ASTR 640 Homework


Note: In general, the homeworks will be posted right after class on the day they are assigned. Prior to that, they are draft versions and may change. Draft versions are are available so you can get an idea of what is coming, but make sure to check for the real version of the homework.


March 18:
Reading Assignments:
- Peterson Chapter 5 (especially 5.5 and 5.6)
- Conference proceedings by Begelman and by Madejski (handed out in class)
- Keplerian Motion of Broad-Line Region Gas as Evidence for Supermassive Black Holes in Active Galactic Nuclei by Peterson, B.M. & Wandel, A. 1999 ApJ 521, 95
- A very good review: The Masses of Black Holes in Active Galactic Nuclei by B.M. Peterson 2007 in ``The Central Engine of Active Galactic Nuclei'', ASP Conf. Ser. 373, Eds. Luis C. Ho and Jian-Min Wang (arXiv:astro-ph/0703197)
- Active Galactic Nuclei and Quasars, 2010-2020 Science White Paper for the 2009 NRC Decadal Review by Elvis et al.
- If you have not already done so, please examine John Kormendy's "Supermassive Black Holes in Galactic Nuclei" web page.

Mar 13:
For the written homework, please revise your term paper proposals. This must be complete before spring break, and ideally, before the midterm exam on Wed Mar 27.
Regarding the midterm, a sheet of paper with whatever you want written on it will be allowed.

Mar 6:
Reading Assignment:
- ``Possible power source of Seyfert galaxies and QSOs'' J. G. Hills 1975 Nature 254, 295.
- Peterson Ch 4 (you can skip superluminal motion and blazars)
- Peterson Ch 7
- Frank, King & Raine: Ch 5.5 "The Emitted Spectrum"
Written Homework, due March 23:
Homework Problem Set 4 in PostScript [ (in LaTeX).]

Mar 4:
Reading Assignment:
- Peterson: Ch 4 (you can skip superluminal motion and blazars)
- Peterson: Ch 7
- Frank, King & Raine: 5.5 "The Emitted Spectrum"
- And please review Peterson: Ch 3

Feb 27:
* TransitFinder project extend until Monday March 4th. Please focus on quality, not quantity.
* Revised date: Term Paper proposals due Wed March 6th

Feb 16:
- Reading Assignment:
(1) Frank, King & Raine: Ch 7.1 - 7.6
(2) To get an appreciation of what is current cutting-edge research on the galactic center, read the rationale and program for the IAU Symposium #303 (2013 Sep 30) on "The Galactic Center: Feeding and Feedback in a Normal Galactic Nucleus".
(3) Read the background info on Gravitational redshift and White Dwarf stars from the public information site "Einstein OnLine".
(4) Read at least the abstract of the paper: "A new Cepheid Distance the maser-host galaxy NGC 4258 and its implications for the Hubble Constant" by Macri et al. 2006 ApJ 652, 1133.

Written Homework, due Friday March 1:
Submit a 1-page typed Term Paper proposal. It should contain a title, brief description of the content of the paper, and a bibliography of at least 2 sources. (See the links to term paper grading critiera and additional information on the class website).

Feb 6:
Reading assignment:
- Peterson: Ch 8
- Accretion Power: Ch 2.1-2.4.
- ``Infrared Adaptive Optics Reveals Stars Orbiting Within Light-Hours of the Milky Way's Center'' by Bertram Schwarzschild in the 2003 February issue of Physics Today. Though some values need updating, this well-written summary is still very good.
- - Kepler-16: A Transiting Circumbinary Planet, Doyle, L.R., et al. Science, 333, 1602
- - Transiting circumbinary planets Kepler-34 b and Kepler-35 b, Welsh, W.F., et al. Nature, 481, 475
- - The Neptune-sized Circumbinary Planet Kepler-38b, Orosz, J.A., et al. ApJ, 758, 14
And for next week, also read:
- - Kepler-47: A Transiting Circumbinary Multiplanet System, Orosz, J.A., et al. Science, 1511, 337

Written Homework, due Wed Feb 20:
Homework Problem Set 3 in PostScript [ Homework Problem Set 3 in LaTeX ]

Jan 30:
Reading assignment I:
- Chapter 3 in Peterson's book.
- Chapter 1 in Frank, King & Raine's (Accretion Power) book.
- A Geometric Distance to the Galaxy NGC4258 from Orbital Motions in a Nuclear Gas Disk Herrnstein, J.R. et al. 1999 Nature 400, 539.
- Evidence for a black hole from high rotation velocities in a sub-parsec region of NGC4258 Miyoshi, M. et al. 1995 Nature, 373, 127.

