Rossi X-ray Timing Explorer
Artist impression of RXTE telescope
|Major contractors||MIT · GSFC|
|Launch date||30 December 1995 at 13:48:00 UTC|
|Launched from||Cape Canaveral SLC-17A|
|Launch vehicle||Delta II 7920|
|Mass||3,200 kilograms (7,100 lb)|
|Type of orbit||circular orbit|
|Orbit height||600 km|
|Orbit period||92.5999984741211 minutes|
|All Sky Monitor (ASM)||Energy range: 2-12 keV|
|Proportional Counter Array (PCA)||Energy range: 2-60 keV|
|High-Energy X-ray Timing Experiment (HEXTE)||Energy range: 15-250 keV|
|Website||RXTE home page|
|Apoapsis||4,090 kilometres (2,540 mi)|
|Periapsis||4,090 kilometres (2,540 mi)|
The Rossi X-ray Timing Explorer (RXTE) is a satellite that observed the time structure of astronomical X-ray sources, named after Bruno Rossi. The RXTE has three instruments—the Proportional Counter Array, the High-Energy X-ray Timing Experiment (HEXTE), and the All Sky Monitor. The RXTE observed X-rays from black holes, neutron stars, X-ray pulsars and X-ray bursts. It was funded as part of the Explorer program, and is sometimes also called Explorer 69.
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 dwarfs and from other stars' coronae. In April 2008, RXTE data was used to infer the size of the smallest known black hole.
RXTE ceased science operations on 3 January 2012.
NASA scientists said that the decommissioned RXTE would re-enter the Earth's atmosphere "between 2014 and 2023".
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 were:
- Energy range: 2-12 keV
- Time resolution: 80% of the sky every 90 minutes
- Spatial resolution: 3' × 15'
- Number of shadow cameras: 3, each with 6 × 90 degrees FOV
- Collecting area: 90 cm2
- Detector: Xenon proportional counter, position-sensitive
- Sensitivity: 30 mCrab
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 investigator was Dr. Jean H. Swank.
The instrumental properties were:
- Energy range: 2-60 keV
- Energy resolution: < 18% at 6 keV
- Time resolution: 1 µs
- 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 could "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 was provided by using a 241Am radioactive source mounted in each detector's field of view. The HEXTE's basic properties were:
- Energy range: 15-250 keV
- Energy resolution: 15% at 60 keV
- Time sampling: 8 microseconds
- Field of view: 1 degree FWHM
- Detectors: 2 clusters of 4 NaI/CsI scintillation counters
- Collecting area: 2 × 800 cm2
- Sensitivity: 1 Crab = 360 count/s per HEXTE cluster
- Background: 50 count/s per HEXTE cluster
- The RXTE All Sky Monitor Data Products
- "RXTE Mission". Heasarc.gsfc.nasa.gov. 2002-02-22. Retrieved 2012-02-03.
- "Dying Star Reveals More Evidence for New Kind of Black Hole". ScienceBlog.com. Retrieved 2012-02-03.
- "Galactic Glow Gleaned".
- "NASA Scientists Identify Smallest Known Black Hole". 2008-04-01.
- "The RXTE Mission is Approaching the End of Science Operations". 2012-01-04.
- "NASA's ageing black hole-stalking probe switched off". 2012-01-11.
- "All-Sky Monitor (ASM)". Heasarc.gsfc.nasa.gov. 2002-02-04. Retrieved 2012-02-03.
- "Proportional Counter Array (PCA)". Heasarc.gsfc.nasa.gov. 2006-08-08. Retrieved 2012-02-03.
- "High Energy X-ray Timing Experiment (HEXTE)". Heasarc.gsfc.nasa.gov. 1999-09-14. Retrieved 2012-02-03.
|Wikimedia Commons has media related to RXTE.|
- MIT's Rossi X-Ray Timing Explorer Project
- NASA Mission Site
- Video documentary
- Variations in the X-ray Sky by RXTE (1997)