Astrophysics winter trimester  2009

 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
Tuesday,
May 25
Wednesday,
May 26
Thursday,
May 27
Friday,
May 28
class
fake Memorial Day holiday

no classes



final exams begin
reading
(always done before class)

29(4,5)

back in time to the first few seconds





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?




homework
(written assignments
to be turned in)






web stuff

Hubble finds star eating its planet

Stellar shrapnel in LMC

Herschel resolves the cosmic infrared fog



lab

today is one of those progress days:
have you made an appointment with me?



news/discoveries
of the week






Monday,
May 17
Tuesday,
May 18
Wednesday,
May 19
Thursday,
May 20
Friday,
May 21
class

jit postponed



reading
(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 Existence
in 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



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?




homework
(written assignments
to be turned in)


did you work on your second project this past weekend?




web stuff





lab

must see progress on your second project



news/discoveries
of the week
heavyweight star caught running from 30 Dor

x-ray discovery points to the location of the dark matter





Monday,
May 10
Tuesday,
May 11
Wednesday,
May 12
Thursday,
May 13
Friday,
May 14
class





reading
(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)


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?



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


web stuff





lab





news/discoveries
of the week






Monday,
May 3
Tuesday, 
May 4
Wednesday, 
May 5
Thursday,
May 6
Friday, 
May 7
class
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
jit due by noon today
class starts @ 1:35 pm
your (group's) 1st
project
PRESENTATION
today!

plan a 5-7 minute presentation
reading
(always done
before class)

review 28(7) as you should now understand the ΩMΛ diagram much better before friday's class




 galactic violence:
27(1-4)
27(1-5),
question 27(35)
see questions below
 
things you should know the answer to before coming to class
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?

 

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 ΩMΛ 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
ΩMΛ diagram
[that we discussed Friday] become (or reduce to) for purely

Newtonian cosmologies?






web stuff M82: Survivor Black Holes may be Mid-Sized




lab


 

 


news, discoveries
 of the week



 
 

 
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february pages
january pages

december pages
november pages