HRC Calibration Information

This page contains current and historical documents regarding calibration of Chandra's High Resolution Camera (HRC). Items are organized by topic (see menu on left) and are ordered by date for each topic, with most recent items at the top. For topics with on-going monitoring or calibration (e.g. background, gain correction) the status is summarized at the top of each section.

Please see also these additional resources:

• Proposers' Observatory Guide chapter on HRC
• CIAO data analysis guides for the HRC
• HRC products in the Calibration Database
• Chandra Calibration Review presentations related to the HRC
• HRC-S/LETG Observer Information
• Chandra Data Archive: SPIE papers

Recently updated:

• QE loss attributable to gain drop [Oct 2021]
• HRC-I QE update [Sep 2021]
• HRC-S QE update [Sep 2021]
• HRC-S Gain and LETG background filter [Jun 2020]
• New HRC Monitoring pages [Jan 2020]
• HRC-S QEU update [Jun 2018]
• HRC-S Degap update [Feb 2018]

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Instrument Sensitivity

Effective Area (HRC+HRMA)

• Status: The effective area is the product of the HRMA effective area, the detector Quantum Efficiency (modified by the QE uniformity maps) and the UV Ion-shield filter transmission. The latest versions incorporate the HRMA EA file $CALDB/data/chandra/default/axeffa/hrmaD1996-12-20axeffaN0008.fits. Individual files must be constructed for each observation separately using the CIAO tool mkarf. Nominal on-axis effective areas for the HRC-I and HRC-S may be obtained via the Chandra Effective Area viewer. A time dependence in the HRC-S effective area has been incorporated via time-stamped QEU files. [Aug 2011]
• Memos, reports, and presentations
• LETG+HRC-S Effective Area [Apr 2011]
• Construction of v8 of the HRC-I QE, J. Posson-Brown & V. Kashyap [Oct 2010]
• Effect of new HRMA EA model on HRC-I, J. Posson-Brown & V. Kashyap [Feb 2009]
• Calibration Dependencies for HRC-I effective area, V. Kashyap, J. Drake, et al. [Jan 2009]
• Matrix of components for pre-2010 on-axis effective areas [Jan 2005]
• Effective Area of the AXAF high resolution camera (HRC), D. Patnaude et al. [preflight; c.2000]

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Quantum Efficiency of the Microchannel Plates

• Status: Both the HRC-I and HRC-S QE have been updated in 2021 to account for the recently observed changes in the decline in count rates in monitored sources. Changes to the HRMA EA cause changes to the model parameters of standard sources observed with ACIS-S/HETG and ACIS-S/LETG that are in turn used to calibrate the HRC-S QE and then the HRC-I QE. The files listed here are for nominal on-axis pointings; the QEs will be modified by the QE Uniformity files at other locations on the detector. The files in the CALDB have the UVIS transmission folded in, and thus do not represent the bare QE. [Oct 2021]
• Current products
• HRC-I QE : time-stamped files reflecting the drop in low-energy QE [Sep 2021]
  $CALDB/data/chandra/hrc/qe/hrciD1999-07-29qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2000-07-23qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2001-04-17qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2001-10-12qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2002-04-12qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2002-10-23qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2003-04-23qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2003-10-06qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2004-04-05qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2004-11-05qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2005-05-15qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2005-11-01qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2006-04-25qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2006-11-19qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2007-09-15qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2008-09-11qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2009-09-15qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2010-09-16qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2011-09-29qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2012-09-29qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2013-10-03qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2014-09-29qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2015-08-05qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2016-06-11qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2017-02-16qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2017-08-16qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2018-02-12qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2018-08-24qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2019-02-27qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2019-08-24qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2020-02-20qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2020-08-27qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2021-01-09qeN0013.fits
  $CALDB/data/chandra/hrc/qe/hrciD2021-02-16qeN0013.fits
• HRC-S QE : time-stamped files reflecting different time-dependence regimes [Sep 2021]
  $CALDB/data/chandra/hrc/qe/hrcsD1999-07-22qeN0016.fits
  $CALDB/data/chandra/hrc/qe/hrcsD2012-03-29qeN0016.fits
  $CALDB/data/chandra/hrc/qe/hrcsD2021-05-14qeN0016.fits
• Memos, reports, and presentations
• QE loss attributable to gain drop, V. Kashyap [Oct 2021]
• Chandra/HRC-I Quantum Efficiency vN0012, V. Kashyap & P. Ratzlaff [Jun 2020]
• Chandra/HRC-I Quantum Efficiency vN0011, V. Kashyap & P. Ratzlaff [May 2018]
• Construction of v8 of the HRC-I QE, J. Posson-Brown & V. Kashyap [Oct 2010]
• Cal Presentations: HRC-I QE ; HRC-S QE
• Calibration Dependencies for HRC-S+LETGS QE, V. Kashyap, J. Drake, et al. [Nov 2008]
• Verifying the HRC-I QE and QEU, J. Posson-Brown & V. Kashyap, CCW, 2007.9 [Sep 2007]
• Summary of pre-2010 QE Models (the current QE models are adjustments to the old versions) [2004]
• "An Update to the HRC-I Quantum Efficiency Model" (model v2.2), J. Posson-Brown, R. H. Donnelly, and D. Pease [27 October 2003]
• An Update to the HRC-I MCP Quantum Efficiency, J. Posson-Brown, R.H. Donnelly, & D. Pease, CCW, 2003.37 [Oct 2003]
• "A New Flight Model of the HRC-I MCP Quantum Efficiency" (model v2.1) K. T. Hole, R. H. Donnelly, and J. Posson-Brown [6 August 2002]
• Relative QE as a function of Incident Angle [Jun 2002]
• New Flight Model of the HRC-I MCP Quantum Efficiency, J. Posson-Brown, R.H. Donnelly, & K.T. Hole, CCW, 2002.42 [Nov 2002]
• [SPIE] "In-flight Effective Area Calibration of the Chandra LETGS", D. Pease, et al., 2002, SPIE Proc. 4851, 157
• [SPIE] "Low Energy Effective Area of the Chandra Low Energy Transmission Grating Spectrometer", D. Pease, et al., 2000, SPIE Proc. 4012, 700
• [SPIE] "In-flight Performance and Calibration of the Chandra High Resolution Camera Spectroscopic Readout (HRC-S)", R. Kraft, et al., 2000, SPIE Proc. 4012, 493

