Input Files

XRONOS currently supports two different types of input files:

• RATE BUFFERS (extension .rbf): these are binary files (with 128 words/rec) created by the EXOSAT interactive analysis and database software. They contain a 4 record header whose content is (in part) displayed when running most XRONOS applications. In short there are 5 types of rate buffers:

  (0) Type 0 rate buffers contain binned data (16 bins/rec); for each bin the center time (1 ms accuracy), dead time, count rate and error on count rate are stored. The barycentric time correction can either be applied to the bin center times, or stored in records 3-4 and applied by XRONOS at run time.

  (1) Type 1 rate buffers contain binned data (256 bins/rec); only the number of counts in the bin is stored. The barycentric time correction can be stored in records 3-4 and applied by XRONOS at run time.

  (2) Type 2 rate buffers contain binned data (64 bins/rec); for each bin the count rate and error on count rate are stored. The barycentric time correction can be stored in records 3-4 and applied by XRONOS at run time.

  (3) Type 3 rate buffers are not implemented yet.

  (4) Type 4 rate buffers contain photon arrival times (16 photons/rec). The layout of the data records is the same as in type 0 rate buffers.

  (5) PAT Rate buffers (Photon Arrival Time) have a different layout in that they can contain the photon arrival times of more than one source in the field of view of an imaging detector. Each PAT- subfile contains the data from one source. The number of events in each data record is 64.

  Note that for cases (4) and (5) an exposure file is required to reconstruct exactly the exposure during the observation (e.g. telemetry dropouts, data gaps, etc.). It is assumed that: (a) the exposure file is a type 0 rate buffer covering the same interval of the arrival time file; (b) its filename coincides with the rate buffer filename except that the first letter of the filename is replaced by a B. A warning is issued if such file is not found. In this case XRONOS assumes a 100 per cent exposure in each newbin.

• QDP FILES (extension .qXXX, where XXX can be any 3 characters) these are ASCII files written according to the QDP/PLT specifications. They consist of a header and a number of ``vectors", each written as a column. Xronos QDP files (see chapter 11 output_files) are an example of these files. To use QDP files as input to XRONOS applications it is essential that these have a two line header at least.

• Rate Buffers
• QDP Input Files
• Input File Options