1. 1a.
Read the week 6 instructor notes for a discussion of
different distance measuring methods (including the term 'standard
candle') in astronomy.
1b. For images (& explanations) of
what the Milky Way galaxy looks like in a wide variety of wavelength of light,
go to the following list of images.
1c. For an
early 2002 report of a newly discovered hot, thin corona surrounding our Milky
Way Galaxy, click on this link: http://fuse.pha.jhu.edu/wpb/sci_HVC.html
1d.
For a very nice quick-time movie of a simulated future collision and merger
between our Milky Way galaxy with the the Andromeda galaxy, go to the following
link:
http://www.galaxydynamics.org/spiralmetamorphosis.html (turn on your speakers)
And here's
another very nice simulation, set to music (turn on your speakers), of two
galaxies merging:
http://www.galaxydynamics.org/galaxiesincollision.html
These
simulations are among many you can find at: http://www.galaxydynamics.org/
1e.
For an excellent, easy-to-read review of what research astronomers think about
the formation and evolution of galaxies (including their supermassive black
holes, their stars, and their dark matter), go to the following websites:
http://www.space.com/scienceastronomy/blackhole_history_030128-1.html
http://www.brightsurf.com/news/june_04/EDU_news_060904_c.php
Also
pertinent to galaxy evolution is the latest information about the rate of star
formation in the past. For a summary, see the following link: http://skyandtelescope.com/news/article_1235_1.asp
1f.
For some links to information about galaxy evolution, including mergers and dark
matter considerations, go to the following week 6 galaxy
evolution supplement.
1g. For a summary of recent extremely strong
evidence supporting the hypothesis of a central supermassive black hole at the
center of the Milky Way Galaxy, go to the following URLs:
http://www.eso.org/outreach/press-rel/pr-2002/pr-17-02.html
http://antwrp.gsfc.nasa.gov/apod/ap021018.html
http://chandra.harvard.edu/press/01_releases/press_090501flare.html
1h.
The APOD story on February 12, 2004 is about discovery of a surviving companion
star to a massive star whose core collapsed, leading to explosion of the massive
star. In the 250 years before the explosion, the massive star transferred 10
solar mass to the survivor. The explosion, which occurred in 1993 in the spiral
galaxy M81 (in Ursa Major, about 12 million l.y. distant), has been well-known
for the lack of hydrogen lines in the debris spectrum; yet, it was not a type Ia
supernova. Now we know why. Astronomers also had pre-existing images of the
massive star before explosion, which makes this supernova only the second (after
SN1987a) case in which images exist of a star before
it exploded. For the complete story, see the following URL:
http://hubble.esa.int/science-e/www/object/index.cfm?fobjectid=34455
or,
for the apod short story: http://antwrp.gsfc.nasa.gov/apod/ap040212.html
1j. This link takes you to a story of the relatively recent (1994)
discovery of the closest galaxy to our Milky Way (until someone discovers
another dwarf galaxy even closer?) - the Canis Major galaxy. http://antwrp.gsfc.nasa.gov/apod/ap071104.html
1k.
Here's a report (June 2008) on recent studies of our Milky Way galaxy, based on
long-wavelength studies of our galaxy over the past several years. Some of the
description of our galaxy is a little different than in present-day
textbooks.
http://antwrp.gsfc.nasa.gov/apod/astropix.html
2.
Respond with written answers to the week 6 discussion
questions. I'll take questions about these during class time. Assess
your responses by comparing with my week 6 DQ responses on this web-site,
as instructed on my responses page. Turn these in the first day of week 7.
3. Print out the week 6 quiz and circle your
answer choice for each question. I'll take questions about these during class
time. Turn these in the first day of week 7.