HEXTE Modes
A HEXTE mode is the broad scheme for packaging the data, while the configuration is the specific implementation of the mode. When you work with HEXTE data, the configuration is more conspicuous than the mode itself - in XDF, for example, you'll specify "E_8us_256_DX0F" data to reduce rather than "Event List Mode" data. In fact, as a general rule, data in different configurations - even of the same mode - should not be reduced together. And of course, contemporaneous data in different configurations must never be combined since they're the same events!
Note that although there are five HEXTE data modes, there are only two basic formats used for the FITS data files, namely, Science Array (for Archive, Histogram Bin and Multiscalar Bin modes) and Science Event (for
Event List mode). Nearly all targets can be observed using Event List mode.
Here, we've summarized the modes and provided links to detailed descriptions of their configurations listed below. These descriptions focus on the data reduction aspects of the configurations, and, where file formats and keywords are discussed, complement the more general information in the Data Files chapter.
Given that your data set will include, per cluster, at most two configurations from the much larger number of possibilities, the descriptions are written to be complete and self-contained: you only need to read about your particular configurations:
- Archive Mode
is roughly equivalent to PCA Standard-1 and Standard-2. Always run, it is meant to provide a uniform and continuous archive of data collected over the lifetime of the mission. Under XDF, it appears as:
CL0ArchData Archive
CL1ArchData Archive
and always provides 64-channel spectra per detector, as well as 1.0-second lightcurves in four energy bands.
- Event List Mode
provides time-tagged information about every event that survives background rejection and passes through the various discriminator windows. A typical Event List configuration is E_8us_256_DX1F.
- Histogram Bin Mode
provides PHA histograms, separated by Detector (or not, as the case may be) every 1-16 seconds. A typical Histogram Bin configuration is B_16s_256_0_255_DF.
- Multiscalar Bin Mode
provides time histograms, with a resolution of 0.5 ms to 1 s, separated by Detector or not, in 2, 4, 6 or 8 PHA bands. A typical Histogram Bin configuration is B_1ms_1T_15_250_Q
- Burst List Mode
is a triggered version of Event List Mode providing event-by-event information for a short time period, thereby staying within average telemetry limitations. The configuration CE_8us_256_DX0F is an example.
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