Number 24, March 2003
Contents: 1) FUSE Cycle 4 results 2) Fourth Annual FUSE Science and Data Workshop, May 12-13, 2003 3) Scientific Results of the FUSE Mission, Victoria, B.C., August 2-6, 2004. 4) Detector 2 High Voltage Anomaly, December 8, 2002 - February 3, 2003. 5) CalFUSE v2.2.3 released 1) FUSE Cycle 4 results NASA announced the results of the Cycle 4 Guest Investigator proposal review at the end of January 2003. The observing programs selected for Cycle 4 are posted on the FUSE GI web page (fusegi.pha.jhu.edu). The Cycle 4 targets listed on the same site correspond to the proposed target lists of accepted programs, corrected for duplications between Cycle 4 programs and target restrictions as a result of the peer review. A total 179 proposals were submitted for Cycle 4 in two categories, Standard (164 proposals, 16.4 Msec) and Survey/Supplementary (13 proposals, 3.6 Msec). NASA accepted 99 Standard proposals (6579 ksec, including 310 ksec for TOO programs) and 13 proposals in the Survey/Supplementary category (2453 ksec). Even the number of submitted and accepted Survey proposals are the same, not all Survey proposals were accepted. Several proposals submitted in the Standard category were accepted as Survey programs. 2) Fourth Annual FUSE Science and Data Workshop, May 12-13, 2003 We would like to invite all new and seasoned FUSE users to the fourth Annual Science and Data Workshop, planned for May 12-13 in Baltimore. We are planning about half a day of operations and programmatical updates followed by presentations on science and data analysis. We invite those interested in giving a presentation to contact us at firstname.lastname@example.org with a suggested subject. We're expecting to have both oral and poster presentations with the oral presentations nominally planned as 30 min. talks. This year the workshop will run two days to be followed by a meeting of the FUSE Observer's Advisory Committee (FOAC) on Wednesday, May 14. So this will also be a good opportunity to come and meet your FOAC representatives! 3) Scientific Results of the FUSE Mission, Victoria, B.C., August 2-6, 2004. Please mark your calendars for a week-long symposium on the scientific results to date from the FUSE mission, scheduled for 2004, August 2-6, in Victoria, BC, Canada. This conference will cover a wide range of astronomical research. There will be invited reviews, contributed talks, and poster papers. Further details will be forthcoming during the spring and will be noted in future newsletters as well as on the FUSE web site. 4) Detector 2A High Voltage Anomaly Every six to twelve months, we raise the voltage on the FUSE detectors to compensate for the effects of detector gain sag. We did this most recently on 8 Dec. 2002. Shortly afterward, detector segment 2A began to experience high-voltage current transients, which resulted in a shut down of the detector 2 high voltage. Repeated attempts to return the voltage to its nominal level were unsuccessful. On 16 Dec. 2002, we decided to leave the voltage on segment 2A at a lower-than-nominal value while we investigated the problem. We were finally able to return segment 2A to its pre-December voltage on 3 Feb. 2003. Calibration data indicate that LiF 2A LWRS spectra obtained during this low-voltage period suffer significant walk effects, with typical shifts of 20 to 30 pixels in the raw data. The other LiF apertures (HIRS and MDRS) and the SiC channel of segment 2A are much less affected. The CalFUSE pipeline corrects time-tag data for walk, but the correction for histogram data is less satisfactory. Observers are urged to examine carefully LiF 2A LWRS spectra obtained in histogram mode during this low-voltage period. The low pulse heights seen in LiF 2A LWRS spectra have a second effect on FUSE data: detector background events, which generally have lower pulse heights than actual photon events, may fall below our low-pulse-height threshold. As a result, the detector background is reduced, and our background-subtraction modules -- which scale models to the background measured on regions of the detector with a more normal pulse-height distribution -- may over-estimate its intensity. This anomaly affects LiF 2A LWRS spectra obtained in both time-tag and histogram mode. The instrumental sensitivity shows no significant change during this low-voltage period. For more information, please see the CalFUSE White Paper "Time-Dependent FUSE Calibration Effects" at 5) CalFUSE v2.2.3 released FUSE data are now being processed at JHU with CalFUSE v2.2.3, a mild upgrade from CalFUSE v2.2.2. We have corrected a few bugs and made the pipeline more robust when dealing with really weird data. We've also updated the VOLT_CAL files to reflect detector-voltage changes over the past three months. If you would like to upgrade to CalFUSE v2.2.3, see the CalFUSE web page at
The Observer's Electronic Newsletter is published by the FUSE project and is aimed at the FUSE user community.
Editor: B-G Andersson, FUSE Guest Investigator Officer.
The FUSE Project is managed by Johns Hopkins University's Center for Astrophysical Sciences in Baltimore, MD, for NASA's Goddard Space Flight Center. The FUSE Principal Investigator is Dr. Warren Moos, the FUSE Project Manager at JHU is Mr. J.B. Joyce, and the NASA Project Scientist for FUSE is Dr. George Sonneborn.
Further information about the FUSE Guest Investigator Program can be obtained from: Dr. George Sonneborn; email@example.com
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