### CORA: Emission Line Fitting with Maximum Likelihood

Posted:

**Sat Dec 17, 2011 8:05 am**[c]CORA: Emission Line Fitting with Maximum Likelihood[/c][/b]

http://adsabs.harvard.edu/abs/2002AN....323..129N

**Abstract**: CORA analyzes emission line spectra with low count numbers and fits them to a line using the maximum likelihood technique. CORA uses a rigorous application of Poisson statistics. From the assumption of Poissonian noise, the software derives the probability for a model of the emission line spectrum to represent the measured spectrum. The likelihood function is used as a criterion for optimizing the parameters of the theoretical spectrum and a fixed point equation is derived allowing an efficient way to obtain line fluxes. CORA has been applied to an X-ray spectrum with the Low Energy Transmission Grating Spectrometer (LETGS) on board the Chandra observatory.**Credit**: Ness, Jan-Uwe; Wichmann, Rainer**Site**: http://januweness.eu/Cora/http://adsabs.harvard.edu/abs/2002AN....323..129N

**Bibcode**: 2011ascl.soft12012N**Preferred citation method**: http://adsabs.harvard.edu/abs/2002AN....323..129N**ID**: ascl:1112.012