2012-02-10

electromagnetism and massive stars

Inspired in part by our meetings yesterday about Fergus's modeling of imaging data in a coronograph, I worked on a physically motivated re-factor of my physically motivated code to model electromagnetic fields (phase and amplitude) in astronomical telescopes and cameras. I am just a few dozen lines of code away from having a full model (highly approximate) of a simple coronograph.

In the afternoon, Selma de Mink (STScI) gave a nice seminar about extremely massive star evolution. Among many other things, she noted that there is a possibility that low-metallicity, rapidly rotating, massive stars could evolve to very hot temperatures and very high luminosities where no other kinds of stars can be. I think we can find these things in PHAT data on Andromeda; I need to email the team.

3 comments:

  1. Or, you could hope the team has your blog in its RSS! But then the team would say "But David, M31 isn't low-metallicity...."

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  2. I don't think the PHAT team should be wasting its time reading my blog! But if they are, I would point out that there might be chemical inhomogeneities in that huge-ass galaxy.

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  3. Hi Dave, apparently I do waste my time reading your great and unusual blog. Well, since I encountered it last week, doing my homework for this visit. :)

    Good idea to look at the PHAT survey. As mentioned above, it is indeed too metal-rich for this strange evolutionary path as induced by rotation. It is roughly solar metallicity. However, rotation is not the only way to evolve "chemically homogeneously" ... I wonder what is possible with all those wide filters you guys have, crowding will definitely be an issue, will talk to the PHAT people at STScI. - Selma

    A pity I didn't get to talk to you about your eclipsing white dwarfs (post 2012-02-07). Many of those must be so close that they shared a common envelope for a while. Maybe finally some rigorous constraints on common envelope physics? And even better, since this is the intermediate stop to produce a type Ia supernova... If you really work out the underlying population, we could start the population synthesis models that try to predict the rate of Ia's from there. That would skip a lot of uncertainties, and potentially bring us closer to inferring what the progenitors are (wishful optimistic thinking). Any triple eclipses? The ejected envelope provides enough material to form a planet or two in the same plane... (even more wishful thinking).

    - cheers, Selma

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