Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
The Mass of M31
Search
Sponsored
·
Your Podcast. Everywhere. Effortlessly.
Share. Educate. Inspire. Entertain. You do you. We'll handle the rest.
→
Dan Foreman-Mackey
July 25, 2012
Science
0
170
The Mass of M31
Dan Foreman-Mackey
July 25, 2012
Tweet
Share
More Decks by Dan Foreman-Mackey
See All by Dan Foreman-Mackey
Open software for Astronomical Data Analysis
dfm
0
180
Open Software for Astrophysics, AAS241
dfm
2
570
My research talk for CCA promotion
dfm
1
800
Astronomical software
dfm
1
760
emcee-odi
dfm
1
700
Exoplanet population inference: a tutorial
dfm
3
490
Data-driven discovery in the astronomical time domain
dfm
6
740
TensorFlow for astronomers
dfm
6
850
How to find a transiting exoplanets
dfm
1
490
Other Decks in Science
See All in Science
(2025) Balade en cyclotomie
mansuy
0
450
あなたに水耕栽培を愛していないとは言わせない
mutsumix
1
250
Performance Evaluation and Ranking of Drivers in Multiple Motorsports Using Massey’s Method
konakalab
0
140
デジタルアーカイブの教育利用促進を目指したメタデータLOD基盤に関する研究 / Research on a Metadata LOD Platform for Promoting Educational Uses of Digital Archives
masao
0
150
論文紹介 音源分離:SCNET SPARSE COMPRESSION NETWORK FOR MUSIC SOURCE SEPARATION
kenmatsu4
0
520
NDCG is NOT All I Need
statditto
2
2.8k
Distributional Regression
tackyas
0
340
防災デジタル分野での官民共創の取り組み (1)防災DX官民共創をどう進めるか
ditccsugii
0
510
Algorithmic Aspects of Quiver Representations
tasusu
0
190
機械学習 - K近傍法 & 機械学習のお作法
trycycle
PRO
0
1.3k
データベース15: ビッグデータ時代のデータベース
trycycle
PRO
0
440
Celebrate UTIG: Staff and Student Awards 2025
utig
0
790
Featured
See All Featured
Understanding Cognitive Biases in Performance Measurement
bluesmoon
32
2.8k
[SF Ruby Conf 2025] Rails X
palkan
1
760
Prompt Engineering for Job Search
mfonobong
0
160
エンジニアに許された特別な時間の終わり
watany
106
230k
Crafting Experiences
bethany
1
49
Designing for humans not robots
tammielis
254
26k
JavaScript: Past, Present, and Future - NDC Porto 2020
reverentgeek
52
5.8k
Imperfection Machines: The Place of Print at Facebook
scottboms
269
14k
Organizational Design Perspectives: An Ontology of Organizational Design Elements
kimpetersen
PRO
1
230
The Pragmatic Product Professional
lauravandoore
37
7.1k
Rebuilding a faster, lazier Slack
samanthasiow
85
9.4k
Beyond borders and beyond the search box: How to win the global "messy middle" with AI-driven SEO
davidcarrasco
1
56
Transcript
THE MASS OF M31 THE FULLY SELF-CONSISTENT DYNAMICAL MODEL GALAXY
COFFEE MPIA 2012
DAN FOREMAN-MACKEY DANFM.CA GITHUB.COM/DFM NEW YORK UNIVERSITY LARRY WIDROW WITH:
QUEEN'S UNIVERSITY, CANADA
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...
WHAT HAVE WE DONE? BUILT A MODEL OF ANDROMEDA USING
A LOT OF DATASETS SELF-CONSISTENTLY PHYSICALLY MOTIVATED * *WAIT TWO SLIDES
van der Marel & Guhathakurta (2008) Widrow, Pym & Dubinski
(2005) Evans & Wilkinson (2000) Kuijken & Dubinski (1995) WHERE DOES THIS COME FROM?
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.
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 ⇢
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
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
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
Generative Model Likelihood Function ☁ x
Generative Model Likelihood Function ☁ x emceethe MCMC Hammer arxiv.org/abs/1202.3665
danfm.ca/emcee github.com/dfm/emcee paper documentation issues/contributions
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]
None
BONUS
BONUS