SUMMARY OF PROPOSAL 52045

DR. SAEQA DIL VRTILEK
SVRTILEK@CFA.HARVARD.EDU

SMITHSONIAN ASTROPHYSICAL OBSERVATORY
60 GARDEN STREET
CAMBRIDGE
MASSACHUSETTS USA 02138
Tel: (617)495-7094 Fax: (617)496-7577
Medium: 4GBDAT
Subject: X-RAY BINARIES

4U1700-37 WITH ASCA/STIS/XTE: WIND INSTABILITIES IN A SUPERGIANT BINARY


ABSTRACT

We propose to observe 4U1700-37 simultaneously with ASCA, HST, and XTE at 2 binary phase intervals (in and out of eclipse). The X-ray spectrum is soft with numerous lines during eclipse and hard and non-thermal outside eclipse; several UV P Cygni profiles show changes with orbital phase and possibly X-ray intensity. The X-ray flux is dominated by flaring activity (likely representing inhomogeneities in the wind) involving intensity increases by factors of 10-100 on timescales (1000s) not as yet resolved in the ultraviolet. We will examine the UV emission on timescales that fully resolve the X-ray variability. This will enable us to analyze the density structure and composition of the wind and test models for X-ray/UV line emission in wind-fed accretion systems.

CO-INVESTIGATORS
CO-I NAME INSTITUTE COUNTRY
BRAM BOROSONSAOUSA
MICHAEL CORCORANNASA/GSFCUSA
TIM KALLMANNASA/GSFCUSA
RICHARD MCCRAYJILAUSA

TARGETS

TARGET NAMEPRIRADECTIMETCOFFGISSIS CNTOBS
1)4U1700-37
1
255.9833-37.8439 30 ksY
Y
P
5.00000
1
2)4U1700-37
1
255.9833-37.8439 30 ksY
Y
P
0.50000
1

TARGET 1

TO BE COORDINATED WITH HST. ONE OF TWO PHASE INDEPENDENT OBSERVATIONS. SPANS A 0.7 DAY INTERVAL (ORBITAL PHASES 0.45-0.65) FOR A TOTAL OF 30KSEC.
COORDINATED OBSERVATION: START: Aug 18,1997 at 00STOP: Sep 27,1997 at 00
Epoch: 49262.0974 Period: 3.41172000 Min: 0.4500Max: 0.6500

TARGET 2

TO BE COORDINATED WITH HST. ONE OF TWO PHASE INDEPENDENT OBSERVATIONS. SPANS A 0.7 DAY INTERVAL (ORBITAL PHASES 0.95-1.15) FOR A TOTAL OF 30KSEC.
COORDINATED OBSERVATION: START: Aug 18,1997 at 00STOP: Sep 27,1997 at 00
Epoch: 49262.0974 Period: 3.41172000 Min: 0.9500Max: 1.1500