Mapping the Galactic halo. III. Simulated observations of tidal streams

Paul Harding, Heather L. Morrison, Edward W. Olszewski, John Arabadjis, Mario Mateo, R. C. Dohm-Palmer, Kenneth C. Freeman, John E. Norris

Research output: Contribution to journalArticle

41 Scopus citations

Abstract

We have simulated the evolution of tidal debris in the Galactic halo in order to guide our ongoing survey to determine the fraction of halo mass accreted via satellite infall. Contrary to naive expectations that the satellite debris will produce a single narrow velocity peak on a smooth distribution, there are many different signatures of substructure, including multiple peaks and broad but asymmetrical velocity distributions. Observations of the simulations show that there is a high probability of detecting the presence of tidal debris with a pencil-beam survey of 100 deg2. In the limiting case of a single 107 M satellite contributing 1% of the luminous halo mass the detection probability is a few percent using just the velocities of 100 halo stars in a single 1 deg2 field. The detection probabilities scale with the accreted fraction of the halo and the number of fields surveyed. There is also surprisingly little dependence of the detection probabilities on the time since the satellite became tidally disrupted, or on the initial orbit of the satellite, except for the time spent in the survey volume.

Original languageEnglish (US)
Pages (from-to)1397-1419
Number of pages23
JournalAstronomical Journal
Volume122
Issue number3
DOIs
StatePublished - Sep 1 2001

Keywords

  • Galaxy: formation
  • Galaxy: halo
  • Galaxy: kinematics and dynamics

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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    Harding, P., Morrison, H. L., Olszewski, E. W., Arabadjis, J., Mateo, M., Dohm-Palmer, R. C., Freeman, K. C., & Norris, J. E. (2001). Mapping the Galactic halo. III. Simulated observations of tidal streams. Astronomical Journal, 122(3), 1397-1419. https://doi.org/10.1086/322995