this program constitutes a new and fundamental exploration of active galactic nuclei (agn) that will yield new understanding of the agn phenomena, new observational tools to reveal obscured agn, and new broad constraints on efforts to model their continuum radiation fields. the goals of this program are to: [a] obtain heavy element abundances in the innermost regions of agn, [b] determine a dynamical zone for agn coronal line regions (clr) relative to seyfert broad (blr) and narrow line regions (nlr), [c] measure the kinetic temperature and density of agn clr, [d] obtain constraints on agn photoionization models that are free of abundance and gas phase depletion assumptions, and [e] obtain a data set that can reveal correlations between these data ([a] through [d]) and nuclear classification. this program will increase the scientific mission return of the central program proposal hsmith_agn beyond its original design by combining gt data with these ot data to achieve new additional goals. our analysis focuses on bright coronal and other forbidden lines. the primary line list (table 1) emphasizes transitions from a maximal set of ionization states of a small group of elements. our approach is to observe multiple transitions within a given ion and among several ions of the same element to constrain clr kinetic temperature and density via infrared lines and independent of assumed abundance ratios. similarly, observing a wide range of ionization states of a single element, will constrain photoionization models independent of assumed gas phase depletion factors, and velocity resolved grating spectra will reveal coronal line profile shapes relative to other blr and nlr lines. finally, our target list (table 2) is designed to test the hypothesis that coronal lines can reveal obscured agn.
Instrument
SWS01 , SWS02
Temporal Coverage
1996-08-02T20:10:04Z/1997-01-18T20:47:18Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the world's first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
