Transcript Third Year Astrophysics - University of Western Australia

Third Year Astrophysics
 12
lectures
-6 lectures on cosmology
-6 lectures on stellar evolution
 Power point slides on WebCT
 3 assignments, including literature review component
 Lectures based on Web resources
 Contact me whenever necessary: ext 2736, mob
0409687703,dgb@physics, rm4-67, basement lab, Gingin
95757591
Course Outline and Deadlines
Cosmology: 6 lectures: see key learning goals
Stellar Evolution: 6 lectures: see key learning goals
Excursion: Tuesday 1 April barbeque, cosmology and
astronomy field night if class chooses.
Deadline for written work: 1 week after last astro lecture
Key Learning Goals
 Cosmology
»Friedmann Cosmology and the Hubble Law
»Cosmic Microwave background
»Big Bang Nucleosynthesis
»Missing Mass and Dark Energy: SN and other
probes
 Stellar Evolution
»Evolution from HR Diagrams
»Stellar nucleosynthesis
»Equation of State for Degenerate Matter
»Evolution of stars to white dwarfs, neutron stars,
black holes and binary systems
Learning process
 Power
point presentations and follow up review by
you.
 Assignments including literature reviews
 Assessment:
»50% continuous assessment
» Final Examination
ALL WORK MUST BE COMPLETED TO RECEIVE A COURSE
MARK.
Final exam will be a bit like the assignment questions.
Lecture
Topic
1
Friedmann Cosmology
2
Theory of Inflationary Cosmology
3
Cosmic Microwave Background
4
Theory of Dark Matter and Dark Energy
5
Observational Evidence for Dark Energy and Dark Matter
6
Structure Formation
7
Stellar evolution
8
Degenerate Stars and Gravitational Collapse
9
Supernova Mechanisms and Observation
10
Evolution of Binary Systems
11
Gravitational wave emission in binary systems
12
Compact Binary Systems with Black Holes
Friedmann Big Bang Cosmology
Derivation of Friedmann equations
Potential energy-kinetic energy and closure density
General relativistic solution: the shape of space
time
Friedmann Time: age of the universe and the
Hubble law.
The Cosmological Constant now and in the past.
Introduction to Theory of Inflationary
Cosmology
Problems with Standard Cosmology
Guths Inflation Theory
The Inflationary potential, false vacuums
Dilaton and Inflaton Models
Predictions from inflation theory
Nature and origin of the big bang
Cosmic microwave background
Black body radiation
Temperature evolution in radiation dominated universe
Decoupling of radiation and matter
Acoustic oscillations in the early universe
The angular power spectrum and determination of the
parameters of the universe
Future measurements of the cosmic background
Theory of Dark matter and Dark Energy
Theoretical possibilities for dark matter
Cold dark matter versus hot dark matter
The search for dark matter candidates
Dark matter and galactic mass distributions
Dark energy, negative pressure and equations of state
Dark energy and quintessence
Observation of dark matter and dark
energy
Evidence for Dark Matter:
a) galaxy rotation curves
b) clustering of galaxies
c) Cosmic microwave background acoustic oscillations
d) gravitational lensing
Evidence for dark Energy
Supernovae
Large Scale structure
Stellar Evolution
Thermal stability of stars
Nuclear physics of stellar evolution
HR diagrams and the Main sequence
Evolutionary tracks
Degenerate stars and gravitational
collapse.
Evidence for degenerate matter
Derivation of the ideal Fermi gas star…white dwarfs
Critical mass for neutron star
Observations of WDs and NSs.
