Aspen 2010: black magic with SN Ia light curves

(NB:  While I will often be writing about science at a level appropriate for the general interested reader, I may just as often write about science at a level which assumes some familiarity, particularly with physics and/or astronomy.  I’m going to label these cases with the tag “technical”, so that you can skip them — or seek them out! — as your interests permit.  Questions always welcome in the comments section, of course.)

Well, the week is blowing by and there’s been no shortage of stimulation.  Food, drink, sun, cheer, magic (at the bar), cycling, beach volleyball, trying to keep score for beach volleyball, and of course lots of science.  Usually when I get back in the evenings I’m too wiped to blog it all, but I don’t necessarily see that as a bad thing.  Aspen isn’t really the venue at which to announce exciting new results, or work through a brown-bag lunch in planning meetings for the next enormous sky survey; it’s as much recreational and inspirational as it is about work.  And I’m pretty wiped even now.  But here are some parts that stood out in my mind.

I met my new boss, Brian Schmidt, on Monday evening and we’ve chatted a little bit about the kind of things I’m going to be doing on the Skymapper survey.  We had both agreed that I would have a lot of latitude in what I worked on, but it sounds like I have more latitude even than I expected — as long as I publish a ton of papers that use Skymapper data.  My own concept certainly included studies of peculiar SNe Ia and of peculiar supernovae of other types (particularly the overluminous ones, like pair-instability supernovae), and multiwavelength studies of AGN variability.  But it also includes other types of studies, such as the use of SNe Ia to map large-scale velocity flows in the universe, which either weren’t on my radar or which I had previously assumed were firmly off-limits.  While there are other people working on the survey and some appropriate boundaries between interests exist or will have to be negotiated as the need arises, it looks like my own imagination, time and energy are going to be the main limiting factors in what I accomplish.

I had some “useful discussions” (as I might acknowledge them in the paper I’m writing) with esteemed experts in the field which pointed me, for example, to this interesting paper:  about the use of the light curve (brightness vs. time, potentially in several different color filters) of a SN Ia to infer things about the progenitor system, such as the central density of the white dwarf that exploded to form the SN and the original mass of that white dwarf when it started its life as a newly formed “main sequence” star.  These are questions which the data simply haven’t been accurate enough to answer before now, and they are questions of vital importance for anyone who wants to use SNe Ia to study dark energy.  How confident are we that we know the intrinsic luminosity of events hundreds of millions of light years away, when we don’t even know exactly what kind of star exploded?  The technique is incredibly clever and I may have to digest it for a while, but I anticipate finding out lots of cool new things in the process.

Tomorrow I’ve been asked to give a 10-minute talk on some of the things I’ve been working on, as part of a larger session on SN Ia progenitors.  I’m a little bit nervous since there will be people in the audience (some of them quite opinionated) who know a lot more than I do about supernova physics, but hopefully they will heckle me only gently and the things I learn from the discussion will be well worth any risk of embarrassment.


About Richard

I'm an American scientist who is building a new life in Australia. This space will contain words about science and math, but also philosophy, policy, literature, my travels, occasional rants, all sorts of things I find strange and awesome. The views expressed in this blog do not necessarily reflect the opinions of my employer at the time (currently University of Sydney), though personally, I think they should.
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