SUMMARY OF PROPOSAL 72111
UNIVERSITY OF COLORADO
CAMPUS BOX 440
BOULDER
COLORADO USA 80303
Tel: +1-303-492-4610 Fax: +1-303-492-5235
Medium: CD ROM
Subject: AGN
ASCA OBSERVATIONS OF NGC4258: TESTING THE STRONG ADAF PRINCIPLE
ABSTRACT
We propose a 200ks ASCA observation of the low-luminosity AGN NGC4258 which we plan to make simultaneous with RXTE observations. This object has become the test-bed of the so-called `Strong ADAF Principle' which states that an accretion disk will always be an Advection Dominated Accretion Flow (ADAF) if the mass accretion rate is below a critical value. Our joint ASCA/RXTE data will allow us to search for a broad iron line in the X-ray spectrum of NGC4258. The detection of any such line will point to the presence of a cold, radiatively efficient accretion disk rather than a hot advective flow and provide a firm counter-example to the Strong ADAF Principle. This is of fundamental importance to our understanding of accretion disk physics.
CO-INVESTIGATORS
| CO-I NAME | INSTITUTE | COUNTRY |
|---|
| MICHAEL NOWAK | JILA, BOULDER | USA |
| JOERN WILMS | IAA, TUEBINGEN | GERMANY |
| PHILIP MALONEY | CASA, BOULDER | USA |
| MITCHELL BEGELMAN | JILA, BOULDER | USA |
TARGETS
| TARGET NAME | PRI | RA | DEC | TIME | TC | OFF | GIS | SIS CNT | OBS |
|---|
| 1)NGC4258 | B | 184.7417 | 47.3039 | 200 ks | N | N | P | 0.10000 | 1 |