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Continuum Fitting HST QSO SpectraThe Principal Component Analysis (PCA) method which we are using to fit and describe QSO spectra relies upon the fact that QSO continuum are generally very smooth and simple except for emission and absorption lines. To see this we need high signal-to-noise (S/N) spectra of QSOs at low redshift which have relatively few absorption lines in the Lyman-a forest. We need a large number of such spectra to use as the basis set for the PCA analysis which will find the set of principal component spectra which describe the QSO family as a whole. We have found that too few HST spectra have the required S/N and hence we need to supplement them with ground based spectra of QSOs at higher redshift. We have many such spectra and we have been working to make them suitable for this analysis. We have concentrated on this topic since 12/15/01.
Document ID
20020039047
Acquisition Source
Goddard Space Flight Center
Document Type
Contractor or Grantee Report
Authors
Tytler, David (California Univ. San Diego, CA United States)
Oliversen, Ronald J.
Date Acquired
September 7, 2013
Publication Date
March 1, 2002
Subject Category
Astrophysics
Report/Patent Number
NRA-99-0-LTSA-072
Funding Number(s)
CONTRACT_GRANT: NAG5-9224
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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