Title: Connections between Line Emission, Radio Jets and Spectral States in the Black Hole X-Ray
Transient 4U 1630-47
Proposal ID: 0120112
Subject category: Compact Object
Principal investigator: Tomsick
Institute: University of California, San Diego
Abstract
The X-ray flux observed from X-ray transients changes by several orders of
magnitude between quiescence and
outburst, providing an opportunity to learn
about black hole candidates (BHCs), accretion onto compact
objects and the
processes responsible for high energy emission. The high energy emission
provides a probe
of the regions of space close to the compact object,
allowing us to study strong gravity and jet formation
processes. 4U 1630-47
is the only BHC X-ray transient that has outbursts which recur on a
relatively
regular and short time scale. In addition to having a high level
of activity, the source produces strong
hard X-ray emission, and optically
thin, highly polarized synchrotron radio emission, indicating the
presence of
jets. We propose to observe 4U 1630-47 with INTEGRAL along with contemporaneous
radio
observations in order to: 1. measure the properties of high energy
emission lines (if they are present),
including the narrow electron-positron
annihilation line at 511~keV and the 300-500~keV lines of uncertain
origin
that have been observed in other systems; 2. determine the relationship between
the radio and high
energy emission; and 3. measure the energy spectra in the
hard and soft states to place constraints on
accretion geometries and emission
mechanisms. The high spectral resolution, good sensitivity and broadband
capabilities of INTEGRAL are critical for achieving the goals of this proposal.