AY202a Galaxies & DynamicsLecture 1: Introduction

Organization, History, Basic Cosmology Prof. John Huchra, P309TA Joseph Munoz, P203

JPH’s Assistant Lisa Catella, P324M+W 10:00 - 11:30

Observatory Classroom

Course Outline & Structure

I. Introduction (4 Lectures)

II. Structure & Dynamics (6 Lectures)

III. Masses & Omega (2 Lectures)

IV. Galaxy Nuclei & AGN (3 Lectures)

V. Clustering (LSS) (5 Lectures)

VI. Formation & Evolution (3 Lectures)

VII. Extragalactic Distances (1 Lecture)

Resources, PS, Grading etc.

Website: www.cfa.harvard.edu/~huchra/ay202 will have PS, Solutions, Schedules, ReferencesProblem Sets approximately every 2 weeks (6 total) ~ one per major section.Take home Final Exam, tentatively due Dec 14 Grades: PS 50% Exam 40% Class 10%Sections: TBA, Office hours by appointmentPaper of the Week --- Classic or Recent ArXiv

Texts

Extragalactic Astronomy & Cosmology, 2006,

P. Schneider (Berlin: Springer).

Galactic Dynamics, 2008, J. Binney & S. Tremaine, (Princeton: Princeton)

Galactic Astronomy}, 1998, J. Binney & M. Merrifield (Princeton: Princeton).

Coop, Amazon or JPH’s booksellers list.

A Protagonist

How Astronomers See the World

“My Work is to Stare into Space”

IAU, Commissions 27, 30 & 40

Teamsters, Local 560 (Newark, NJ) Another Protagonist

A Brief History of Extragalactic Astronomy:

~ 1750 Early Rumblings of “Island Universes”

from I. Kant, T. Wright, P. Laplace.

This seems to have been forgotten soon after.

1800’s Catalogs of “Things” but no understanding.

de la Caille, Messier, Herschel3, Dreyer William, Caroline & John

~ 1875 The Discovery of the Galaxy ---

Kapteyn’s Universe

1890’s Galaxy Photography (Keeler)

The Sun

R.Pogge 2007

1910 Removal of the Solar-Centric view1900-1920 Shapley and the Great Debate 1907 Bohlin --- M31 Parallax 1918 Van Maanen --- M31 Parallax 1885 S Andromeda = SN1885a Large reflectors + Photographic Plates 1912 Galaxy Spectra (Slipher)1920 The Shapley-Curtis debate Shapley + Globular Clusters + Cepheids1924 Hubble & the Hooker --- NGC 6822

Cepheids, eventually M31 Cepheids

Shapley’s “Universe”

Milky Way

1910-1930 Theory! Einstein, Friedmann, deSitter, Lemaitre, Tolman, Robertson …

1922 Opik’s M31 Mass-to-Light ratio

L = 4πr2 GMm/r = ½ mv2

M = ½ v2r/G, r = D

so M/L = ½

and Opik estimated D of M31 at 450 kpc.

v2 1 1G 4πD

1929 Hubble (+Slipher) à Velocity-Distance Law

• 1930’s Hubble’s Classification Scheme for Galaxies (Tuning Fork Diagram)

• N.B. Absolutely necessary but wrong interpretation, set galaxy evolution back 20 years!

• Hubble’s Galaxy Counts (Humason)• Zwicky & Smith DARK MATTER• 1940’s Galactic Dust, Stellar Populations,

Hubble Diagram

1948 Gamow & the Hot Big Bang1950’s deVaucouleurs’ Local “Supergalaxy” Rubin: Flows Dicke: CMB HMS Velocities + Hubble Diagram Baade & Sandage: H0 revisions Minkowski: Radio galaxies1960’s The Hubble Constant Debate “On the Ability of the 200” to Distinguish Among World Models” Tinsley: Stellar Evolution -->

Galaxy Evolution

Greenstein & Schmidt: Quasars

Arp: Peculiar Galaxies

Spinrad &Taylor : Population

Synthesis

Page: Galaxy Masses

1970’s Stability & Halos (Toomre)

Starbursts

H0!!! q0!!!

First Feeble Redshift Surveys

CMB Dipole

1970’s Galaxy Clusters & X-Rays

Gravitational Lenses

Galaxy Formation

1980’s Large-Scale Structure

Large Scale Flows & Cold Dark

Matter Rise of “SCDM”

Galaxy Counts

H0!!!!

IRAS & Dusty Starbursts

1990’s COBE: 2.723 K + fluctuations

Biased Galaxy Formation

Unified AGN Models

Λ!!!!! (who’d a thunk it!)

Start of Concordance Cosmology

HST and Galaxy Evolution

2000+ The Cosmic Web

GRB’s

Final fall of “SCDM”

Re-ionization & First Light?

COSMOLOGY is a modern subject:

The basic framework for our current

view of the Universe rests on ideas and

discoveries (mostly) from the early 20th

century.

Basics:

Einstein’s General Relativity

The Copernican Principle

Fundamental Observations & Principles

Fundamental Observations: The Sky is Dark at Night (Olber’s P.)

The Universe is Homogeneous on

large scales (c.f. the CMB)

The Universe is generally Expanding

The Universe has Stuff in it, and the

stuff is consistent with a hot

origin: Tcmb = 2.725o

Olber’s Paradox HST UDF

BLANK SPACE

COBE Fluctuations

t/t < 10-5, i.e. much smoother than a baby’s bottom!

Hubble’s Discovery of Expansion

Stuff

Reading Assignment

For next Wednesday (we’re off Monday)

“Extragalactic Nebulae” by Edwin Hubble, ApJ 64, 321 (1926)

Read, Outline,be prepared to discuss Hubble’smajor findings and conclusions.