Physics & Astronomy 590
Spring 2018 Homepage
Univ. Louisville
Instructor: Dr.
Gerard Williger, NS 206, tel 852-0821
e-mail: gmwill06@*
where *= louisville.edu (please do not e-mail to my Groupwise acct)
My homepage is here
Office hours: after
class (12:15-1pm Tue/Thu) and by appointment;
*I will not entertain questions on problem sets on the day they are
due*
Lectures: NS 312
and NS313, Tue/Thu 11am-12:15pm
We'll use NS312 (across the hall from NS313, with a computer) for
some lectures. We'll use NS313 for tests.
Text: Foundations of Astrophysics,
Ryden & Peterson, 1st ed., Addison-Wesley (2010)
The course objective is to learn basic the basic physics of
astronomical phenomena. A mastery of calculus
and introductory (calculus-based) college physics is assumed, plus
the material for Astronomy 307.
Differential equations will help, but if you
have not had them, you can pick up what you will need. The
lectures will begin on Tuesday, Jan. 7.
A password-enabled protected
site will contain answers to homework and midterm problems, if
I do not
pass them out in class. I may also put commentaries on common
homework errors there as well.
Finally, all the PowerPoint files for a recent Astro 107 class, plus
animation files,
are on the protected site. They're an excellent overview for
the material in this course, and I
highly recommend your looking at the files. We'll try to cover
roughly chapters 13-24 in our textbook.
GRAPHING CALCULATORS ARE BANNED ON TESTS AND PROBLEMS AT THE
BOARD.
Here are
links for supplemental material and additional explanations
astro-news
for Astro 107 (see for solar plasma ejection article etc.)
Reading/Schedule:
09-11 Jan: Chap 13
16-18 Jan: Chap 13-14
23-25 Jan: Chap 14-15
30 Jan-01 Feb: Chap 15-16 (Quiz 1 on 1 Feb)
06-08 Feb: Chap 16
13-15 Feb: Chap 17
20-22 Feb: Chap 18
27 Feb-01 Mar: Chap 19 (Midterm on 1 Mar)
06-08 Mar: Chap 19-20
20-22 Mar: Chap 20-21
27-29 Mar: Chap 21-22 (Quiz 2 on 29 Mar)
03-05 Apr: Chap 22-23
10-12 Apr: Chap 23-24
17-19 Apr: Chap 24, research, presentations (or presentations moved
to Reading Day or afterward)
Board Problem groups: Gp A:RS ; Gp B:SK-KJ; Gp C:TR-DM; Gp D:JC-VK
Nominal Board Problem dates (subject to change): 30 Jan (Gp C), 20
Feb (extended), 22 Mar (extended), 12 Apr
Presentations should be about 10 minutes talking, 2 minutes of
questions each.
TIME FOR PRESENTATIONS: Tue 1 May, 11:00am, Astronomy seminar room, NS 312
Thu 26 Apr 11:30am-2pm: CUMULATIVE FINAL EXAM.
CHAPTER TOPICS:
13 - magnitudes, stellar luminosities/sizes, binaries, radial
velocity/light curves
14 - stellar atmospheres, Hertzsprung-Russell diagram
15 - stellar interiors, equations of stellar structure
16 - interstellar medium, H II regions
17 - star formation, evolution of solar mass stars, Cepheids/RR
Lyrae stars
18 - white dwarfs, neutron stars, stellar mass black holes,
supernova remnants
19 - Galactic morphology, structure, rotation curve, nucleus
20 - galaxy classification, spectra, supermassive black holes,
Hubble law
21 - active galaxies, accretion disks, quasars, intergalactic medium
22 - galaxy clusters/superclusters, galaxy mergers
23 - cosmology (Newtonian and Einsteinian), spacetime metrics,
Friedmann equation
24 - accelerating Universe, cosmic microwave background, Big Bang,
consensus model
CHALLENGE PROBLEMS: Done on your own. You need to learn
them. I may call students to the board to
do similar problems for participation credit. They add to the
participation grade. You may find your mistakes
for further participation credit. Do this by annotating your
ORIGINAL,
homework which I marked. Use a DIFFERENT COLOR
pen/pencil from the original. Explain what you did wrong in words.
COUNTS PROBLEMS: These are graded homework. You can work
together, but must turn in your
own, original solutions. The average of Counts Problems will
be 5-10% total of your grade.
Any evidence of cheating of any kind will
result in at least a zero for all parties
concerned, and potentially further penalties/sanctions.
YOU
MUST SHOW YOUR WORK (INCLUDING ORIGINS OF ALL NUMBERS)
SO THAT I CAN
FOLLOW YOUR CALCULATIONS AND GIVE PARTIAL CREDIT.
PLEASE STAPLE YOUR HOMEWORK! LOOSE PAGES MAY BE LOST.
