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Last modified: 26 October 2016

URL: http://cxc.harvard.edu/ciao/data_products_guide/index.html

Data Products Guide


The Data Products Guide describes the contents and purpose of the Chandra data products used in data analysis.

For a more general overview of the Chandra data products, refer to the Introduction to the Data Products thread.


ACIS

Primary Products

The data products are rearranged such that the files necessary for most analyses are in the primary directory.

Filename Description Content Instrument SDP Level
acis_evt2.fits imaging event file EVT2 ACIS L2
acis_evt2.fits grating event file EVT2 ACIS L2
acis_cntr_img2.fits high-resolution image of the center of the field HIRESIMG ACIS L2
acis_full_img2.fits full-field sky image LORESIMG ACIS L2
acis_pha2.fits grating spectra SPECTRUM ACIS L2
acis_src2.fits [removed in DS 8.4] imaging source list SRC ACIS L2
acis_bpix1.fits bad pixel list BADPIX ACIS L1
acis_fov1.fits field of view FOV ACIS L1
pcad_asol1.fits aspect solution ASPSOL PCAD L1
orbit_eph1.fits orbit ephemeris ORBITEPHEM1 ORBIT L1

Secondary Products

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

Filename Description Content Instrument SDP Level

† Most users will never need this file in their analysis.

acis_evt1.fits event file EVT1 ACIS L1
acis_flt1.fits good time intervals GTI ACIS L1
acis_mtl1.fits mission timeline MTL ACIS L1
acis_bias0.fits bias maps BIAS0 ACIS L0
acis_pbk0.fits parameter block PBK ACIS L0
acis_stat1.fits † exposure statistics EXPSTATS ACIS L1
acis_msk1.fits detector mask MSK ACIS L1
acis_soff1.fits † [removed in DS 8.4] alignment offsets ALIGNMOFFS ACIS L1
acis_aoff1.fits † [removed in DS 8.4] aspect offsets ASPOFFS ACIS L1
pcad_aqual1.fits † aspect quality ASPQUAL PCAD L1
pcad_osol1.fits † on-board-computer (OBC) aspect solution OBCSOL PCAD L1
solar_eph1.fits † solar ephemeris SOLAREPHEM1 SOLAR L1
lunar_eph1.fits † lunar ephemeris LUNAREPHEM1 LUNAR L1
angles_eph1.fits † viewing angles ANGLEEPHEM Angles L1

Supporting Products

The pipeline-produced supporting products are generally not needed in data analysis.

Filename Description Content Instrument SDP Level
acis_evt1a.fits grating event file TGEVT1 ACIS L1.5
acis_src1a.fits grating source list TGSRC ACIS L1.5

HRC

Primary Products

The data products are rearranged such that the files necessary for most analyses are in the primary directory.

Filename Description Content Instrument SDP Level
hrc_evt2.fits imaging event file EVT2 HRC L2
hrc_evt2.fits grating event file EVT2 HRC L2
hrc_cntr_img2.fits high-resolution image of the center of the field HIRESIMG HRC L2
hrc_full_img2.fits full-field sky image LORESIMG HRC L2
hrc_pha2.fits grating spectra SPECTRUM HRC L2
hrc_src2.fits [removed in DS 8.4] imaging source list SRC HRC L2
hrc_dtf1.fits dead time factor DTF HRC L1
hrc_fov1.fits field of view FOV HRC L1
pcad_asol1.fits aspect solution ASPSOL PCAD L1
orbit_eph1.fits orbit ephemeris ORBITEPHEM1 ORBIT L1

Secondary Products

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

Filename Description Content Instrument SDP Level

† Most users will never need this file in their analysis.

hrc_evt1.fits event file EVT1 HRC L1
hrc_std_flt1.fits good time intervals GTI HRC L1
hrc_bpix1.fits bad pixel list BADPIX HRC L1
hrc_msk1.fits detector mask MSK HRC L1
hrc_mtl1.fits mission timeline MTL HRC L1
hrc_std_dtfstat1.fits † dead time factor statistics DTFSTATS HRC L1
hrc_soff1.fits † [removed in DS 8.4] alignment offsets ALIGNMOFFS HRC L1
hrc_aoff1.fits † [removed in DS 8.4] aspect offsets ASPOFFS HRC L1
pcad_aqual1.fits † aspect quality ASPQUAL PCAD L1
pcad_osol1.fits † on-board-computer (OBC) aspect solution OBCSOL PCAD L1
solar_eph1.fits † solar ephemeris SOLAREPHEM1 SOLAR L1
lunar_eph1.fits † lunar ephemeris LUNAREPHEM1 LUNAR L1
angles_eph1.fits † viewing angles ANGLEEPHEM Angles L1

Supporting Products

The pipeline-produced supporting products are generally not needed in data analysis.

Filename Description Content Instrument SDP Level
hrc_evt1a.fits grating event file TGEVT1 HRC L1.5
hrc_src1a.fits grating source list TGSRC HRC L1.5

Last modified: 26 October 2016
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