Digitized First Byurakan Survey - DFBS

 

 

 

 

 

 

 

 First Byurakan Survey  

·                            Technical data

·                            FBS zones statistics

·                            Markarian galaxies

·                            FBS based projects

·                            Publications

·                            B.E.Markarian

 DFBS

·                            About DFBS

·                            Institutes

·                            Collaborators

·                            Digitization

·                            Extraction

·                            Download

·                            Sample spectra

·                            Data visualization

·                            Science with DFBS

·                            Publications

·                            DFBS at Roma

Virtual Observatories

·                            Armenian VO

·                            IVOA

·                            Euro-VO

·                            AstroGrid

·                            Grid

 Other related links

·                            Armenian Astronomy

·                            Byurakan Observatory

·                            WFPDB

·                            PDPP

·                            SCAN-IT

 

 DFBS: EXTRACTION OF SPECTRA

The identification of the objects present on the plate and the extraction of their spectra is presently made by us with a catalogue-driven procedure, written by Prof. R. Nesci as an IRAF script, including two simple FORTRAN programs for format conversion and checks.

·         First, a list of all the objects present in the USNO-A2 catalogue down to the plate limit and included in sky area covered by a given plate is converted into pixel coordinates with the IRAF task cctran.

·         Then an image section of 21x150 pixels including one well exposed star is selected and the spectrum is extracted with IRAF/apall in interactive mode (the typical FWHM of a spectrum is 5 pixels and the length 106). This process allows derive the orientation of the spectra on the plate and defines the template for subsequent automatic extractions.

·         Finally all the spectra of the list are extracted automatically by apall, assuming as sky value the mode of an area 21x150 pixel centered on each spectrum.

 

 

 

For further info and use of the DFBS contact Dr. Areg Mickaelian

©2002-2004 Digitized First Byurakan Survey