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Unformatted text preview: can make the disks look quite different. One initial attempt at a near-IR Hubble diagram was done using 2MASS images (rather shallow in surface-brightness sensitivity) by Jarrett (2000, PASP 112, 1008). Once again, note that all these exercises can in principle be done in any passband. It's common to use differences in disk scale length at various wavelengths to measure age, metallicity, or extinction gradients (depending on the passbands and one's level of understanding of the system). Ryder & Dopita (1994 ApJ 430, 142) applied it to compare the distributions of current star formation (from azimuthally averaged H-alpha images) to the integral of past star formation (from optical continuum images), to test whether gas is being depleted by star formation uniformly or from the outside inward (they come down on a remarkably uniform behavior, by the way)....
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This note was uploaded on 11/10/2011 for the course AST AST1002 taught by Professor Emilyhoward during the Fall '10 term at Broward College.
- Fall '10