Dwarf Galaxies and Galaxy Formation

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Dwarf Galaxies and Galaxy Formation
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• Valerie Bick
• University of California, Santa Cruz
• Research Mentor Constance Rockosi
• Home Institution California Polytechnic State
  University,
• San Luis Obispo

Image courtesy of Hope.co.nz
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Outline
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• Structure of a Disk Galaxy
• The Theorists Prediction
• The Project
• Data Collection Analysis
• Simulation
• Calculations
• Results
• Future Project

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Structure of a Disk Galaxy
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Like the Milky Way
Bulge
Disk
Halo
Image courtesy of Sloan Digital Sky Survey (SDSS)
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The Theorists Prediction
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• Theorists predict Milky Way partially formed by
  dwarf galaxies
• Dwarf galaxies interact with gravitational
  potential of Milky Way and are pulled apart, yet
  stars maintain the same average Doppler velocity

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Our Project
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Image courtesy of the SDSS
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Data Collection
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• Retrieved data from Sloan Digital Sky
  Survey/SkyServer
• Stars with all same absolute magnitude
• ? fainter stars farther away
• Split data into fainter and brighter stars

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Simulation
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Calculations
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• Red bars uncertainty in each bin v(number of
  objects in each bin, for the model)
• Significance calculation
• - Ratio amount of data outside model
• uncertainty
• - Significance calc v((data model)²)/v(model)

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Results
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• Peaks 10 of the total data are robustly
  detectable
• As the percentage increases, the peaks are easier
  to detect
• Test sensitivity could be improved if fit model
  independently of data
• Model is equally sensitive to half-max peaks and
  center peaks

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Conclusions Future
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• Expand our method
• Implement model independent of data
• Apply to entire data set check curve fit
• Optimize the amount of data and bin size
• Use the results to answer the ultimate question
  did dwarf galaxies contribute to the formation of
  the galaxys disk?

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Many Thanks To
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• Connie Rockosi
• Lynne Raschke
• Hilary OBryan
• The Center for Adaptive Optics
• Funding provided through the Center for
  Adaptive Optics, a National Science Foundation
  Science and Technology Center (STC), AST-987683.