SUMMARY OF PROPOSAL 52125

DR. WILLIAM NIELSEN BRANDT
NIEL@CFA.HARVARD.EDU

SMITHSONIAN INSTITUTION ASTROPHYSICAL OBSERVATORY
60 GARDEN STREET
CAMBRIDGE
MA USA 02138
Tel: (617) 495-7442 Fax: (617) 495-7356
Medium: 2GBDAT
Subject: AGN

ASCA OBSERVATIONS OF BRIGHT, ULTRASOFT, NARROW-LINE SEYFERT 1 GALAXIES


ABSTRACT

Recent ROSAT observations of narrow-line Seyfert 1s (NLS1) have shown that they often have very steep soft X-ray spectra as well as rapid and sometimes amazing X-ray variability. Their peculiar behavior may arise via extremal values of some underlying physical parameter such as accretion rate. We have selected several bright and ultrasoft NLS1 for observation with ASCA. We will measure their hard X-ray spectra to see if they are different from those of more typical Seyfert 1s. Some NLS1 do appear to have unusual hard X-ray spectra, and it is very important to understand how widespread this phenomenon is since it directly probes new Seyfert physics. We will study rapid and large amplitude flux variability as well as spectral variability.

CO-INVESTIGATORS
CO-I NAME INSTITUTE COUNTRY
THOMAS BOLLERMPE GARCHINGGERMANY
MARTIN ELVISSAOUSA
CHIKO OTANIRIKENJAPAN

TARGETS

TARGET NAMEPRIRADECTIMETCOFFGISSIS CNTOBS
1)RX J 0148-27
1
27.0929-27.9739 40 ksN
Y
P
0.20000
1
2)MRK 1044
3
37.5229 -8.9980 40 ksN
Y
P
0.50000
1