HW01: due Tue 16 Jan CHALLENGE: 13.1,13.3,13.4,13.6,13.9,
revisions due 30 Jan
HW02: due Tue 23 Jan CHALLENGE: 13.7,13.8,14.1,14.4, revisions
due 30 Jan
HW03: due Tue 30 Jan CHALLENGE: 14.2,14.5,15.3,15.5,15.6,
revisions due 06 Feb
HW04: due Tue 06 Feb CHALLENGE: 15.4,15.7, revisions due 13
Feb
HW05: due Tue 13 Feb CHALLENGE: 15.9 (extended from
HW04),16.1,16.3,16.6 (hint: use
the center of mass frame and conserve energy),16.7, revisions due 20
Feb
HW06: due Tue 20 Feb CHALLENGE: 16.2,16.4,16.9, 17.1,17.3,17.4,
revisions due 27 Feb
HW07: due Tue 27 Feb CHALLENGE: 17.2,17.5, 18.1,18.2,18.7
HW08: due *THU* 08 Mar CHALLENGE: 18.3,18.5,18.6, 19.1,19.2,19.6
HW09: due Thu 22 Mar (unintentionally extended due to day/date mismatch) CHALLENGE: 19.5,19.8,19.9,19.10,20.1,20.2
HW10: due TUE 27 Mar CHALLENGE, 20.4,20.6,20.7,20.8, 21.1, 21.2
HW11: due TUE 03 Apr CHALLENGE, 21.3,21.4,21.5,21.6,21.7, 22.2
HW12: due TUE 10 Apr CHALLENGE, 22.1,22.3,22.4,22.5,22.6
HW13: due TUE 17 Apr CHALLENGE, 23.1,23.2.23.3.23.4,23.5, 24.1
COUNTS PROBLEMS/EXTRA CREDIT
Any paper
or seminar/talk write-ups should be typed, on paper.
Grammar/spelling/style count.
Keep a backup for yourself. Undergrads do 250-300
words, grad students 500-600 unless
otherwise noted.
COUNTS 1: Summarize Bessell (photometric systems, 2005, ARAA, 43,
293, on protected site).
It's long so I just want parts of it: Beginning/Sec 1-2.3,
5.1-5.3, 6-8. (By the way, Robert F. Wing was my teacher for the
equivalent of Astro 308.)
With this and all paper summaries,
0) Look up and list any definitions you need to learn. If you
need help, ask.
i) your first sentence should be a punchy summary: "This paper
shows/discusses ..."
Then clearly identify at least these points:
ii) the main science question (or questions)
iii) data source description (e.g. telescopes, surveys etc. if
it is an observational paper)
iv) methods
v) results, discussion/conclusions
vi) future work/implications
IMPORTANT: Avoid copying phrases or sentencesverbatim. Put the
material into your own words. Use plural with "data", and
singular with "datum".
Undergrads do 500 words, grad students 750.
Due Tue Jan 23 (extended) at the beginning of class.
COUNTS-2: Color Problem: Compute the Planck function in
wavelength for 4400A, 5500A, 6200A, 7700A for temperatures 3000K,
5000K, 10000K, 20000K. The wavelengths correspond to the
centroids of the B,V,R,I filters respectively, and
the temperatures correspond roughly to M, G, A and B stars.
Using the Planck curves as fluxes (dlambda=1A is fine), compute the
colors in terms of magnitude B-V and R-I in temperature.
Remember that Vega
defines all magnitudes and colors as zero. Why do astronomers
tend to use B-V as a main reference for colors
of spectral types rather than R-I? Due Tue 6 Feb (EXTENDED 2x), at
the beginning of class.
COUNTS-3: due Tue 13 Feb (EXTENDED). CONTACT DR. HABERZETTL
(lghabe01@*, tel x1986) immediately
to get an account on the department's student computers if your Java simulator
does not run on the website below.
Radial Velocity Pblm:
(A) Use the Terzian-Herter radial velocity calculator from Cornell
U. linked here
for this problem. Your job:
EXPLORE PARAMETER SPACE TO FIND OUT HOW RADIAL VELOCITY VARIES
WITH VARIOUS PARAMETERS.
TEST OUT A GRID OF VALUES FOR EACH PARAMETER.
VARY THE PARAMETERS ONE BY ONE, SYSTEMATICALLY FROM LOW TO HIGH
VALUES.
START WITH THE DEFAULT VALUES AND EXPLORE THE
POSSIBILITIES.
THEN, REPORT ON THE EFFECTS ON THE RADIAL VELOCITY CURVE.
