arches or Quintuplet clusters or Sgr A*. Only a few MSs have proper motions suggesting they are likely members of the Arches cluster, in agreement with previous spectroscopic results. Line-of-sight radial velocities and distances are required to shed further light on the origin of most of these massive objects. We also present an analysis of other fast-moving objects in the GC region, finding no clear excess of high-velocity escaping stars. We make our astro-photometric catalogs publicly available.

Keywords

Cite

@article{arxiv.2010.10964,
  title  = {2D kinematics of massive stars near the Galactic Center},
  author = {Mattia Libralato and Daniel J. Lennon and Andrea Bellini and Roeland van der Marel and Simon J. Clark and Francisco Najarro and Lee R. Patrick and Jay Anderson and Luigi R. Bedin and Paul A. Crowther and Selma E. de Mink and Christopher J. Evans and Imants Platais and Elena Sabbi and Sangmo Tony Sohn},
  journal= {arXiv preprint arXiv:2010.10964},
  year   = {2020}
}

Comments

28 pages, 33 figures, 9 tables. Accepted for publication in MNRAS. [v3: Fixed bibliography]