Astr 5460     Fri., Feb. 7, 2003
   Today: WIRO: Tonight!
Reminders/Assignments
Longair, Ch. 2 (Large Scale Struct.)
Start Longair, Ch. 3 (Galaxies)
 Unless noted, all figs and eqs from Longair.

WIRO -- logistics
We will leave after colloquium, about 5PM.  Sabrina and I are driving.
Bring food and drinks (only water will be available at WIRO).  We can stop on the way if necessary, but better to get early.
Dress WARMLY!  Overkill is OK.
May stay until morning if weather is good.  Beds are available at WIRO.

WIRO – science+
Mike Pierce is putting on the Prime Focus camera (see webpage for more info).
Jon Darnel has one project with Chip K.  M33 blue imaging, 1-2 hours.
Pretty 3-color pictures for a calendar – bring targets!  Note that there is no internet connection right now.
I’m working on developing a good project.
Group Assignment: Take notes and develop a WIRO/PFC Observer’s Handbook.

Reminders/Preliminaries
Astro-ph preprints:
http://xxx.lanl.gov/astro-ph
Discuss homework assignments (briefly!)
Redshifted BB curve
MAP, PLANCK (Kiminki)

Hubble’s Law and Expansion

Hubble’s Law and Expansion

Hubble’s Law and Expansion

Hubble’s Law and Expansion

Hubble’s Law and Expansion

Hubble’s Law and Expansion

Hubble’s Law and Expansion

Hubble’s Law and Expansion

Conclusions
On the largest scales it is appropriate to impose the conditions of isotropy and homogeneity, plus uniform expansion.
These simplifications plus GR provide relatively simple “world models” that provide a framework for cosmology and the origin of galaxies and other large scale structures.

Chapter 3: Galaxies
General, basic properties outlined here.  More will be covered in ASTR 5440.
Classifications
Luminosity Functions
Galaxy Masses
Elliptical Galaxies
Spiral Galaxies
Correlations with Types

“Tuning Fork” Diagram

Spiral types
The nuclear bulge is population II  (old stars)
So the Sa – Sc sequence is consistent with
 little gas
Þ more gas

Elliptical Galaxy: M87

Irregular Galaxies: Magellanic Clouds

More on Classifications

Frequency of Galaxy Types

Frequency of Galaxy Types

Frequency of Galaxy Types

The Local Group of Galaxies
Galaxies live in clusters
Rich clusters:  thousands of galaxies
Poor clusters:  Fewer than a thousand

The Coma Cluster

Interacting Galaxies: The Antennae

Interacting Galaxies: Cartwheel

Effects of Collisions
Stars pass “through” each other, although orbits disrupted
Gas clouds collide
Gas stripped away from stars
Collisions cause bursts of star formation
Ellipticals may be galaxies which have suffered collisions
Spirals may be galaxies which have not suffered collisions
Joshua Barnes (Hawaii) and the Space Telescope Science Institude provide a simulation of the Antenna Galaxies: http://imgsrc.stsci.edu/op/pubinfo/pr/1997/34/images/anima.mov

Simulation of the Cartwheel Encounter
From the Space Telescope Science Institute which also provided the Cartwheel image in the textbook:
http://imgsrc.hubblesite.org/hu/discoveries/striking_encounters/graphics/cartwheel.mpg

Luminosity Functions
For Wednesday…