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Data files

This chapter lists the file naming convention and give a brief description of the files that are included within an observation for the BAT, UVOT and XRT, as well as the files common to all instruments. The TDRSS messages and the different trend data type are also listed.

Filename convention

The Swift FITS science files are named according to the following convention:

where In addition, an index may be added to the filename to distinguish between files that would otherwise be identical named. This, for example, is used when splitting files that are too large in size, or when during calibration and verification the same TDRSS message type was sent multiple times.
While the XRT and UVOT follow always the above syntax, for the BAT there are exceptions, mainly for the data taken in survey mode.

Data content within an observation

This section lists the science data files included within the sequences that are archived. Currently within a sequence all Level 1 data files are available and some of the Level 2 files are present. The latter as well as Level 3 file can be derived using the Swift software starting from the Level 1 data. The file listing is given below, broken down by directory, together with the specific filenames.


Unless otherwise indicated all file are in FITS format.

In 2007 two additional files describing attitudes are added in the auxil directory. These are :

The first processed the sat attitude file to correct for attitude jumps, the second is derived using the UVOT data. They are not always present.


The files in this directory are all in HTML format.


The BAT data are divided into five subdirectories, each containing the following files:




NOTE: In some sequence there are a number of Level 1 superior of the Level 2. These excess of Level 1 lightcurves are to be considered not valid their content is already included in different files and they will be removed in subsequent data re-processing. .



NOTE: Pulsar mode is not always running. From July 2006 in fact it seems beeing turned off.



The UVOT instrument is equipped with several filters. Data files include in their names a two character string used as a mnemonic for the filter. These are :

Filter             Filter 
V          vv    |  White      wh
U          uu    |  VGRISM     gv
B          bb    |  UGRISM     gu
UVW1       w1    |  MAGNIFIER  mg
UVW2       w2    |  Blocked    bl
UVM2       m2    |

The UVOT data are divided into three subdirectories each containing the following files:


The filename of the UVOT event files changed in June 2006. The description below includes both naming. With the next data re-processing the new naming convention wil be apply to al data.

The uvot hardware window sizes are:

Size               YY value
0,0,128,128      |  w1
30,35,60,60      |  w2
41,46,38,38      |  w3
Unknown          |  wu


NOTE : The number of raw image file corresponds to the number of filters M used in Image mode only. If the same filter is used in Image and Event mode, the raw image file contains only the exposure taken in Image mode however the sky image contains both data taken in image and in event mode. The number N of sky and exposure files include data taken with filter in image or event mode (N > M).



Data from the XRT instrument are collected on-board via different read-out modes. Data files include in their names a two character string as the mnemonic for the modes. These are :
Image                   im
Piled-up Photodiode     pu
Low-rate Photodiode     lr
Windowed Timing         wt 
Photon Counting         pc 

The XRT data are divided into three subdirectories, each containing the following files:




TDRSS data

The TDRSS data consist of a number of files, corresponding to messages that are sent to the ground as soon as an on-board trigger occurs. Each instrument generates specific messages, the number of which depends on whether or not a position has been obtained. The filenaming convention for the TDRSS messages is the following


The TDRSS files and their names are :

Trend data

For each of the instruments, the trend and monitoring data files are organized by type. The main purpose of these data is to monitor various aspects of the instrument during the mission. These data are listed in the following tables by instrument, together with their filenames and the directory names where they are located. These data arrive on a daily basis in the archive. In most cases, a file contains data for an entire observation, therefore these files are updated on a daily basis until all the data for the observation has arrived.


Table 4.1: List of BAT trend data
Trend Type description Filename Directory
Americium detector plane histogram sw[obs_id]bamcbgXXXXoYYYY.dph bamdph
Americium gain sw[obs_id]bamcbgXXXXoYYYY.fits bamgain
Scaled map diagnostic sw[obs_id]bsmcb.fits bscalemap
for burst alert    
Detector Gain sw[obs_id]bcbgXXXX.fits bgain
Detector Offset sw[obs_id]bcboYYYY.fits boffset
Detector gain/Offset sw[obs_id]bcbgXXXXoYYYY.fits bgainoffs
Detector plane enable swt[MET time]bdecb.fits bdetflag
BAT commandables sw[obs_id]bcdtb.fits btbcommand
commanded table    
BAT on board catalog sw[obs_id]bcttb.fits bcatalog
On board veto sw[obs_id]bvttb.fits btbveto
On board long trigger sw[obs_id]blttb.fits btblongtr
On board short trigger sw[obs_id]bsttb.fits btbshorttr
On board rate trigger sw[obs_id]brttbrp.fits btbratetr
On board image trigger sw[obs_id]bittb.fits btbimgtr
Trigger flux sw[obs_id]bfxcb.fits btrigflx
Shell Log sw[obs_id]bshtb.fits bshelllg


Table 4.2: List of UVOT trend data
Trend Type description Filename Directory
Parameters for the compression sw[obs_id]ucm.fits ucompression
Centroid sw[obs_id]ucn.fits ucentroid
Engennering monitor sw[obs_id]umo.fits umon


Table 4.3: List of XRT trend data
Trend Type description Filename Directory
Diagnostic mode data: Raw frame sw[obs_id]xrf_rw.img xrawmode
Bias for the Photon Counting sw[obs_id]xbs_rw.img xbiasmode
Tam images sw[obs_id]xtm_rw.img xtam
Calibration sources sw[obs_id]xpc[ww]cb_uf.evt xcal
ww is the window size    


In addition to the instrumental trend data, there are four other types of files with general trend data. These are :

next up previous contents
Next: About this document ... Up: Swift Archive Guide Previous: Archive structure   Contents
Lorella Angelini 2007-04-03