Use 5 system parameters:
1) mass ratio (default: 1:1)
2) semi-major axis a (default: 1 AU)
3) eccentricity e (default: e=0)
4) inclination i (default: i=90 deg)
5) angle to line of apsides w (default: w=0)
Observe these characteristics of radial velocity curve:
a) maximum radial velocity v_r
b) ratio of v_{r,1}/v_{r,2}
c) period P
d) RELATIVE FWHM (to period) of maximum, minimum v_r (as a
function of time and as a fraction of total period) for a given
star. If you do not know the concept of FWHM well, ask me.
e) symmetry of v_r curve at maximum (for v_r>0); then consider
separately the symmetry around minimum v_r (for v_r<0) for a
given star
f) time from v_{r,max} to v_{r,min} compared to v_{r,min} to
v_{r,max} for a given star
g) does v_{r,max}=-v_{r,min} for a given star?
How does each system parameter affect each observable? Some system
parameters will affect more observables than others.
Examine the radial velocity curves in a "grid", varying the
parameters
systematically.
Make 5x7 table for presentation, so each parameter-observable
combination has some description.
I will provide you with a blank grid template by 25 Jan.
(Please remind me if I do not get this to you.)
Be sure to test the elliptical case (e>0) as well as the
circular case (e=0) whenever you can!
COUNTS-4: due Thu 22 Feb (extended). This is a TEAM assignment,
with one write-up per
board problem team.
You should classify 3 stars each, using the printed spectra to be
handed out:
BS: TBA
SK, KJ: TBA
VK-JC: TBA
TR-DM: TBA
Go onto ADS and find Jacoby, Hunter and Christian (1984), ApJS,
56, 257 or download 1984ApJS...56..257J for reference spectra.
1 pt - 1) Give the order from hottest to coldest for your 3
spectra.
2 pts- 2) Measure the peak wavelength, and calculate a temperature
based on Wien's Law
4 pts- 3) Classify each spectrum by spectral type/subtype e.g. A1,
F7, G9
etc. Compare the corresponding temperature
based on absorption
lines and spectral shape (from the textbook
appendices or other
reputable source) with the answer in (1).
In particular, compare the flux level at 3500A and the peak for
your star
vs. the template stars. Comment on your results.
NOTE: Include a printout of the plot of your
star and the closest
template star, indicating which lines/features
you used to classify your star.
3 pts - 4) Classify each spectrum by luminosity class: V
(main sequence), IV (subgiant), III (giant), II (bright giant), I
(supergiant)
Give justification for your classifications, in terms of narrow
lines, broad lines, flux peak, slope or any other features you
see.
Common lines (in Angstroms) are:
TiO bands in the red (very broad)
H-alpha 6563
NaI doublet at 5896 (may not be resolved)
FeI 5270 (solar spectrum)
H-beta 4863
H-gamma 4342
H-delta 4103 (calculate higher order lines yourself or look
them up, as needed - they sometimes are visible)
CaII H,K lines at 3935,3970
Balmer break 3646
You can find more information at http://skyserver.sdss.org/dr1/en/proj/advanced/spectraltypes/lines.asp#spectab
You can find a GREAT online tool via the WKU
Astro 106 online spectral calculator
Another resource: Columbia
U solar spectral exercise (includes description of A-K lines
from 19th century)
You are free to look up any other stellar spectral catalogue, list
of lines etc.
CITE YOUR REFERENCES.
COUNTS-5: due Thu 8 Mar (extended): Summarize Ridley et al. (2013), MNRAS,
433, 138, in 300 words / 1 page. Grammar, spelling and style
count.
COUNTS-6: due Tue 20 Mar: Summarize Chakrabarti et al. (2015),
ApJ, 802, L4, in 300 words /
1 page, as for other articles.
COUNTS-7: due Tue 27 Mar: Summarize Davis et al. (2015), ApJ, 802,
L13 in 300 words / 1 page.
COUNTS-8: due Tue 10 Apr: Summarize Strazullo et al. (2015),
A& A, 576, L6, in 300 words / 1 page.
(We may also add one or more papers related to Chapters 21, 23
or 24.)
EXTRA CREDIT:
TBA
PRESENTATIONS:
We'll do presentations on Tue 1 May at 11am in Nat Sci 312, worth 7.5% of your grade.
Here are the rules.
1) topics+proposed papers due Tue 24 Apr
2) maximum 6 minutes+2 minutes questions, strictly enforced, SLIDES
DUE (POWERPOINT OR PDF) TBA
3) I recommend about 7-10 slides
4) explain a-the scientific question, b-background, c-the
methods/data, d-what is new (the discovery/result), e-the meaning
for the big picture/science and future work
5) Your audience is your classmates. They should understand what you
do. If they don't, you haven't done your job to explain it to them.
6) You're encouraged to get graphics from other articles, Wikipedia
etc. BUT CITE your sources!
