tag:blogger.com,1999:blog-10448119.post4629879807956996083..comments2024-03-23T06:42:53.608-04:00Comments on Hogg's Research: priors on quasar spectraHogghttp://www.blogger.com/profile/18398397408280534592noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-10448119.post-78720877274836407262010-10-15T21:51:35.278-04:002010-10-15T21:51:35.278-04:00Hi David,
This would be interesting from a physic...Hi David,<br /><br />This would be interesting from a physical perspective as well. Quasar practitioners know that there is a hierarchy of lines that deliver deliver better redshifts than others. For example, high ionization lines like CIV come from near the black hole and can trace outflows and/or winds that result in line assymetries and or self-absorption. Both result in poor redshifts. Balmer lines and low ionization lines tend to come from further out, and so are better tracers of the systemic frame. Low ionization lines are collisionally de-excited in the BLR, and hence are the best tracers of systemic. However, and information theory approach might figure out to best weight the various pieces of information, i.e. all of these line shifts are correlated and the hope is that our modes somehow understand those correlations, but my feeling is that our modes are not as smart as they could be. We are only demanding a good fit, but we have not rewarded or penalized for accuracy about the thing we are most interested in, i.e. the redshift. Maybe you could send us some background on MOPED?Anonymoushttps://www.blogger.com/profile/16119289934459945106noreply@blogger.com