Number 25, March 2003
Contents: 1) Second Announcement, Fourth Annual FUSE Science and Data Workshop 2) CalFUSE Problem with Error Bars in Time-Tag Mode, v2.1.6 1) Second Announcement, Fourth Annual FUSE Science and Data Workshop Second Announcement Call for Papers: Fourth Annual FUSE Science and Data Workshop May 12-13, 2003 Held at STScI, Baltimore MD In the last FUSE Electronic Newsletter we announced the upcoming two day FUSE Science and Data Workshop which will be held in Baltimore at STScI on May 12 and 13, 2003. Herewith we announce the deadline for receipt of abstracts for this meeting, which is Friday April 11, 2003. Both oral (25 minutes plus time for questions) and poster presentation formats are available. If desired, shorter oral presentations (10 minutes with time for questions) will also be supported. Hence, please submit title, first author, brief abstract (300 words or less), preference for oral or poster presentation, and in the former case a preferred length to firstname.lastname@example.org prior to the deadline. In response to the Newsletter announcement, we have already received some submissions. These do not have to be resubmitted unless you did not specify poster or oral presentation or if the materials submitted were otherwise incomplete. To allow us a better basis for planning, we'd also like to ask that you submit a non-binding registration if you plan to attend, whether giving a paper or not to email@example.com. We have set up a web page where we will post further information as it becomes available: Any questions should be addressed to the e-mail address above. We hope to see you in Baltimore in May! 2) CalFUSE Problem with Error Bars in Time-Tag Mode, v2.1.6 One of the changes included in CalFUSE v2.1.6, released about a year ago, was a modification of the way that error bars for individual pixels are calculated in the final, motion-corrected detector image are then propagated into the extracted spectra. It was recently pointed out that our new algorithm does not yield SQRT(N) error bars for bright sources (fluxes > 1E-12 erg/cm2/s/A). The trouble arises when we normalize the error for each detector pixel by 1/N^2. For most targets, the number of counts per detector pixel is zero or one, so this normalization has no effect. For bright targets, N can be as large as 3 or 4, so the error bars are greatly reduced. After considerable debate, we have decided to return to the 1/N normalization originally used by the CalFUSE pipeline. To see if your data are affected, compare the CNTSERR array with SQRT(COUNTS). For most targets, you will find that the two arrays are comparable. If not, a simple solution is to replace the flux-calibrated ERROR column with FLUX/SQRT(COUNTS). Because the COUNTS array is background subtracted, SQRT(COUNTS) is slightly less than SQRT(N). For bright targets, however, the difference will be negligible. A new version of the pipeline module in question, v1.23 of cf_ttag_geodopp.c, is available on the CalFUSE FTP site at ftp://fuse.pha.jhu.edu/fuseftp/calfuse/BUG_FIXES . A version of CalFUSE employing this new module, dubbed v2.3.0, will be installed behind the firewall later this month. For more information, please see the CalFUSE White Paper "Error Propagation in CalFUSE" 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; firstname.lastname@example.org
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