Focas-Faint Object Classification And Analysis System

J. F. Jarvis; J. A. Tyson

doi:10.1117/12.957112

3 May 1979 Focas-Faint Object Classification And Analysis System

J. F. Jarvis, J. A. Tyson

Proceedings Volume 0172, Instrumentation in Astronomy III; (1979) https://doi.org/10.1117/12.957112
Event: Instrumentation in Astronomy, 1979, Tucson, United States

Abstract

A system for detecting and classifying images on astronomical plates is described. In particular, the very faint and barely resolved images of 24th magnitude galaxies are shown to be detectable and distinguishable from stellar images of similar brightness. The algorithms and other implementation con-siderations used in the construction of FOCAS are given. Detection and classification at 24th magnitude is achieved with N₂ presensitized IIIaJ plates exposed for one hour in the KPNO 4-m telescope prime focus camera. For a digital 6000x6000 pixel image made from the central square area 37' on a side approximately 16000 objects are found to 24.7 mag on such plates. Since the resulting catalog of objects is 3 or 4 magnitudes deeper than existing surveys a variety of internal tests must be used to assess the accuracy and completeness of the list of objects. The tests and simulations made to support these claims are also discussed.

Citation Download Citation

J. F. Jarvis and J. A. Tyson "Focas-Faint Object Classification And Analysis System", Proc. SPIE 0172, Instrumentation in Astronomy III, (3 May 1979); https://doi.org/10.1117/12.957112

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available