Properties of neutron stars
Radio pulsars and x-ray pulsars
Supernova Mechanisms and
Observations
Critical Mass
Collapse and Bounce
Binary mechanisms
Supernova Classification and Observation
Supernovae and Gamma Ray Bursts
Role of neutrinos
Gravitational wave emission in
binary systems
Quadrupole formula for GW emission
Gravitational wave circularisation of orbits
Neutron star coalescence
Detection of neutron star coalescence events
Black hole binary coalescence
Testing black hole physics with binary inspiral
events
Evolution of Compact Binary Systems
Binary star systems: basic concepts
Evolution of isolated stars
Supernovae and birth of neutron stars and black holes
Stellar evolution in a binary system
Observations of close binary systems (X-ray, radio)
Coalescence of binary systems and gravitational wave
emission
Compact Binary Systems with Black
Holes
Binary star systems with compact component: basic
concepts
Nuclear detonation on neutron stars
Accretion disks around neutron stars and black holes
Gravitational wave emission from binary systems
Radio Observations of double pulsars
Coalescence of binary systems by gravitational wave
emission
Plagiarism
Non-referenced copying of sentences or paragraphs
How to search: Type key phrases into google.
Best proof: when errors are also copied.
50% plagiarism = plagiarism
What is permitted: quotation of text with full reference
(but this does not prove you learnt anything!).
It is in everyone’s interest to avoid plagiarism.
Plagiarism was detected in 2006 and 2007, in each case
having serious consequences for the individual concerned.
Literature review guidelines
Choose a recent research letter relevant to your topic
-google key words.
The letter should be brief (approx 5 pages max).
You need to show you have understood it.
The letter that you used should be fully referenced.
Referencing: Give titles and first author at least.
Reference can be web URL.
Referencing style your own choice
Write about 1 page: it needs to be written so a second
year student can understand it. You will lose marks for
copying unintelligible jargon.
Assignment 1: deadline end of week 3
1. Cosmology
A) Explain the concepts of angular size distance, luminosity distance and
red shift distance in cosmology
B) Use the Javascript cosmology calculator on Ned Wright’s homepage to
make plots of angular size distance and luminosity distance as a
function of red shift for sources from z=0 to z=100. Use the latest
cosmological parameters from the WMAP mission. Take care in
choosing axes.
C) Discuss why these quantities do not obey the laws of Euclidean
geometry.
2. Scale Size of Universe
Plot the scale size of the universe as a function of time in four epochs
a) inflationary epoch
b) the radiation dominated era
c) the matter dominated era
d) the dark energy dominated era
Literature Review: Review one of the latest 5 year results papers from
the WMAP mission, or any recent letter on cosmology on Astro-ph.
Please Include a copy of the letter you reviewed to assist in marking.
Assignment 2: deadline end of week 5
1. Cosmic Microwave Background
•
Explain the meaning of spherical harmonic decomposition of an image
b) Explain the significance of the peaks in the spherical harmonic deccomposition
of the WMAP data
c) Bonus marks challenge: Use spherical harmonic decomposition in Mathematica or
Matlab to decompose a photograph. Present the photograph and its
decomposition. (you can get full marks without this question but this will
confirm your understanding)
2. Supernovae
a) Explain the difference between Type 1a supernovae and other supernova types.
b) Explain the nuclear physics leading to gravitational collapse.
c) Investigate the physics of the detonation.
3. Literature review
Find a letter relevant to either question 1 or 2 and write a I page review following
the Literature Review guidelines. Please Include a copy of the letter you
reviewed to assist in marking.
Assignment 3 deadline 1 week after last lecture
1.
2.
3.
Degenerate matter
a) Use 5 or 6 bullet points to outline the derivation of the Chandrasekar
limit of white dwarfs
b) What factors influence the limiting mass of white dwarfs and neutron
stars. 1 paragraph or 5-6 bullet points
Binary Neutron Stars
Compare the gravitational wave luminosity of a neutron star-neutron star
binary in a circular orbit of 50km separation with the electromagnetic
luminosity of the system if one star has a temperature of 105K and the
other has a temperature of 106K.
Accreting black hole binary
A 10 solar mass black hole increases its mass by 0.1Msun over 10 years by
accretion from a 20Msun O supergiant in a 1 year circular orbit. How much
gravitational potential energy has been lost. If about the same amount of
energy is radiated from the system through an accretiondisk anf jet, make
an order of magnitude estimate of its average electromagnetic luminosity in
Watts. (this is a simple question requiring careful handling of big numbers
and simple physics)
Literature review: Find a recent letter on gamma ray bursts and
write a 1 page review. Please Include a copy of the letter you
reviewed to assist in marking.