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QE uniformity

• Status: The QE varies across the detector, and maps have been generated to correct for such variations and flat-field the response. The approx 0.5%/year decline in the HRC-S effective area is now included via annual time-stamped HRC-S QEU files. Note that the on-axis decline is slightly steeper than the decline off-axis, but is otherwise mostly gray. At some specific locations on the detector (corresponding to 60-90 Å along negative dispersion order and 140-170 Å along positive dispersion order), the EA is further reduced (by less than approx 1%) because of loss of events due to gain sag. [Jun 2018]
• Current products
• HRC-I: $CALDB/data/chandra/hrc/qeu/hrciD1999-07-22qeuN0002.fits [v1.1; Jul 2001]
• HRC-S : [v15; Sep 2021]
  $CALDB/data/chandra/hrc/qeu/hrcsD1999-07-22qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2000-01-01qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2001-01-01qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2002-01-01qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2003-01-01qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2004-01-01qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2005-01-01qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2006-01-01qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2007-01-01qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2008-01-01qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2009-01-01qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2009-08-08qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2010-09-14qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2012-03-29qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2012-10-05qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2013-09-21qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2015-02-17qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2016-02-22qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2016-07-28qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2017-01-23qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2017-06-05qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2017-09-26qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2018-01-19qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2018-05-27qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2018-09-26qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2019-02-24qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2019-08-22qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2020-01-16qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2020-07-22qeuN0015.fits
  $CALDB/data/chandra/hrc/qeu/hrcsD2021-05-14qeuN0015.fits
  
• Memos, reports, and presentations
• HRC-S QEU Time Variability, N. Durham [Aug2011; updated Oct2011]
• Cal Presentations: HRC-I QEU ; HRC-S QEU
• Verifying the HRC-I QE and QEU, J. Posson-Brown & V. Kashyap, CCW, 2007.9 [Sep 2007]
• Flat Field Maps [Jan 2005]
• Summary of QE Models [2004]
• Studying the HRC-I Uniformity with Observations of the Vela SNR, J. Posson-Brown & R.H. Donnelly, CCW, 2004.29 [Oct 2004]
• Improvements to the HRC-S QE uniformity and LETGS effective area, D. Pease, J. Drake, H. Marshall, V. Kashyap, & B. Wargelin, CCW, 2004.2 [Oct 2004]
• Low energy uniformity in the Quantum Efficiency of the HRC-I, R.H. Donnelly, J. Posson-Brown, R. Edgar, T. Gaetz, P. Plucinsky, & R. Smith, CCW, 2002.12 [Oct 2002]
• Relative QE as a function of Incident Angle [Jun 2002]
• Calibration Dependencies for HRC-S+LETGS QE [Nov 2008]
• "An Update to the HRC-I Quantum Efficiency Model" (model v2.2), J. Posson-Brown, R. H. Donnelly, and D. Pease [27 October 2003]
• "A New Flight Model of the HRC-I MCP Quantum Efficiency" (model v2.1) K. T. Hole, R. H. Donnelly, and J. Posson-Brown [6 August 2002]
• HRC-S QEU details [Jun 2002]
• [SPIE] "In-flight Performance and Calibration of the Chandra High Resolution Camera Spectroscopic Readout (HRC-S)", R. Kraft, et al., 2000, SPIE Proc. 4012, 493

