SUMMARY OF PROPOSAL 62042
THE PENNSYLVANIA STATE UNIVERSITY
DAVEY LAB
UNIVERSITY PARK
PENNSYLVANIA USA 16802
Tel: (814) 865-0418 Fax: (814) 863-3399
Medium: 2GBDAT
Subject: X-RAY BINARIES
A COORDINATED ASCA/RXTE STUDY OF CIRCINUS X-1 DURING ZERO PHASE
ABSTRACT
We propose ASCA/RXTE observations of Cir X-1 during one of its zero phase transitions. An earlier, short ASCA observation showed strong and variable iron K spectral features, and we want to study these features for more time to test the direct flux plus scattered flux model that we have put forward. RXTE observations, despite their low spectral resolution, suggest that the earlier ASCA observation probably missed some interesting spectral behavior that would greatly benefit from a higher spectral resolution study. The iron K line appears to vary in equivalent width and the iron K edge threshold energy appears to increase up to 7.7 keV. The high spectral resolution of ASCA coupled with the broad band and large effective area of RXTE will allow the best spectral study of Cir X-1 yet.
CO-INVESTIGATORS
TARGETS
| TARGET NAME | PRI | RA | DEC | TIME | TC | OFF | GIS | SIS CNT | OBS |
|---|
| 1)CIRCINUS X-1 | 1 | 230.1708 | -57.1667 | 80 ks | Y | Y | P | 50.00000 | 1 |
TARGET 1
NOTE THAT CIRCINUS X-1 DOES NOT HAVE A SIMPLE LINEAR EPHEMERIS EQUATION. PLEASE USE THE EPHEMERIS IN GLASS (1994) AND CONTACT ME.
Epoch: 43076.8700 Period: 16.57680000 Min: 0.9500Max: 0.0500