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Studying the Accretion History of the Milky Way

POSTER

Abstract

An important goal of cosmology is to determine the Milky Way's accretion history, the history of dwarf galaxies accreting to form the stellar halo. Each individual accretion event forms a unique structure in the halo, and these features, known as substructure, explain the galaxy's accretion history. To examine substructure, we compare data of the HALO7D survey fields from the Gaia space observatory to the Besan\c{c}on model of the Milky Way, which notably has no substructure. A comparison between galactic latitude and number of stars illustrates that both the Besan\c{c}on model and Gaia data show an increase in stars near low latitudes, but little variation due to substructure. Similar trends were found between proper motion and color, with larger ranges of proper motion corresponding with increasing color while magnitude is constant. Due to the large error in Gaia parallax, the inverse relationship between distance and proper motion present in the Besan\c{c}on model was absent in Gaia data. We determined that proxies such as proper motion versus color demonstrate a similarity between the Milky Way and Besan\c{c}on model, but do not yield substructural information. Future work includes comparison of LOS velocity from Keck DEIMOS spectra of stars in these fields.

Authors

  • William Huang

    Lynbrook High School

  • Ina Flood

    Saleh Research Centre, University of Hawaii at Manoa, California State University, Long Beach, University of California Berkeley, University of Arizona, California State University, Long Beach Department of Physics and Astronomy, University of California Los Angeles Department of Physics and Astronomy, University of California, San Diego, University of California, Davis, Donostia International Physics Center, Yale University, Argonne National Laboratory, SLAC - Natl Accelerator Lab, Heidelberg University, Indiana University-Perdue University Indianapolis, Humboldt State University, Indiana University, Syracuse University, University of California Santa Cruz, STAR Teacher Program, Monta Vista High School, Saint Francis High School, Lawrenceville School, INAF, Ben-Gurion University, STScI, University of California, Los Angeles, Wuhan University, Harvey Mudd College, University of Maryland

  • Ina Flood

    Saleh Research Centre, University of Hawaii at Manoa, California State University, Long Beach, University of California Berkeley, University of Arizona, California State University, Long Beach Department of Physics and Astronomy, University of California Los Angeles Department of Physics and Astronomy, University of California, San Diego, University of California, Davis, Donostia International Physics Center, Yale University, Argonne National Laboratory, SLAC - Natl Accelerator Lab, Heidelberg University, Indiana University-Perdue University Indianapolis, Humboldt State University, Indiana University, Syracuse University, University of California Santa Cruz, STAR Teacher Program, Monta Vista High School, Saint Francis High School, Lawrenceville School, INAF, Ben-Gurion University, STScI, University of California, Los Angeles, Wuhan University, Harvey Mudd College, University of Maryland

  • Ina Flood

    Saleh Research Centre, University of Hawaii at Manoa, California State University, Long Beach, University of California Berkeley, University of Arizona, California State University, Long Beach Department of Physics and Astronomy, University of California Los Angeles Department of Physics and Astronomy, University of California, San Diego, University of California, Davis, Donostia International Physics Center, Yale University, Argonne National Laboratory, SLAC - Natl Accelerator Lab, Heidelberg University, Indiana University-Perdue University Indianapolis, Humboldt State University, Indiana University, Syracuse University, University of California Santa Cruz, STAR Teacher Program, Monta Vista High School, Saint Francis High School, Lawrenceville School, INAF, Ben-Gurion University, STScI, University of California, Los Angeles, Wuhan University, Harvey Mudd College, University of Maryland

  • Ina Flood

    Saleh Research Centre, University of Hawaii at Manoa, California State University, Long Beach, University of California Berkeley, University of Arizona, California State University, Long Beach Department of Physics and Astronomy, University of California Los Angeles Department of Physics and Astronomy, University of California, San Diego, University of California, Davis, Donostia International Physics Center, Yale University, Argonne National Laboratory, SLAC - Natl Accelerator Lab, Heidelberg University, Indiana University-Perdue University Indianapolis, Humboldt State University, Indiana University, Syracuse University, University of California Santa Cruz, STAR Teacher Program, Monta Vista High School, Saint Francis High School, Lawrenceville School, INAF, Ben-Gurion University, STScI, University of California, Los Angeles, Wuhan University, Harvey Mudd College, University of Maryland

  • Ina Flood

    Saleh Research Centre, University of Hawaii at Manoa, California State University, Long Beach, University of California Berkeley, University of Arizona, California State University, Long Beach Department of Physics and Astronomy, University of California Los Angeles Department of Physics and Astronomy, University of California, San Diego, University of California, Davis, Donostia International Physics Center, Yale University, Argonne National Laboratory, SLAC - Natl Accelerator Lab, Heidelberg University, Indiana University-Perdue University Indianapolis, Humboldt State University, Indiana University, Syracuse University, University of California Santa Cruz, STAR Teacher Program, Monta Vista High School, Saint Francis High School, Lawrenceville School, INAF, Ben-Gurion University, STScI, University of California, Los Angeles, Wuhan University, Harvey Mudd College, University of Maryland

  • Ina Flood

    Saleh Research Centre, University of Hawaii at Manoa, California State University, Long Beach, University of California Berkeley, University of Arizona, California State University, Long Beach Department of Physics and Astronomy, University of California Los Angeles Department of Physics and Astronomy, University of California, San Diego, University of California, Davis, Donostia International Physics Center, Yale University, Argonne National Laboratory, SLAC - Natl Accelerator Lab, Heidelberg University, Indiana University-Perdue University Indianapolis, Humboldt State University, Indiana University, Syracuse University, University of California Santa Cruz, STAR Teacher Program, Monta Vista High School, Saint Francis High School, Lawrenceville School, INAF, Ben-Gurion University, STScI, University of California, Los Angeles, Wuhan University, Harvey Mudd College, University of Maryland

  • Ina Flood

    Saleh Research Centre, University of Hawaii at Manoa, California State University, Long Beach, University of California Berkeley, University of Arizona, California State University, Long Beach Department of Physics and Astronomy, University of California Los Angeles Department of Physics and Astronomy, University of California, San Diego, University of California, Davis, Donostia International Physics Center, Yale University, Argonne National Laboratory, SLAC - Natl Accelerator Lab, Heidelberg University, Indiana University-Perdue University Indianapolis, Humboldt State University, Indiana University, Syracuse University, University of California Santa Cruz, STAR Teacher Program, Monta Vista High School, Saint Francis High School, Lawrenceville School, INAF, Ben-Gurion University, STScI, University of California, Los Angeles, Wuhan University, Harvey Mudd College, University of Maryland