... Previous: Substepping and its Application to HST Imaging . ... This is a preliminary report on an application of the co-addition technique based upon the Richardson-Lucy algorithm. The combination of high signal-to-noise ground-based images obtained with the ESO NTT using SUSI with high angular resolution HST FOC f/96 images gives new insights on the properties of galaxy cores and their potential time variability. Cores of galaxies are one of the main thrusts of present extragalactic research. ...

... adass@eso.org . ... c/o Britt Sj?berg . ST-ECF/ESO . ... European Southern Observatory . ... The ADASS '97 Program Organizing Committee is comprised of the following members: Rudi Albrecht (ST-ECF/ESO), Roger Brissenden (SAO), Tim Cornwell (NRAO), R. Crutcher (Uni. of Illinois), F. Rick Harnden - Chair (SAO), George Jacoby (NOAO), Jonathan McDowell (SAO), Jan Noordam (NFRA), Dick Shaw (STScI), Richard Simon (NRAO), Britt Sj?berg (ST-ECF), Doug Tody (NOAO), and Dave Van Buren (IPAC). ...

IRAF/STECF 2-D spectrum point source / background decomposition package . ... The general problem is one of spectral decomposition - of separating the spectra of the point sources from the background. ... The STECF IRAF layered package "specres" provides two tasks to extract point source spectra from 2-D images (either longslit, multislit or cross-dispersed) and decompose the full background over the image. ... A Point Source Function spectrum image is required as a 2-D spectrum. ...