Title: Early Rises of X-ray Novae
Proposal ID: 0120274
Subject category: Compact Object
Principal investigator: Swank
Institute: NASA/GSFC
Abstract
We propose Target of Opportunity observations by INTEGRAL of the rising and peak phases of galactic
transients, triggered by RXTE. The scientific objective is to perform broad band observations during the
poorly understood early phase of black hole outbursts. For black holes, the beginning of the transient may
be the best oportunity to see the emission from a high temperature spherical infall, perhaps from between
the innermost stable orbit and the event horizon. Transients likely to be observed include X-ray novae and
sources of jet outflows. Observation with SPI and IBIS during the first few days of transients will
determine the nature of the accretion flow and high energy emission during the crucial beginning phase of
mass flow into the black hole. These measurements will extend to higher energies and have greater
sensitivity and higher duty cycle than has been possible before with RXTE, CGRO or GRANAT. We will use
JEM-X and IBIS to search for QPOs that often appear early in the outburst. Detection by INTEGRAL will help
to identify and observe the sources at other wavelengths. We will trigger based on RXTE ASM and PCA
monitoring, and anticipate 1-2 triggers in AO1. The proposed program will complement and not conflict with
INTEGRAL Core Program observations, which will typically occur at later times in the outburst. Our team
includes the RXTE Project Scientist and transient experts from RXTE and CGRO groups.