Reading assignment II: (please have these read by Feb 11th)
Read the set of the first three discovery papers on transiting circumbinary planets:
- Kepler-16: A Transiting Circumbinary Planet, Doyle, L.R. et al. Science, 333, 1602
- Transiting circumbinary planets Kepler-34 b and Kepler-35 b, Welsh, W.F. et al. Nature, 481, 475
- The Neptune-sized Circumbinary Planet Kepler-38b, Orosz, J.A. et al. ApJ, 758, 14

Written Homework, due Wed Feb 6: Homework Problem Set 2 in PostScript Homework Problem Set 2 in LaTeX

Jan 19:
Reading Homework:
- Read the popular article ``How Black Holes Helped Build the Universe'' by C. Wanjek in the 2007 Jan issue of Sky & Telescope magazine.
- Read Ch 1 and Ch 2 in Peterson's An Introduction to Active Galactic Nuclei.
- Read the article "Monsters at the Heart of Galaxy Formation" by John Kormendy 2000 Science, 289, 1484-1485. (NB: you can get a copy on Astro-ph or from Kormendy's website.)
- Review what is mean by "redshift".

Written Homework, due Wednesday Jan 30:
 Homework Problem Set 1 in PostScript
Homework Problem Set 1 in LaTeX

Note: Next week's written homework requires the following paper:
Miyoshi, M., Moran, J., Herrnstein, J., Greenhill, L., Nakai, N., Diamond, P. & Inoue, M. "Evidence for a black hole from high rotation velocities in a sub-parsec region of NGC 4258" 1995 Nature 373, 127




Homework Philosophy:
 The homework assignments (10% of the course grade) are designed to be relatively easy and broad in scope. They are really a warm-up to get you thinking. Consequently,

  • 1) The goal is not to get the answer. The goal is for you to understand at a fundamental level what is going on. Think: What does the answer mean or imply? What are the consequences? Even if you are not asked to do so, you should always comment on the significance & implications of your answer.

  • 2) As young scientists, you are mature enough to no longer be making "dumb mistakes". There will not be much leniency for errors of this kind. Always check your work to make sure it makes sense.

  • 3) Try to do the homework on your own. You can check your answers with your classmates when you're done, but resist working in teams unless you are really stuck. Homework that is nearly identical to another student's will receive no credit.

  • 4) A research astronomer doesn't have someone checking their results, so they have to be confident they have done things 100% correctly. (Well, sometimes a referee of a paper will carefully checks things but they won't check everything.) Just a few errors will erode away the confidence of your colleagues to the point that they can't trust any of your research. Then your career grinds to a halt. Get out of the habit of answering questions as if they were homework questions and into the habit of solving things as if they were research problems. Do your homework such that you are completely confident of your answers/solutions. If you are unsure of anything, then seek help. In theory, I should not have to collect and grade the homework. Rather, we just discuss the topics that folks had difficulty with.

    Each homework is worth 50 points.
    Aim to get 40 points or above on each HW set.

    Late Homework Policy:
    Late homework will incur a penalty as follows:
    - 4 points deducted for 1 day late; 1 point deducted each day thereafter.
    The maximum penalty is 10 points (after 1 week). In other words, there is a floor beyond which no additional loss of points will occur. Even if you are 3 weeks late in doing the assignment, it is much better than not doing it at all. The only exception is if the answer to the homework question is discussed in class, in which case that problem is no longer valid for late credit; late homework earns zero credit for this problem.

    If a student is observing the night before a homework is due, the student can take 1 or 2 extra days to hand in the homework without penalty, ** with advanced permission.**
    If a student is defending their thesis (dissertation or paper) within +/- 2 days a homework is due, the student can get a few extra days to hand in the homework without penalty, ** with advanced permission.**