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Spectral Energy Distribution Fitting of Lyman Alpha Emitters:. The optimal method ?. Measuring the age of a galaxy (z=0). plot by Kevin Schawinski. Measuring the age of a galaxy (z=3). plot by Kevin Schawinski.
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Spectral Energy Distribution Fitting of Lyman Alpha Emitters: The optimal method ?
Measuring the age of a galaxy (z=0) plot by Kevin Schawinski
Measuring the age of a galaxy (z=3) plot by Kevin Schawinski
The Ultimate Compilation of LAE SED Fitting Results through Oct. 2008 (courtesy of Kim Nilsson) Does anyone believe any of these results? Except your own? Are you sure that you believe your own SED fitting? Been drinking a lot of Kool-Aid?
14 SED Fitting Choices • Stellar Population Models (BC03 vs. M05 vs. CB07) • Number of stellar populations • IMF • Metallicity range • Single Stellar Population (SSP) vs. Constant Star Formation (CFS) vs. τ model (SFR(t) = SFR(0) exp(-t\τ) ) • Minimum age (maximum age should be age of the universe) • Dust Law (Calzetti vs. SMC vs. Milky Way) • IGM Absorption (Madau for continuum, ? for Ly α) • Individual SEDs or stacked (subsets)? • Include H α? (and other nebular emission lines) • How to handle Ly α? (include in models vs. correct fluxes vs. ignore photometry vs. inflate error bar) • Treatment of photometric uncertainties (bootstrap for stack, non-detections treated the same as detections in fitting?) • Best-fit model determined by? (Brute-force likelihood vs. MCMC) • Parameter uncertainties determined by? (Marginalization vs. Monte Carlo)
Stacked SEDs of IRAC-detected and IRAC-undetected LAEs(Lai et al 2008, ApJ 674, 70)
Two-population fit to stacked SED of IRAC-undetected LAEs(Gawiser et al 2007, ApJ 671, 278)