Thursday, June 16, 2005

I had an idea! [warning science]

the following post is an explanation of an idea I had for my doc degree, it is a very scientific post and basicly I am only posting it to get feedback from apelleri and to enlightened you on my genius (or lack of).

Basicaly it is an idea that would allow me to get more information on my galaxy using long slit spectroscopy at the Megantic space telescope (j/k, the megantic telescope). I stared with the following premisse, from my OASIS data I have reconstructed integrated spectrum of the central region of my galaxies. So I know how each lenslet contribute to the flux of the integrated spectrum with a relatively high precission. At Megantic I can obtain integrated spectrum that would overlap the spectrum I already have but show other wavelength where I don't have information. Now I think that I should be able to divide the flux of the wavelength I don't know about into the individual spectra of OASIS knowing how they contribute to the integrated spectrum. This would give me a way to "calculate" approximately parameters that I had no information about before. It wouldn't be perfect but it would be better then no information. I would make sure that the slit of Megantic spectrometer covers just about the right regions (to lower the possible error), wich according to the galaxies' pictures we have should be possible.

If apelleri and my thesis director convince me that is a bad idea, at worse we know that some area dominate the integrated spectrum we can suppose that they come from those dominating region and at least have information about them. So apelleri give me your honest opinion. You know me I always want true opinion.

1 comment:

apelleri said...

Hi Asaathi,
I agree that if you know the flux level of each lenslet for some wavelength ranges (MR1 and MR2), you can fairly extrapolate the flux at other wavelengths from an integrated spectra if you stay within the visible range. However, I don't think it is necessarely the case with the spectral line strengths and line profiles. The flux level is usually dominated by a very small number of the most massive stars (and the nebular emission they produce if massive enough), while the line profiles are shaped by a more numerous amount of stars (See e.g. Bruhweiler et al. 2003, AJ, 125, 3082 in the UV). And sometimes, some line profiles are barely related to the flux dominating stars. My question now is how will you extrapolate the information on line profiles and EW related to each lenslet from the integrated spectrum and flux information? Even if you know the line profile of some lines for each lenslet, I think it will be hard to extrapolate the information for other lines, unless they are related (as Halpha, Hbeta, etc.). Or maybe I missed something...

Keep in touch,
apelleri