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The Mass of M31

The Mass of M31

Dan Foreman-Mackey

July 25, 2012
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  1. WHAT DO WE WANT TO DO? BUILD A TOOL FOR

    DYNAMICAL MODELING OF DISK GALAXIES USING ALL AVAILABLE DATASET SELF-CONSISTENTLY PHYSICALLY MOTIVATED i.e. not mass modeling...
  2. WHAT HAVE WE DONE? BUILT A MODEL OF ANDROMEDA USING

    A LOT OF DATASETS SELF-CONSISTENTLY PHYSICALLY MOTIVATED * *WAIT TWO SLIDES
  3. van der Marel & Guhathakurta (2008) Widrow, Pym & Dubinski

    (2005) Evans & Wilkinson (2000) Kuijken & Dubinski (1995) WHERE DOES THIS COME FROM?
  4. Radius HI-rotation curve Corbelli et al. (2010) surface brightness profile

    Barmby et al. (2006) satellite galaxy kinematics PAndAS, SPLASH, et al. Conn et al. (2011, in prep) ~10 kpc ~500 kpc Data PLUS: HALO STARS GLOBULAR CLUSTERS PLANETARY NEBULAE ETC.
  5. GALACTICS f(E, Lz, Ez) = fh(E) + fb(E) + fd(E,

    LzEz) ⇢(r, z) = ⇢h( (r, z)) + ⇢b( (r, z)) + ⇢d(r, z) r2 = 4 ⇡ G ⇢
  6. GALACTICS f(E, Lz, Ez) = fh(E) + fb(E) + fd(E,

    LzEz) ⇢(r, z) = ⇢h( (r, z)) + ⇢b( (r, z)) + ⇢d(r, z) r2 = 4 ⇡ G ⇢ Generative Model
  7. GALACTICS f(E, Lz, Ez) = fh(E) + fb(E) + fd(E,

    LzEz) ⇢(r, z) = ⇢h( (r, z)) + ⇢b( (r, z)) + ⇢d(r, z) r2 = 4 ⇡ G ⇢ Generative Model Likelihood Function
  8. GALACTICS f(E, Lz, Ez) = fh(E) + fb(E) + fd(E,

    LzEz) ⇢(r, z) = ⇢h( (r, z)) + ⇢b( (r, z)) + ⇢d(r, z) r2 = 4 ⇡ G ⇢ Generative Model Likelihood Function 19 Parameters
  9. Generative Model Likelihood Function ☁ x emceethe MCMC Hammer arxiv.org/abs/1202.3665

    danfm.ca/emcee github.com/dfm/emcee paper documentation issues/contributions
  10. 40 60 80 100 120 140 160 R [arcmin] 180

    200 220 240 260 280 300 320 vcirc [km s 1] 100 101 102 R [arcmin] 15 16 17 18 19 20 21 22 23 24 µ [mag arcsec 2]