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UVIS Filter Transmission

• Status: Since October 2003, the HRC door is not closed during radiation passages. In order to monitor the health of the detector, filter transmissions are regularly checked. Thus far, no degradation has been seen. [Jul 2010]
• Current models (Note: These are not stand-alone CALDB files -- they are included in the CALDB QE files.)
  • HRC-I [v4; Jun 2002]
  • HRC-S : center, thick section ; center, thin section ; wings, thin section ; wings, thick section [v4; Jun 2002]
• Memos, reports, and presentations
• UVIS monitoring with Vega M. Juda [24 Jul 2009]
• Cal presentations
• Current Model Summary and Description [Jun 2005]
• UVIS segments on the HRC-S
• "Monitoring the Optical/UV Transmission of the HRC with Betelgeuse", J. Posson-Brown & V. Kashyap, CXC Memo [Jun 2005]
• "Monitoring the HRC-S UV Rate: Observations of Vega", D. Pease, et al., CXC Memo [May 2005]
• HRC-I response to out of band radiation, M. Zombeck [Mar 1999]
• "Calibration of the UV/Ion Shields for the AXAF High Resolution Camera", G.R. Meehan, et al., 1997, SPIE 3114

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Instrument Performance

Point Spread Function

• Status: The HRC detectors do not have physical pixels; incoming photon locations are computed using a weighted average of the charge collected in adjacent amplifiers. Thus, after proper degap-corrections, fine-grained details can be more easily observed with the HRC. There are three anomalies that haven't yet been incorporated into ChaRT PSF models: one is a well-understood instrumental effect (the "HRC-I ghost") that is mostly eliminated (to ~0.1%) using H-test filtering, another is a 5% anomaly at ~0.8 arcsec that is suspected to be due to unmodeled optics, and the third is a newly discovered effect where consecutive nearby events that follow each other rapidly result in a less accurate determination of their positions and hence contribute to a puffiness of the PSF. [Feb 2011]
• Current Products
• HRC-I [Nov 2000]
  type 1 - $CALDB/data/chandra/hrc/2d_psf/hrci1998-11-052dpsf1N0002.fits
  type 2 - $CALDB/data/chandra/hrc/2d_psf/hrci1998-11-052dpsf2N0002.fits
  type 3 - $CALDB/data/chandra/hrc/2d_psf/hrci1998-11-052dpsf3N0002.fits
  type 4 - $CALDB/data/chandra/hrc/2d_psf/hrci1998-11-052dpsf4N0002.fits
  
• HRC-S [Nov 2000]
  type 1 - $CALDB/data/chandra/hrc/2d_psf/hrcs1998-11-052dpsf1N0002.fits
  type 2 - $CALDB/data/chandra/hrc/2d_psf/hrcs1998-11-052dpsf2N0002.fits
  type 3 - $CALDB/data/chandra/hrc/2d_psf/hrcs1998-11-052dpsf3N0002.fits
  type 4 - $CALDB/data/chandra/hrc/2d_psf/hrcs1998-11-052dpsf4N0002.fits
  
• Memos, reports, and presentations
• Empirical PSF from on-axis HRC-I AR Lac observations V. Kashyap & D. Jerius, 2016 [Sep 2016]
• Simultaneous Chandra/Swift Observations of the RT Cru Symbiotic System V. Kashyap, J. Kennea, & M. Karovska, 2013, HEAD, 126.57 [Apr 2013]
• "Pile-up" Effect on the HRC PSF, M. Juda [Oct 2012]
• Analysis of Chandra PSF feature using ACIS data, V. Kashyap [Oct 2010]
• Chandra's Ultimate Angular Resolution: Studies of the HRC-I Point Spread Function, M. Juda, & M. Karovska, 2010, AAS/HEAD, 11.4011, 2010HEAD...11.4011J [Feb 2010]
• Cal Presentations on Chandra PSF
• Studies of the Point Spread Function of the Chandra High Resolution Camera, M. Juda, & M. Karovska, 2009, CCR, 2009.5 [Sep 2009]
• Off-axis PSFs obtained during ACIS Stowed observations [Dec 2007]
• H-test filtering to remove HRC PSF ghost feature [Feb 2006]
• FWHM data products from XRCF [Jul 2002]

