Astronomy 61: Current Problems in Astronomy and Astrophysics
Prof. David Cohen
Friday 11:30 to 12:20
SC 113 (seminar room)
We'll have class as usual this week at 11:30 on Friday.
Your classmate, Peter Weck, will be giving his thesis talk this Friday at 12:30, right after class, in SC 199. Please come out and support him.
You each have new data to work with – one star each, for now. The data archives are posted; make sure you have yours. The spreadsheet I sent out on Monday is available here. The sample stars were chosen from Naze et al. 2011, from information in Tables 2 and 3. I've collected the relevant information on my annotated version of Table 2 (and put the most relevant info into the spreadsheet).
By Tuesday night, you should download your data and look at it in xspec. You should fit a sequence of models to the data (apec; apec*tbabs; apec*windtabs*tbabs). The tbabs column density should be frozen at the interstellar value (see the spreadsheet). You should send your initial fitting results to David by Tuesday night.
We should probably read and discuss this paper I wrote last year on mass-loss rates of O star winds via X-ray absorption (showing among other things that mass-loss rates are systematically lower than theory predicts). But as of now, I'm going to hold off assigning it.
class information (posted before the semester)
New: David's plots and fit results, posted
General astro research information
Astrobetter – lots of useful information about the nitty-gritty of astronomical research and many aspects of being an astronomy student and astronomer
Astrobites – very short summaries of interesting research papers, written for undergraduates by graduate students.
This page is maintained by David Cohen
cohen -at- astro.swarthmore.edu
Last modified: April 21, 2015