Edinburgh Research Explorer

The Complex Structure of Stars in the Outer Galactic Disk as Revealed by Pan-STARRS1

Research output: Contribution to journalArticle

  • Colin T. Slater
  • Eric F. Bell
  • Edward F. Schlafly
  • Eric Morganson
  • Nicolas F. Martin
  • Hans-Walter Rix
  • David Martinez-Delgado
  • Rosemary F. G. Wyse
  • William S. Burgett
  • Kenneth C. Chambers
  • Peter W. Draper
  • Klaus W. Hodapp
  • Nicholas Kaiser
  • Eugene A. Magnier
  • Nigel Metcalfe
  • Paul A. Price
  • John L. Tonry
  • Richard J. Wainscoat
  • Christopher Waters

Related Edinburgh Organisations

Original languageEnglish
Article number9
Number of pages8
JournalAstrophysical Journal
Volume791
Issue number1
DOIs
Publication statusPublished - 1 Aug 2014

Abstract

We present a panoptic view of the stellar structure in the Galactic disk's outer reaches commonly known as the Monoceros Ring, based on data from Pan-STARRS1. These observations clearly show the large extent of the stellar overdensities on both sides of the Galactic disk, extending between b = -25° and b = +35° and covering over 130° in Galactic longitude. The structure exhibits a complex morphology with both stream-like features and a sharp edge to the structure in both the north and the south. We compare this map to mock observations of two published simulations aimed at explaining such structures in the outer stellar disk, one postulating an origin as a tidal stream and the other demonstrating a scenario where the disk is strongly distorted by the accretion of a satellite. These morphological comparisons of simulations can link formation scenarios to observed structures, such as demonstrating that the distorted-disk model can produce thin density features resembling tidal streams. Although neither model produces perfect agreement with the observations—the tidal stream predicts material at larger distances that is not detected while in the distorted disk model, the midplane is warped to an excessive degree—future tuning of the models to accommodate these latest data may yield better agreement.

    Research areas

  • galaxies: evolution, galaxies: interactions, Galaxy: disk, Galaxy: structure, MAJOR DWARF GALAXY, HIERARCHICAL SATELLITE ACCRETION, ANTICENTER STELLAR STRUCTURE, EXPLORING HALO SUBSTRUCTURE, DARK-MATTER SUBSTRUCTURE, RADIAL-VELOCITY SURVEY, MILKY-WAY, MONOCEROS RING, CANIS-MAJOR, LATITUDE STRUCTURES

ID: 18632703