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RXTE News Archive: 2007 RXTE


Bizarre Planet-Mass Object Found Orbiting Neutron Star

September 12, 2007

Researchers using RXTE and Swift announce the discovery of a planet-massed object orbiting a newly discovered millisecond pulsar. The object, estimated at several Jupiter masses, is probably the inner core of a companion star that lost its outer layers to the pulsar. For more information, see:

Brief period of incomplete Archive-mode data from HEXTE Cluster A

May 21, 2007

Data taken in Archive-mode on HEXTE Cluster A between April 24 at 23:27 and May 4 at 20:00 UT may be incomplete. Cluster A archive data experienced a period of elevated data drop-outs during that time, with observations losing anywhere from 20%-100% of their cluster A archive data. Event mode data taken in Cluster A was largely unaffected (data losses of a few percent above normal for most observations), and cluster B was completely unaffected: both archive-mode and event data from cluster B are fine during this period. A reboot of Cluster A restored archive-mode data to normal. All spacecraft systems are currently healthy, and no errors or damage have been found. The cause of this anomaly remains under investigation.

Recommended Cycle 12 Targets Released!

May 2, 2007

The review of RXTE Cycle 12 proposals took place in April 2007. An international panel of scientists convened to discuss the 153 unique proposals that were submitted for consideration this year. The proposals and targets that were recommended to NASA Headquarters by the review panel are now available online. NOTE: Cycle 12 proposal numbers are distinguished by their leading two digits: 93NNN.

PIs should receive email notification of the results of their proposal, along with comments from the review panel, within the next several weeks. Note that Cycle 12 solicited proposals for satellite time only, so there will be no "Stage 2" review for grants. Successful proposers are welcome to submit proposals for funding to NASA's Astrophysics Data Analysis Program (solicitation NNH07ZDA001N-ADP), covered by Appendix D2 of the ROSES 07 solicitation. The due date is June 22, 2007. Notices of Intent were due Apr 27, 2007, but are not required.

Congratulations to all successful Cycle 12 PIs!

RXTE Archive Downtime: 18:00 Jul 13 - 12:00 Jul 14, EDT

July 11, 2007

The RXTE Archive, PGPData area, anonymous-FTP area, and all RXTE Web pages will be unavailable from 18:00 Jul 13 - 12:00 Jul 14, EDT (Friday evening through Saturday morning, Eastern US time), due to maintenance on the local power system. Please be patient if the system is not fully responsive immediately after the downtime - it may take a little while to restore all functions. Also, the XTEHELP and XTEPLAN e-mail addresses will be effected by this outage - no mail will be delivered to these addresses during the downtime. We apologize for any inconvenience this may cause.

RXTE Cycle 12 Proposal Deadline is Past! Review Preparations Underway!

March 23, 2007

The RXTE Cycle 12 proposal deadline was January 26, 2007. We received 153 proposals for RXTE observations with a total time request of 102 Ms. We are delighted that the community shows continued interest in utilizing the unique capabilities of RXTE, with an impressive broad science program proposed, including coordinated programs with GLAST, Swift, Suzaku, and many other ground-based and space-based observatories. The Cycle 12 proposal review will take place in mid-April, and the accepted targets list will be posted shortly after the conclusion of the review. Cycle 12 observations will begin in June 2007.

RXTE Cycle 12 Update & Deadline Reminder

January 26, 2007

The deadline to submit proposals for Cycle 12 is fast approaching: 4:30pm ET on January 26, 2007. Cycle 12 has many changes from previous RXTE Cycles - please see our newly reorganized Cycle 12 Web page for further details.

Special Note for PIs of Cycle 11 monitoring campaigns:

PIs who have Cycle 11 monitoring campaigns and wish to continue them in Cycle 12 should submit a Cycle 12 proposal to continue monitoring - the XTE project will then extend the Cycle 11 observations until the Cycle 12 Peer Review. (Extension time will be provided by the XTE project, not deducted from Cycle 12 proposed time.) Proposals accepted at the Peer Review will then be extended until the start of Cycle 12.

TNO Occultations May Be Instrumental Deadtime

January 16, 2007

MIT researchers report that the millisecond dips in Sco X-1 found by Chang et al. (2006) and interpreted as occultations by trans-Neptunian objects (TNOs) may in fact be the result of high-energy charged particle events in the RXTE PCA detectors. The results were originally announced in ATEL #949, and are now available in:

PCU 1 Loses Top Propane Layer

January 12, 2007

On Dec. 25 at 12:56:08 UT, PCU 1 (in the 0-4 numbering scheme) developed a pinhole leak in its propane layer, consistent with a micrometeorite hit. This is similar to the loss PCU 0 suffered in May 2000 and in keeping with estimated micrometor hit rates. The impact on performance of the entire PCA is expected to be minimal; PCU 1 is only used about 15% of the time and not at all for weak sources. It's performance should be similar to that of PCU 0 now, suitable for use on galactic sources and timing observations. The PCA team cautions that a new response matrix and possibly new background model will be necessary for PCU 1; work is beginning on those issues, and expected to take several months.

PCU 1 was turned off when the decreasing propane pressure was detected, and turned back on at 20:29 UT on Dec. 28. RXTE Standard Products lightcurves and spectra from Dec. 28 on will not include data from PCU 1. (Just as Standard Products made after the May 2000 PCU 0 propane loss do not include PCU 0 data.) If you have further questions about how this loss might effect past or planned observations, please write to the XTE team using our Feedback form.

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