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Extragalactic Astronomy
and Cosmology
(PHYS 316)
Volker Beckmann
Joint Center for Astrophysics, University of Maryland, Baltimore County
& NASA Goddard Space Flight Center, Exploration of the Universe Division
UMBC, August 31st, 2006
Overview
● General Information about this course
● Academic Integrity
● Grading
● Homework / Midterms / Final
● Outline of the course
● Getting started with some astronomy...
Graphic: ESA / V. Beckmann
About myself...
● master in physics at Hamburg University
(master thesis on X-ray astronomy) 1996
● PhD in astrophysics at Hamburg
Observatory and at Osservatorio Astronomico
di Brera (Milan/Italy) - studying the evolution
of distant galaxies (Luminosity Function of BL
Lac objects and Seyfert 2 galaxies) 2001
● 2001-2003: working in Geneva
(Switzerland) on a hard X-ray satellite project
(INTEGRAL)
About myself...
● since October 2003: working for UMBC at
NASA/Goddard Space Flight Center
● distant galaxies in hard X-rays
● INTEGRAL
Academic Integrity
● By enrolling in this course, each student
assumes the responsibilities of an active
participant in UMBC’s scholarly
community in which everyone’s academic
work and behavior are held to the highest
standards of honesty. Cheating,
fabrication, plagiarism, and helping others
to commit these acts are all forms of
academic dishonesty, and they are
wrong.
Academic Integrity
● Academic misconduct could result in
disciplinary action that may include, but is
not limited to, suspension or dismissal. To
read the full Student Academic Conduct
Policy, consult the UMBC Student
Handbook, the Faculty Handbook, or the
UMBC Policies section of the UMBC
Directory.
Grading
● 30% homework: once a week, 11
assignments in total
● 35% midterm: October 5 & November 7
● 35% final exam: December 14-20
● participation in the course is also
considered!
Homework
● 30% homework
● you are encouraged to work in teams of 2 but everybody has to hand in his/her
homework.
● Use resources:
● course webpage
● library
● www - careful! Not every website tells the
truth! Wikipedia might be wrong!
● Use refereed / text book material whenever
possible and cite correctly
● include all intermediate steps (partial credit)
Course website
●
lheawww.gsfc.nasa.gov/~beckmann/physics316
● schedule
● literature
● homework
● who’s who page
● contact information
Literature
● Required text book:
● Barbara Ryden, “Introduction to Cosmology”
(2003), Addison Wesley, ISBC 0-8053-8912-1;
about 65.- $
● optional: Andrew Liddle, “An Introduction to
Modern Cosmology”, John Wiley & Sons Ltd
(about 40.- $)
● nice to read: Steven Weinberg, “The First
Three Minutes”, BasicBooks (about 11.- $)
● have a look on the books today here after the
class!
About the course
● Tuesdays and Thursdays 8:30 a.m. (uff!)
● starts with repeating last lectures main points
● discussing homework (if any)
● no script - we’ll follow the text book closely
● participation of students
● small quiz (not relevant for your grade) on
September 12th (Sep. 13 is last day to drop course
without a grade of “W”)
● contact me via e-mail:
[email protected]
● or during office hours (after lecture) in room 415
About the course
● sophomores to seniors in this course
● Prerequisite PHYS 122
● basic physics (gravitation, electromagnetic
waves, wave-particle dualism, elementary
particles)
● mathematics (some calculus)
● astrophysics not mandatory, but …
● what we will not use: advanced calculus,
tensor algebra, plasma physics ...
● What we will not do: learn complex formulas
by heart
Getting started
What’s cosmology ?
What do we have to know about the Universe
to do cosmology ?
Key questions?
Graphic: HST
Christmas you’ll be able to
answer...
● How is the cosmos evolving?
● What different models are there for the
evolution of the cosmos and what do they
predict?
● What might be the future of the universe?
● How can we describe the beginning of the
universe?
● What (anti-)particles and elements are
abundant in the universe and how did they
form?
● What observations led to today’s cosmology?
Christmas you’ll know something
about...
● Hubble law (observed increasing velocity with
increasing distance of galaxies)
● Friedmann equation (description of the
cosmological evolution)
● Dark matter
● Dark energy (cosmological constant)
● Inflation
● Nucleosynthesis
Astronomy
● Let’s start with some astronomy...
Foto by Scott Tucker
Foto by Steve Barrett
Phot
Foto: N.A. Sharp,
NOAO/AURAU/NSF
Planets of the solar system (Pluto is not considered a planet anymore)
Graphic: NASA
The Sun - just an ordinary star!
The Sun - just an ordinary star!
The Sun - just an ordinary star!
The Sun - a fusion reactor
Mass loss of the red giant star V838
Stellar evolution
● Gravitation -> star formation
● fusion -> main sequence evolution
● heavy stars (>10 solar masses): Supernova or
neutron stars
● solar type stars: white dwarfs
● <0.5 solar masses: brown dwarf
There are about
50 billion stellar
systems in the
Milkyway
Globular (star) Cluster M5
Zooming into the Globular Cluster M22
Star forming regions: the horsehead nebula in Orion
Star forming
regions: the
horsehead nebula
in the Orion
region
Star forming regions: M17
Movement of stars around the Galactic Center
Andromeda galaxy
M31.
Foto: T.A. Rector,
B.A.Wolpa,
NOAO/AURA/NSF
M101
Foto: George Jacoby,
Bruce Bohannan, Mark
Hanna,
NOAO/AURA/NSF
M104
Foto: Todd Boroson,
NOAO/AURA/NSF
M89
Foto:
NOAO/AURA/NSF
Coma Galaxy
Cluster
Photo: Omar LopezCruz, Ian Shelton,
NOAO/AURA/NSF
Galaxy Cluster
RDCS 1252.92927
Combined VLT
optical and Chandra
X-ray image
Large Scale Structure in the Universe
Simulation, Credits: F. Summers, L. Hernquist, M. White
Summary
- stars (suns) undergo evolution
- star formation (gravity)
- fusion (H and He burning)
- supernova or white dwarf
- milkyway is inhomogeneous: star
forming regions, globular clusters,
central massive black hole
- 5e10 stars in Milkyway (galaxy)
- about 1e11 galaxies in the universe
Summary
- galaxies come in different shape:
spiral (young), elliptical (old),
irregular (very young or disrupted)
- galaxies form groups: galaxy
clusters
- a lot of gas trapped in potential of
galaxy clusters