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RXTE News Archive: 2008 RXTE


PCA: Filter Out Breakdown Events

December 16, 2008

The PCA team has a new method to help users remove high-voltage breakdown events which can contaminate PCA data. See the new RXTE recipe, Dealing with PCA Breakdown Events.

Two Black Holes Teach Astronomers a Lesson

October 15, 2008

Observations of two different systems -- both containing stellar-mass black holes -- are showing astronomers how much they have yet to learn. Coordinated observations of these systems using the European Southern Observatory's Very Large Telescope and NASA's Rossi X-ray Timing Explorer reveal surprising dips in optical brightness moments before high-energy flares erupt.

The systems are Swift J1753.5-0127 -- discovered by NASA's Swift satellite -- and GX 339-4. In them, a black hole and a normal star orbit a few million miles apart. That's less than 10 percent of the distance between Mercury and our sun. [Read More]

RXTE Cycle 13 Announced

September 19, 2008

NASA has approved extending RXTE operations beyond the nominal end of Cycle 12 (December 2008) through September 2009. For more information, see the RXTE Cycle 13 Information Page.

RXTE SOF Realtime Data Area Has Moved

August 14, 2008

The RXTE SOF's Realtime and Pseudo-production data retrieval site has moved. If you are looking for the SOF's Realtime or Pseudo-production data areas, the new, permanent sites are:

Please remove old bookmarks for these areas and replace them with the new sites! Thanks for your patience with this transition. The new site is expected to be faster and more robust.

New RXTE Mission-Long Data Products

May 12, 2008

The RXTE Guest Observer Facility (GOF) has begun generating Mission-Long Data Products based on the standard data products (StdProds) from the PCA and HEXTE, for over 200 sources that have been observed many times with RXTE during its mission. These products combine all "good" RXTE observations for a given source, over the lifetime of the RXTE mission.

The mission-long data products are intended to give a researcher an idea of how much, and what quality of, data are available in the RXTE public archive for their sources of interest. They are not meant to replace the careful reduction and analysis by individual scientists, but rather to lead them towards data that will be suitable to their needs. Users should bear in mind that only a single point is included for an observation. And thus the impressive variability seen by many RXTE targets on short timescales is entirely overlooked in the mission-long data products.

For more information, see our Mission-Long Data Products Guide.

RXTE Discovers Stellar Ticking Time Bomb Explodes on Cue

April 30, 2008

A team of researchers led by Diego Altamirano has discovered how to predictx-ray bursts from the low mass x-ray binary system 4U 1636-53. For more information,see:

NASA PressRelease
Astrophysical Journal paperv673: L35-L38, January 2008
"Different manifestations of accretion onto compact objects",D. Altamirano PhD thesis, April 2008

RXTE Finds Smallest Known Black Hole

April 1, 2008

Two NASA scientists announce that a binary system discovered by RXTE containsthe smallest known black hole - a 3.8 solar mass featherweight. The researcherspresented their results at the American Astronomical Society High-Energy AstrophysicsDivision meeting in Los Angeles, California.

For more information, see:

NASAPress release

Powerful Explosions Suggest Neutron Star Missing Link

February 21, 2008

Researchers using RXTE and Chandra report the first ever observations of magnetar-like bursts from a normal young pulsar: "We are watching one type of neutron star literally change into another right before our very eyes. This is a long-sought missing link between different types of pulsars," says lead author Fotis Gavriil of NASAs Goddard Space Flight Center in Greenbelt, Md., and the University of Maryland, Baltimore. The results appear inthe February 21 issue of Science Express.

For more information, see:

NASA Press Release
Science Express article (February 21, 2008)

PCA SAA History File Production Resumes

February 1, 2008

Production of the PCA SAA History file, used for PCA background generation, has resumed. Users can retrieve the file from the usual area: ftp://legacy.gsfc.nasa.gov/xte/calib_data/pca_bkgd/pca_saa_history.gz This notice officially rescinds the earlier news item about the PCA SAA History file (released Jan. 22, 2008).

Temporary Interruption of PCA SAA History File Production

January 22, 2008

Production of the PCA SAA History file, used for PCA background generation, has been temporarily interrupted. The latest file available contains PCA SAA History data up through January 20, 2008. To analyze PCA data beyond that date, please use the predictive SAA history file, located in the same part of the XTE FTP area:


A similar notice will be posted when PCA SAA History file production resumes.

ASM Source Intensity Errors for Sources in Crowded Fields (infrequent but significant)

January 2008


A significant problem with a small number of ASM source intensities in the light curve of a Galactic X-ray source has recently come to attention. Please see the "Important Caveat" section of the MIT ASM light curves page.

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