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Last modified: 28 October 2009


Data Products Guide

The Data Products Guide describes the contents and purpose of each Chandra data product. Detailed information is available for each of the following filetypes:

These pages may also be accessed from the tables of data products.

This document is a work in progress. For the most up-to-date description of the common Chandra data products, refer to the Introduction to the Data Products thread.

Primary Products

In March 2002, the data products were rearranged such that all products necessary for most analyses are in the primary directory.

Instrum Level Data product File Type Pipeline Filename template
ACIS L2 Events EVENTS ACIS2 acis*_evt2.fits
ACIS L2 TG Events EVENTS TG2 acis*_evt2.fits
ACIS L2 HIRESIMG IMAGE ACIS2 acis*_cntr_img2.fits
ACIS L2 LORESIMG IMAGE ACIS2 acis*_full_img2.fits
ACIS L2 Spectrum SPECTRUM TG2 acis*_pha2.fits
ACIS L2 Source list SRCLIST ACIS2 acis*_src2.fits
ACIS L1 Bad Pix BADPIX ACIS1 acis*_bpix1.fits
HRC L2 Events EVENTS HRC2 hrc*_evt2.fits
HRC L2 TG Events EVENTS TG2 hrc*_evt2.fits
HRC L2 HIRESIMG IMAGE HRC2 hrc*_cntr_img2.fits
HRC L2 LORESIMG IMAGE HRC2 hrc*_full_img2.fits
HRC L2 Spectrum SPECTRUM TG2 hrc*_pha2.fits
HRC L2 Source list SRCLIST HRC2 hrc*_src2.fits
HRC L1 Bad Pix BADPIX HRC1 hrc*_bpix1.fits
HRC L1 Livetime DTF HRC1 hrc*_dtf1.fits
PCAD L1 Aspect solution ASOL ASP1 pcad*_asol1.fits
Orbit L1 Orbit ephemeris ORBITEPHEM EPHEM1 orbit*_eph1.fits

Secondary Products

If you are interested in reprocessing your data, you will also need the level 1 files, which are in the secondary directory.

Instrum Level Data product HDU name Pipeline Filename Template
ACIS L1 Events EVENTS ACIS1 acis*_evt1.fits
ACIS L1 GTI GTI/MTL ACIS1 acis*_flt1.fits
ACIS L1 Mission Timline GTI/MTL ACIS1 acis*_mtl1.fits
ACIS L1 Bias BIAS ACIS1 acis*_bias0.fits
ACIS L1 Exp. Stats EXPSTATS ACIS1 acis*_stat1.fits
ACIS L1 Mask MASK ACIS1 acis*_msk1.fits
ACIS L1 Alignm. offsets ALIGN ACIS1 acis*_soff1.fits
ACIS L1 Aspect offsets ASPOFF ACIS1 acis*_aoff1.fits
HRC L1 Events EVENTS HRC1 hrc*_evt1.fits
HRC L1 GTI GTI/MTL HRC1 hrc*_std_flt1.fits
HRC L1 Mission Timline GTI/MTL HRC1 hrc*_mtl1.fits
HRC L1 Livetime stats DTFSTATS HRC1 hrc*_std_dtfstat1.fits
HRC L1 Alignm. offsets ALIGN HRC1 hrc*_soff1.fits
HRC L1 Aspect offsets ASPOFF HRC1 hrc*_aoff1.fits
PCAD L1 Aspect quality ASPQUAL ASP1 pcad*_aqual1.fits
PCAD L1 OBC aspect sol. ASOL ASP1 pcad*_osol1.fits
Solar L1 Solar ephemeris SOLAREPHEM EPHEM1 solar*_eph1.fits
Lunar L1 Lunar ephemeris LUNAREPHEM EPHEM1 lunar*_eph1.fits
Angles L1 Viewing angles ANGLES EPHEM1 angles*_eph1.fits

Supporting Products

The pipeline-produced supporting products are generally not needed in data analysis. These files are created by intermediate processing steps.

Instrum Level Data product HDU name Pipeline Filename Template
ACIS L1.5 TG Events EVENTS TG1.5 acis*_evt1a.fits
HRC L1.5 TG Events EVENTS TG1.5 hrc*_evt1a.fits
HRC L1.5 TG Source list SRCLIST TG1.5 hrc*_src1a.fits

Last modified: 28 October 2009