Rossi X-ray Timing Explorer
Encyclopedia
The Rossi X-ray Timing Explorer (RXTE) is a satellite that observes the time structure of astronomical X-ray sources. The RXTE has three instruments—the Proportional Counter Array, the High-Energy X-ray Timing Experiment (HEXTE), and one instrument called the All Sky Monitor. The RXTE observes X-rays from black holes, neutron stars, X-ray pulsars and x-ray bursts.
RXTE was launched from Cape Canaveral
on 30 December 1995 on a Delta rocket, has an International Designator
of
1995-074A and a mass of 3200 kg.
Observations from the Rossi X-ray Timing Explorer have been used as evidence for the existence of the frame-dragging
effect predicted by the theory of general relativity
. RXTE results have, as of late 2007, been used in more than 1400 scientific papers.
In January 2006 it was announced that Rossi had been used to locate a candidate intermediate-mass black hole
named M82 X-1. In February 2006 data from RXTE was used to prove that the diffuse background X-ray glow in our galaxy comes from innumerable, previously undetected white dwarf
s and from other stars' corona
e. In April 2008 RXTE data was used to infer the size of the smallest known black hole.
It was built by the CSR at MIT. The principal investigator
was Dr. Alan M. Levine.
was Dr. Jean H. Swank.
The instrumental properties are:
The HEXTE was designed and built by the Center for Astrophysics & Space Sciences (CASS) at the University of California
, San Diego. The HEXTE principal investigator
was Dr. Richard E. Rothschild.
RXTE was launched from Cape Canaveral
Cape Canaveral
Cape Canaveral, from the Spanish Cabo Cañaveral, is a headland in Brevard County, Florida, United States, near the center of the state's Atlantic coast. Known as Cape Kennedy from 1963 to 1973, it lies east of Merritt Island, separated from it by the Banana River.It is part of a region known as the...
on 30 December 1995 on a Delta rocket, has an International Designator
International Designator
The International Designator, also known as COSPAR designation, and in the United States as NSSDC ID, is an international naming convention for satellites...
of
1995-074A and a mass of 3200 kg.
Observations from the Rossi X-ray Timing Explorer have been used as evidence for the existence of the frame-dragging
Frame-dragging
Einstein's general theory of relativity predicts that non-static, stationary mass-energy distributions affect spacetime in a peculiar way giving rise to a phenomenon usually known as frame-dragging...
effect predicted by the theory of general relativity
General relativity
General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...
. RXTE results have, as of late 2007, been used in more than 1400 scientific papers.
In January 2006 it was announced that Rossi had been used to locate a candidate intermediate-mass black hole
Intermediate-mass black hole
An Intermediate-mass black hole is a black hole whose mass is significantly more than stellar black holes yet far less than supermassive black holes...
named M82 X-1. In February 2006 data from RXTE was used to prove that the diffuse background X-ray glow in our galaxy comes from innumerable, previously undetected white dwarf
White dwarf
A white dwarf, also called a degenerate dwarf, is a small star composed mostly of electron-degenerate matter. They are very dense; a white dwarf's mass is comparable to that of the Sun and its volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored...
s and from other stars' corona
Corona
A corona is a type of plasma "atmosphere" of the Sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse, but also observable in a coronagraph...
e. In April 2008 RXTE data was used to infer the size of the smallest known black hole.
All-Sky Monitor (ASM)
The ASM consists of three wide-angle shadow cameras equipped with proportional counters with a total collecting area of 90 square cm. The instrumental properties are:- Energy range: 2 - 10 keV
- Time resolution: 80% of the sky every 90 minutes
- Spatial resolution: 3' x 15'
- Number of shadow cameras: 3, each with 6 x 90 degrees FOV
- Collecting area: 90 cm²
- Detector: Xenon proportional counter, position-sensitive
- Sensitivity: 30 mCrab
It was built by the CSR at MIT. The principal investigator
Principal investigator
A principal investigator is the lead scientist or engineer for a particular well-defined science project, such as a laboratory study or clinical trial....
was Dr. Alan M. Levine.
Proportional Counter Array (PCA)
The PCA is an array of five proportional counters with a total collecting area of 6500 square cm. The instrument was built by the EUD (formerly 'LHEA') at GSFC. The PCA principal investigatorPrincipal investigator
A principal investigator is the lead scientist or engineer for a particular well-defined science project, such as a laboratory study or clinical trial....
was Dr. Jean H. Swank.
The instrumental properties are:
- Energy range: 2 - 60 keV
- Energy resolution: < 18% at 6 keV
- Time resolution: 1 microsec
- Spatial resolution: collimator with 1 degree FWHM (Full Width at Half Maximum)
- Detectors: 5 proportional counters
- Collecting area: 6500 cm²
- Layers: 1 Propane veto; 3 Xenon, each split into two; 1 Xenon veto layer
- Sensitivity: 0.1 mCrab
- Background: 2 mCrab
The High Energy X-ray Timing Experiment (HEXTE)
The HEXTE consists of two clusters each containing four `phoswich scintillation detectors. Each cluster can "rock" (beamswitch) along mutually orthogonal directions to provide background measurements 1.5 or 3.0 degrees away from the source every 16 to 128 s. Automatic gain control is provided by using a 241Am radioactive source mounted in each detector's field of view. The HEXTE's basic properties are:- Energy range: 15 - 250 keV
- Energy resolution: 15% at 60 keV
- Time sampling: 8 microsecond
- Field of view: 1 degree FWHM
- Detectors: 2 clusters of 4 NaI/CsI scintillation counters
- Collecting area: 2 x 800 cm²
- Sensitivity: 1 Crab = 360 count/s per HEXTE cluster
- Background: 50 count/s per HEXTE cluster
The HEXTE was designed and built by the Center for Astrophysics & Space Sciences (CASS) at the University of California
University of California
The University of California is a public university system in the U.S. state of California. Under the California Master Plan for Higher Education, the University of California is a part of the state's three-tier public higher education system, which also includes the California State University...
, San Diego. The HEXTE principal investigator
Principal investigator
A principal investigator is the lead scientist or engineer for a particular well-defined science project, such as a laboratory study or clinical trial....
was Dr. Richard E. Rothschild.