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Spectral Response

• Status: The HRC has a limited spectral discrimination. It is sufficient to distinguish between hard and soft sources, but not for detailed spectral fitting. We have generated spectral response matrices for both the HRC-I and HRC-S to make it possible to use this capability. Sample hardness ratio grids for some common spectral models are shown in Section 7.6 of the HRC chapter of the POG. (Note that these are for use with imaging observations, not gratings observations.) However, because of the poor spectral resolution, the energy grid associated with the PI channels is provided only for guidance and should not be used for filtering of any sort. Analysis should be carried out in channel space as much as possible. [Oct 2010]
• Current products
• HRC-S
• for SAMP-based PI: $CALDB/data/chandra/hrc/rmf/hrcsD1999-07-22samprmfN0001.fits [Oct 2010]
• for PHA-based PI: $CALDB/data/chandra/hrc/rmf/hrcsD1999-07-22rmfN0001.fits [Nov 2006]
• HRC-I
• for SAMP-based PI: $CALDB/data/chandra/hrc/rmf/hrciD1999-07-22samprmfN0001.fits [Dec 2009]
• for PHA-based PI: $CALDB/data/chandra/hrc/rmf/hrciD1999-07-22rmfN0002.fits [Dec 2009]
• Memos, reports, and presentations
• v1 of HRC-S RMF (for SAMP-based PI), V. Kashyap & J. Posson-Brown [Oct 2010]
• v1 of HRC-I RMF (for SAMP-based PI), V. Kashyap & J. Posson-Brown [Dec 2009]
• v1 of HRC-S RMF (for PHA-based PI), V. Kashyap & J. Posson-Brown [Nov 2006]
• v1 of HRC-I RMF (for PHA-based PI), V. Kashyap & J. Posson-Brown [Nov 2005]
• Spectral Response of the HRC-I, V. Kashyap, 2005, CCW 2005.12
• PHA response [June 2002]

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Timing

• Status: There is a wiring error in the HRC that can lead to incorrect times being assigned to events, and causing the timing resolution to be degraded to the inverse of the total event rate. An operating mode called S_TIMING, which activates only the center segment of the HRC-S and disables on-board event filtering, can be used to recover the ~16 microsecond resolution with the HRC-S. [Apr 2003]
• Memos, reports, and presentations
• On the HRC-S Timing Error [Apr 2003]
• "Astronomical Calibration of the Chandra Clock", A.Rots, 2003, CCW 2003.39
• "HRC Science and Calibration", S.Murray, 2002, CCW 2002.6
• "Absolute Time Calibration", A.Rots, 2002, CCW 2002.36
• "HRC Event Time Tag Investigation", M.Juda, CXC Memo [Mar 2001]
• PSR0540-69 Imaging/Timing with HRC-I, S. Murray [Sep 1999]
• HRC Deadtime and Telemetry Saturation, M.Juda & A.Dobrzycki, CXC Memo [Jun 1999]

