From king@hubble.IFA.Hawaii.Edu Fri Jun 18 20:06:52 1993 Return-Path: Received: from hale.IFA.Hawaii.Edu by isass6.solar.isas.ac.jp (4.1/SMI-4.1) id AA12214; Fri, 18 Jun 93 20:06:48 JST Received: from akala.IfA.Hawaii.EDU by hale.IFA.Hawaii.Edu (4.1/hale1.1) id AA18242; Fri, 18 Jun 93 01:06:24 HST Received: from hubble.ifa.hawaii.edu.ifa.hawaii.edu by akala.IfA.Hawaii.EDU (4.1/SMI-4.1) id AA02076; Fri, 18 Jun 93 01:06:18 HST Received: by hubble.ifa.hawaii.edu.ifa.hawaii.edu (4.1/SMI-4.1) id AA21932; Fri, 18 Jun 93 01:06:11 HST Date: Fri, 18 Jun 93 01:06:11 HST From: king@hubble.IFA.Hawaii.Edu (Jeremy King) Message-Id: <9306181106.AA21932@hubble.ifa.hawaii.edu.ifa.hawaii.edu> To: labonte@akala.IFA.Hawaii.Edu Subject: MEES' scattered light Cc: mickey@ahinahina.IFA.Hawaii.Edu Status: RO Hi Barry, I've finished up all the reductions for this solar O, NLTE-LTE business and am writing the paper. I've got a final number for the scattered light contribution in the MEES coude spectrograph. I'm convinced that the difference between mine and Altrock's data is due in large part to scattered light (though I believe his values may be a tad on the high side). Using the data of the A-band I found a final value for the scattered light of 4.7% using the Kurucz atlas continuum normalization and the identical value of 4.7% using the observed continuum in the MEES data just to the blue of the A-band. An upper limit comes from making the conservative (but certainly very poor!) assumption that the peaks in between the bands are true continuum-- this value is <6.7%. These values are all at disk center. Recall there's no direct measurements at other disk positions-- but one could make estimates by comparing the MEES data and the Altrock data as a function of mu. In sum though, the scattered light does decline in going to the limb, essentially reaching zero by 0.25-0.3. I don't know what the situation is at Halpha. But I assume in going from the Halpha setup to our setup at 7770 Ang we opened up the slit some, so perhaps it's not as bad at Halpha. Anyway, not as low as we had originally hoped I guess....in any case, I thought you and Don Mickey might be interested. jeremy