SUMMARY OF PROPOSAL 72131

PROFESSOR ANDREW STEPHEN WILSON
WILSON@ASTRO.UMD.EDU

UNIVERSITY OF MARYLAND

COLLEGE PARK
MARYLAND USA 20742
Tel: (301) 405 1519 Fax: (301) 314 9067
Medium: 4GBDAT
Subject: AGN

THE IONIZATION FRACTION OF OBSCURING MATERIAL IN ACTIVE GALACTIC NUCLEI


ABSTRACT

We propose to obtain an ASCA spectrum of the water vapor megamaser and Seyfert 2 galaxy NGC 3735. The primary desired parameter is the equivalent hydrogen column to the nucleus. This column will be combined with our VLBA observations of the radio spectrum of the compact (sub-pc) nucleus. Low radio frequency turnovers in the spectra of water vapor megamaser galaxies are believed to result from free-free absorption in their edge-on disks. Combination of their photoelectric and free-free absorbing columns will allow the average ionization fraction of the disk to be derived and compared with theory. We shall also check the expectation that water megamaser Seyfert 2s have higher columns than other Seyfert 2s.

CO-INVESTIGATORS
CO-I NAME INSTITUTE COUNTRY
KIMBERLY WEAVERJOHNS HOPKINS UNIVUSA
JAMES BRAATZNRAOUSA
CHRISTIAN HENKELMPIFR, BONNGERMANY
LINCOLN GREENHILLCENTER FOR ASTROPHYSUSA
JAMES HERRNSTEINNRAOUSA

TARGETS

TARGET NAMEPRIRADECTIMETCOFFGISSIS CNTOBS
1)NGC 3735
C
173.9988 70.5350
60 ks
N
Y
P
0.04200
1