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Background

• Status: The particle background in the HRC, which had been increasing due to the drop in solar activity, has begun to decrease again; see Fig 1 of Isobe & Juda [Sep 2010]
• Current Products
  • Yearly background spectra obtained from AR Lac observations with HRC-I are now in the CALDB. A CIAO thread that describes how they can be used to filter on PI and reduce background is at https://cxc.harvard.edu/ciao/threads/hrci_bg_spectra/. [Nov 2013]
    $CALDB/data/chandra/hrc/pibgspec/hrciD1999-10-04pibgspecN0001.fits
    $CALDB/data/chandra/hrc/pibgspec/hrciD2000-12-12pibgspecN0001.fits
    $CALDB/data/chandra/hrc/pibgspec/hrciD2002-01-26pibgspecN0001.fits
    $CALDB/data/chandra/hrc/pibgspec/hrciD2003-02-22pibgspecN0001.fits
    $CALDB/data/chandra/hrc/pibgspec/hrciD2004-11-25pibgspecN0001.fits
    $CALDB/data/chandra/hrc/pibgspec/hrciD2005-10-17pibgspecN0001.fits
    $CALDB/data/chandra/hrc/pibgspec/hrciD2006-09-20pibgspecN0001.fits
    $CALDB/data/chandra/hrc/pibgspec/hrciD2007-09-17pibgspecN0001.fits
    $CALDB/data/chandra/hrc/pibgspec/hrciD2008-09-07pibgspecN0001.fits
    $CALDB/data/chandra/hrc/pibgspec/hrciD2009-09-24pibgspecN0001.fits
    $CALDB/data/chandra/hrc/pibgspec/hrciD2010-09-25pibgspecN0001.fits
    $CALDB/data/chandra/hrc/pibgspec/hrciD2011-09-19pibgspecN0001.fits
    $CALDB/data/chandra/hrc/pibgspec/hrciD2012-09-27pibgspecN0001.fits
    $CALDB/data/chandra/hrc/pibgspec/hrciD2013-09-16pibgspecN0001.fits
  • Yearly HRC-I background events, constructed from stowed data, are available in the CALDB as a separate download. A CIAO thread that describes how to use them to get better flat fielding is at https://cxc.harvard.edu/ciao/threads/hrci_bg_events/ and are described in Isobe & Juda (2014) [Jan 2014]
    $CALDB/data/chandra/hrc/bkgrnd/hrciD1999-12-06bkgrndN0001.fits
    $CALDB/data/chandra/hrc/bkgrnd/hrciD2001-01-01bkgrndN0001.fits
    $CALDB/data/chandra/hrc/bkgrnd/hrciD2002-01-01bkgrndN0001.fits
    $CALDB/data/chandra/hrc/bkgrnd/hrciD2003-01-01bkgrndN0001.fits
    $CALDB/data/chandra/hrc/bkgrnd/hrciD2004-01-01bkgrndN0001.fits
    $CALDB/data/chandra/hrc/bkgrnd/hrciD2005-01-01bkgrndN0001.fits
    $CALDB/data/chandra/hrc/bkgrnd/hrciD2006-01-01bkgrndN0001.fits
    $CALDB/data/chandra/hrc/bkgrnd/hrciD2007-01-01bkgrndN0001.fits
    $CALDB/data/chandra/hrc/bkgrnd/hrciD2008-01-01bkgrndN0001.fits
    $CALDB/data/chandra/hrc/bkgrnd/hrciD2009-01-01bkgrndN0001.fits
• Memos, reports, and presentations
• How to Create a Background Map for an Observation, T. Isobe & M. Juda [Jan 2009; updated Jan 2014]
• HRC-I Background PI Spectra, V. Kashyap & J. Posson-Brown [May 2010]
• High Resolution Camera Stowed Background Study, T. Isobe & M. Juda [Jan 2009]
• On-orbit background current status [Jul 2008]
• Background Variability in the Chandra High Resolution Camera, C. Wilton, 2003, CCW 2003.43
• [SPIE] "Characteristics of the On-Orbit Background of the Chandra X-ray Observatory High Resolution Camera", M. Juda, 2002, SPIE 4851, 112
• Time History of the HRC Background, M. Juda, CXC Memo [Mar 2001]
• On-orbit background surface distribution for the HRC-I [Sep 2000]
• On-orbit background rates for the HRC-I [Oct 1999]
• On-orbit background rates for the HRC-S [Oct 1999]
• HRC Response to SXRB, M. Juda, CXC Memo [July 1995]

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Count Rate Linearity

• Nominal count rate correction factors for HRC-I: table ; figure [May 1998]
• Memos, reports, and presentations
• Response of the HRC at high count rates [Jun 2002]
• "Count Rate Linearity of the AXAF High Resolution Camera (HRC)", D. Pease & H. Donnelly, ASC Calibration Memo [May 1998]

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Data Processing

Filtering

• Current Products
  • Event Flatness Test Coefficients
  • HRC-I : $CALDB/data/chandra/hrc/eftest/hrciD1999-07-22eftestN0001.fits [v1; Mar 2000]
  • HRC-S : $CALDB/data/chandra/hrc/eftest/hrcsD1999-07-22eftestN0001.fits [v1; Mar 2000]
  • Event Hyperbolic Test Coefficients
  • HRC-I : $CALDB/data/chandra/hrc/fptest/hrciD1999-07-22fptestN0003.fits [v3; Mar 2001]
  • HRC-S : $CALDB/data/chandra/hrc/fptest/hrcsD1999-07-22fptestN0004.fits [v4; Mar 2001]
  • Status-bit definitions
• Memos, reports, and presentations
• HRC-S Gain Map and LETG Background Filter (2020), B. Wargelin & P. Ratzlaff [Jun 2020]
• New HRC-S Gain Map and LETG Background Filter, B. Wargelin & P. Ratzlaff [Nov 2008]
• Description of status bit and H-test filtering (Describes HRC PSF ghost feature) [Feb 2006]
• [SPIE] "Event Screening for the Chandra X-Ray Observatory High Resolution Camera (HRC)", S. Murray et al, SPIE, 2000

