Thursday, January 27, 2011

Shen et al. 2010 DR7 mass estimates vs 2008 DR3

at last I could read the fits table in Matlab. It seems that it works well.

Next step is read the 2008 data and cross-list them with 2010. here is a plot of log BH masses from Shen 2008 (76990 objects) crosslisted with Shen 2010

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I was looking for a possible clockwise rotation in the above plot. If there was a clockwise rotation that could be interpreted that the new mass estimates using two Gaussian to fit the emission lines has resolved the difference between sigma_line and fwhm.

There is no such rotation in this plot that means using one Gaussian or two Gaussian doesn't change anything. The main source of the difference is non-Gaussianity of the lines.

Just to be sure that I am comparing same objects from both data sample I have plotted some other quantities like redshift, Lbol and at last MJD,PLate,Fiber. So there is no problem with the crosslisting.

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Surprisingly their measured Lbol is different now.

 

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TO DO NEXT:

about catalogue paper, I need a to have an object with low S/N ratio to see the effect of the PCA. which means before PCA we estimate larger sigma but after PCA sigma is smaller.

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