7) Use a REFEREED journal article, 6 pages maximum, on any subject
in Astro 307 or 590. The more recent, the better. Try to stay with one
published in the last few years, to keep technology and science current for the class.
You are encouraged to read other papers for
background material, and these can be longer, but your primary one
should be short. Review papers on anything (as they tend to be long
and not have a science question), general relativity, modified
gravity and quantum gravity in particular are NOT allowed. The
standard journal search engine is
ADS.
I will introduce its use in class.
8) There is a STRICT upper size limit of 6 pages (4-5 pages
preferred) in any journal. No exceptions. Remember, these talks are
SHORT.
9) I recommend getting an article from the following. Try especially
the Letters from each journal.
Nature
Astrophysical Journal
Astrophysical Journal
Letters
Monthly Notices of the
Royal Astronomical Society
Monthly Notices of the
Royal Astronomical Society - Letters
Astronomical Journal
Astronomy & Astrophysics
(especially Letters)
Publications of
the Astronomical Society of the Pacific
Icarus (solar
system journal)
Publications of the Astronomical
Society of Japan
If you wish to present a paper summary from another journal, please
clear it in advance with G. Williger.
Other refereed journals are available via the NASA ADS
site, and
arXiv preprint server (look for PASJ
articles or other hard to find articles here) site.
10) WRITEUP:
You will also need to do a 350 words/one page (for
undergrads) or 600-700 words/two page (for grad students)
writeup of your paper:
a) science question
b) observations/data sample (if observational) or methods
(if theoretical)
c) results
d) conclusions
e) further work
This is due typed, on paper, when you make your
presentation. You may include background material from
other papers.
Cite liberally.
SCHEDULED/APPROVED PRESENTATIONS:
Participation grades are subjective and are subject
to change. They result from
a combination of class participation (comments and
questions) plus performance at any problems done at the board in
class, or assisting other
students doing so. If you never say anything or skip class (which I can note in any way,
including not picking
up homework) then you can get as little as zero. I also am
less
likely to be generous with
participation if you habitually don't
turn in any written, assigned
homework, since doing homework generates questions
and feedback on common
misconceptions.
GRADING:
After class discussion on 10 Jan,
your grades are composed of
1 midterm (22.5%)
2 quizzes (5% each)
comprehensive final (40%)
avg of 2 board problems (5%, changing teams)
presentation (7.5%)
participation+homework (15%).
Details are on the syllabus.
*IF YOU ARE NOT IN CLASS WHEN I CALL YOU TO THE BOARD, AND YOU DO
NOT
HAVE A VERIFIABLE EXCUSE, THE PART OF YOUR PARTICIPATION GRADE
FROM THE
BOARD PROBLEM MAY BE ZERO.*
The presentation will involve summarizing a paper from the
literature.
Partial
Credit:
Homework and tests will have
partial credit available. You MUST show
your work, in particular the
equations which are used to begin a
calculation, to get any credit at
all. You must keep track of significant
digits. If the least
accurate number going into a calculation has n
significant digits, then the
answer should have that number, also.
If you happen to do the wrong
homework problem instead of an assigned
one, you will typically not get
credit for it. Leaving a question
blank definitely earns a zero.
On homework, I also count it as a sign of lack of
participation.
Scientists
need
to check their own work. To this end,
you are expected to have an
idea what a reasonable answer is, even though
you might not get the
correct answer.
A
reasonable answer has the correct units -- use dimensional analysis!
It also has an order of
magnitude
which is not wildly
inconsistent with information given in the problem or common
knowledge. For
example, calculating a core temperature of the Sun to
be 3K is a nonsense
(unreasonable) answer, because its surface and even
Earth are much hotter than
that. If your answer is way off
and you
note it and attempt to explain where the problem might be,
I will take it into
consideration.
If
you give a nonsense answer due to simple arithmetic or
mathematical
errors and do not catch it,
you may not get partial credit for setting up the
problem correctly.
Here are also links (from
an Astronomy 107 links site) for recent
discoveries,
(simple) equations
used in that class
and supplemental
material.
Planned material to cover (subject to
modification; links for supplemental material are
provided):
orbital mechanics, Earth-Moon system, tides, nature of
light, telescopes/detectors, our solar system and others
We will begin stellar astrophysics if time permits.
Topics
covered:
stars, stellar structure,
interstellar medium, star formation, the Milky Way,
galaxies, cosmology
Additional
material from other chapters and books will be added as
needed.
If you miss a test and you give
me a week's
advance notice with a
documentable reason, the make-up may be a one hour
oral exam.
General test policy is that
once you leave the room, you can't come back in.
You are permitted to help
each other in groups, but you must turn in your own work.
Grading will be done on a
curve.
There is no fixed
percentile for grades, nor any absolute standard for letter
grades. The plus-minus
grading system (A, A-, B+ etc.) will be used.