syllabus
& course
expectations
safety,
tardy, classroom computer use, and honesty
Astronomy
Picture of the Day
the
latest astrophysics discoveries
what's up in the sky
this week
| Monday, May 24 |
May 25 |
May 26 |
May 27 |
May 28 |
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fake
Memorial Day holiday no classes |
final exams
begin |
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(always done before class) |
29(4,5) back in time to the first few seconds |
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things you should know the answer to before coming to class |
(see
figure 29-8): when did nucleosynthesis start? why didn't it start earlier? when did nucleosynthesis end? why did it end then? why does the n line (blue) continue to change with time, whereas all the curves hav flat-lined? |
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homework (written assignments to be turned in) |
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Hubble
finds star
eating its planet Stellar shrapnel in LMC Herschel resolves the cosmic infrared fog |
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today
is one of those progress days: have you made an appointment with me? |
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of the week |
| Monday, May 17 |
May 18 |
May 19 |
May 20 |
May 21 |
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jit postponed |
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(always done before class) |
new
articles on gamma ray bursts, quasars, and supernovae all on moodle! Major Galaxy Mergers and the Growth of Supermassive Black Holes (a challenging article: try to get the gist of their model and whether observations support it) Gamma Ray Burst Engine Finallly Revealed (a short easy-to-read article) Overluminous Supernovae Push the Chandrasekhar Limit (from this month's Physics Today... what's the point of this article?) |
just posted!: New York Times reporting: Physicists Find Clue to Explain Human Existencein the middle of the NYT article is a link to the posting of the actual article....of peripheral interest: one of the (many) co-authors is S. Snyder, NCSSM class of '85 28(4-5), page 647 (on why the CMB tells us about geometry) 28(8) |
read
about the CMB: at the end of that page is a link to an interactive applet in which you can enter values for H, omega-lambda, omega-matter, omega-baryons, etc etc and see how the CMB anisotropy curve (what we discussed in class yesterday) responds |
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things you should know the answer to before coming to class |
the
questions left from yesterday: what is the final point of the 1st article (the short one)? how do electrons get accelerated, if not by magnetic fields? why were single white dwarfs initially viewed with suspicion as the origin of type IA supernovae? can you summarize the pooint of the last article? why did i assign the 3 articles? what common thread runs through them? _________________ why does the CMB tell us about the geometry of the universe? what decoupled at the "moment of decoupling"? what is the origin of the CMB? in other words, what was it before it was photon energy? |
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homework (written assignments to be turned in) |
did you work on your second project this past weekend? |
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must
see progress on your second project |
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of the week |
heavyweight
star caught running from 30 Dor x-ray discovery points to the location of the dark matter |
| Monday, May 10 |
May 11 |
May 12 |
May 13 |
May 14 |
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(always done before class) |
27(6) how do Seyfert galaxies, BL Lac objects (aka blazars), and QSOs relate? read about the unified model |
27(6) |
gamma
ray burts: even more violent than quasars 27(7) |
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things you should know the answer to before coming to class |
can
you explain how every different type of AGN [Seyfert galaxies 1 and 2,
BL Lac = blazars), QSOs, quasars, radio galaxies] fits into the unified
model? to do this, you must know the properties of each, among other things |
half
of the class to begin work on final project half of class to finishing quasars what does it mean that some regions in the quasar are narrow-line and some are broad line? what do we (the observer) see -- in terms of broad and narrow lines) depending on the angle we look at (into the quasar) plot graphs of the three quantities (d, t, v) that we talked about in class yesterday (as a function of redshift) conclusions? |
know the OBSERVATIONAL properties of the two typesof gamma-ray bursters what are the models that explain each of these types? |
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homework (written assignments to be turned in) |
to
bring to class: dimensional analysis to find the formula for the electron radius (make sure you solve 4 equations in 4 unknowns to show that the solution is unique_ the constant in the Eddington luminosity equation (i think you will miss by a factor of 8; i will explain in class) |
final projects due (lab book or paper copies or electronic files?) have chosen a tentative partner and project for final project |
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of the week |
| Monday, May 3 |
May 4 |
May 5 |
May 6 |
May 7 |
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please
have the courtesy to let me know IN ADVANCE of your absence in class
due to
AP testing |
LAST day in class to work on project with your partner project PRESENTATIONS this THURSDAY |
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your (group's) 1st project PRESENTATION today! plan a 5-7 minute presentation |
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(always done before class) |
review 28(7) as you should now understand the ΩM-ΩΛ diagram much better before friday's class |
27(1-4) |
question 27(35) see questions below |
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re-write your notes from Friday so
that you know how a) GR cosmology is different from Newtonian cosmology b) you understand the steps that led us from the one correction we made to the Newtonian cosmology equations to get the GR equations (see homework below) that sort types of universes by their properties.... know the equations for those lines... what are the OTHER 2 "lines" that we haven't yet discussed |
can
you write down the net force equation that (eventually) produces the
expression for the Eddington limit? suppose that the central energy source producing the light of a quasar was 1 light-hour across.... and suppose that it flickered in luminosity at a rate of 5 times/sec... how would the luminosity change according to an earth observer? the book (problem 35, page 630 ) says that because of the high recessional speed of this quasar, there is time dilation.... well, since we know that the redshift isn't due to recession, but instead to cosmological expansion, is there time dilation due to that? does the mass claimed in the right column of page 622 match that YOU calculated from figure 27-18? is the actual mass? or a lower limit? or an upper limit? |
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homework (written assignments to be turned in) |
to turn in at the beginning of class: a) find a universe (i.e., find its location in the ΩM-ΩΛ diagram) that will expand for an infinite amount of time & have spherical geometry & is decelerating b) find a universe that is accelerating & has spherical geometry (note that both of these universes could not exist in Newtonian cosmology) find another universe that you think has interesting properties finally, what would the two equations for the straight lines in the ΩM-ΩΛ diagram [that we discussed Friday] become (or reduce to) for purely Newtonian cosmologies? |
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| web stuff | M82:
Survivor Black
Holes may be Mid-Sized |
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of the week |
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