Hubble Space Telescope

Hubble Space Telescope ACS filenames

ACS filenames

Note: The NICMOS files names are all starting with the letter 'N'

Note: The 9th character of an association of simple observation is always '0' at CADC

Note: Please consult the full documentation Here

CADC file names File Suffix Description Units Type Access Example
nxxxxxxxx_raw.fits _RAW.FITS This FITS file contains the raw image data received from the spacecraft. One file per exposure is created (a MULTIACCUM exposure is considered a single exposure irrespective of the number of samples specified). RAW n4rk020b0_raw
nxxxxxxxx_spt.fits _SPT.FITS This FITS file contains supporting information about the observation, the spacecraft telemetry and engineering data from the instrument that was recorded at the time of the observation, including detector temperature measurements. RAW n4rk020b0_spt
nxxxxxxxx_asn.fits _ASN.FITS This file is a FITS binary table that contains the list of datasets making up an association. RAW n4rk020b0_asn
nxxxxxxxx_cal.fits _CAL.FITS This FITS file contains the calibrated science data for an individual dataset, and is produced by the pipeline calibration task calnica. The input to calnica are the _raw images. For a MULTIACCUM exposure, this file contains a single science image formed by combining the data from all samples. CAL n4rk020b0_cal
nxxxxxxxx_ima.fits _IMA.FITS This FITS file is also produced by the pipeline task calnica and contains the calibrated science data for all samples of a MULTIACCUM dataset before the process of combining the individual readouts into a single image has occurred. This file is only produced for MULTIACCUM observations. CAL n4rk020b0_ima
nxxxxxxxx_mos.fits _MOS.FITS These FITS files contain the composite target and, for chopped pattern sequences, background region images constructed by the pipeline task calnicb for an associated set of observations. The input to calnicb are the calibrated _cal images from calnica and the _asn association table. Target images are co-added and background-subtracted. The value of the last character of the rootname is 0 for targets, and 1 to 8 for background images. These files are only produced for an associated set of observations. CAL n4rk020b0_mos
nxxxxxxxx_asc.fits _ASC.FITS This table is produced by the pipeline calibration task calnicb, and is the same as the association table _asn, with the addition of new columns which report the offsets between different images of the mosaic or chop pattern as calculated by calnicb, and the background levels computed for each image. This file is only produced for an associated set of observations. CAL n4rk020b0_asc
nxxxxxxxx_trl.fits _TRL.FITS This FITS ASCII table contains a log of the pipeline calibration processing that was performed on individual datasets and mosaic products. CAL n4rk020b0_trl
nxxxxxxxx_pdq.fits _PDQ.FITS This FITS ASCII table provides quality information on the observation, mostly on pointing and guide star lock. Possible problems encountered, e.g., a loss of guide star lock or a guide star acquisition failure, are reported here. RAW n4rk020b0_pdq
nxxxxxxxx_epc.fits _EPC.FITS This FITS binary table is produced by the Engineering Data Processing System (EDPS) as an aid for use in calibration and temperature monitoring. Nine NICMOS Cooling System (NCS) mnemonics and five temperature sensors are bundled together into an STSDAS FITS table. RAW n4rk020b0_epc
nxxxxxxxx_prev.fits _prev.fits Preview in fits format PREVIEW n4rk020b0_prev.fits
nxxxxxxxx_prev.png _prev.png Preview in png format PREVIEW n4rk020b0_prev.png
NXXXXXXXX_jitter.png _JITTER.PNG Graphical representation of the jitter information OMS n4rk020b0_jitter.png

Note: The *_raw.fits, *_cal.fits, *_ima.fits, and *_mos.fits files are all defined as science data files, as they contain the images of interest for scientific analysis.

The data for an individual NICMOS science readout consist of five arrays, each stored as a separate image extension in the FITS file. The five data arrays represent:

  • The science (SCI) image from the detector.
  • An error (ERR) array containing an estimate of the statistical uncertainties (in units of 1) of the science data.
  • An array of bit-encoded data quality (DQ) flags representing known status or problem conditions of the science data.
  • An array containing the number of data samples (SAMP) that were used to compute each science image pixel value.
  • An array containing the effective integration time (TIME) for each science image pixel.