RXTE ASM 2010 UpdateRXTE Guest Observer Facility - RXTE Frequently Asked Questions
The RXTE ASM color and lightcurve data have been updated, as of September 14, 2010.
The primary change in the revised data set is the stripping away of more than 12,300 time-isolated spikes caused by a solar glare problem.
Recent user inquiries about these spikes led to data study and additional filtering criteria that have now been applied for these FITS files and for all future data selections. The new filter (5 sigma detection in A-channel && fitted A count rate > sum-band count rate) supplements the other filters that we use, and it flags a spectral shape never seen in real X-ray sources.
The 12,300 bad events represent a very small portion of the total archive of 39.4 M measurements, but they are false and can cause problems for users.
These steps do not entirely eliminate spikes in "dead" (off) sources since there are systematic problems that are not affected by the new (plus old) filter(s), e.g., flux sharing from bright sources, and some soft spikes that are not strong enough to definitively separate them from the extreme range of real X-ray sources. However, more than half of the isolated spikes in our sample of 45 "dead" sources have just been eliminated, with no impact on persistent bright sources, and so this change has some value.
In addition, the new FITS masters provide mission-long light curves for the newest (2010) requested additions to the ASM monitoring catalog, which is now up to 581 sources.
If you have a question about RXTE, please send email to one of our help desks.