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Degap and Position Corrections

• Status: Because of the manner in which event positions are calculated in the HRC, a gap is left at the midpoints between amplifier taps. These gaps are removed during ground processing using a degapping algorithm that adjusts the location of each event. [Feb 2018]
• Current degap tables
• HRC-I: $CALDB/data/chandra/hrc/gaplookup/hrciD1999-07-22gaplookupN0004.fits [Jun 2012]
• HRC-S: $CALDB/data/chandra/hrc/gaplookup/hrcsD1999-07-22gaplookupN0004.fits [Feb 2018]
• Memos, reports, and presentations
• HRC-S Degap update to reduce plus/minus order line profile mismatch, V. Kashyap, CXC Memo, Feb 2018
• HRC-S Aimpoint Degap Validation, V. Kashyap, CXC Memo, June 2012
• HRC-S Degap Look-up Near the Aim-point, M. Juda, CXC Memo, April 2012
• HRC-I Degap Update (2012), M. Juda, CXC Memo, April 2012
• HRC-S Event Position Errors Near the Aim Point, B. Wargelin, CXC Memo, Feb 2012
• HRC Taps and Degap Maps, B. Wargelin, CXC Memo, Feb 2012
• HRC-I Degap Lookup from Capella Data - 2007, M. Juda, CXC Memo, July 2007
• Cal Presentations (spanning 2002 - 2007)
• Description of Degap Products [Apr 2006]
• Lookup tables [Apr 2006; supersedes all previous formats]
• HRC-S degap [Nov 2005]
• Polynomial corrections [Jun 2005]
• Corrlam: correcting nonlinearities in LETG+HRC-S dispersion relation [Feb 2005]
• [SPIE] Chandra HRC-S Degapping Corrections, V.L. Kashyap, et al., Proc. SPIE 5488-71, 2004
• [SPIE] Update on the Non-Linearities in the Chandra LETG/HRC-S Dispersion Relation, S.M. Chung, et al., Proc. SPIE 5488-62, 2004
• [SPIE] Characterizing nonlinearities in the Chandra LETGS + HRC-S dispersion relation S.M. Chung, et al., Proc. SPIE 5165, 518, 2003
• [SPIE] Improving Chandra High Resolution Camera event positions via corrections to crossed-grid charge detector signals, M. Juda, et al., Proc. SPIE 4140, 155, 2000
• Degap Corrections for HRC-I and HRC-S detectors, A. Kenter, et al., CXC Memo, Oct 1999
• Degap as a Transformation of Probability Distribution Problem, A. Kenter, et al., CXC Memo, Mar 1999
• HRC Degapping Corrections, M. Juda, CXC Memo, Aug 1998
• HRC Position Logic, M. Juda, CXC Memo, July 1996

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Gain Maps

• Status: By default, PI is now calculated from scaled SUMAMPS ("SAMP") instead of PHA. The new gainmaps, listed below, convert SAMP to PI, correcting for the gain declines which have occurred since launch.
  In order to alleviate the gain sag, the HRC-S voltage setting was increased in late March 2012. New gain files that properly account for the changes are available with CALDB v4.5.1+ [Nov 2013]
• Current products
• HRC-I [Nov 2013]
  $CALDB/data/chandra/hrc/gmap/hrciD1998-10-30sampgainN0001.fits
  $CALDB/data/chandra/hrc/gmap/hrciD1999-10-04sampgainN0001.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2000-12-12sampgainN0001.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2002-01-26sampgainN0001.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2003-02-22sampgainN0001.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2004-11-25sampgainN0001.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2005-10-17sampgainN0001.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2006-09-20sampgainN0001.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2007-09-17sampgainN0001.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2008-09-07sampgainN0001.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2009-09-24sampgainN0001.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2010-09-25sampgainN0002.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2011-09-19sampgainN0001.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2012-09-27sampgainN0001.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2013-09-16sampgainN0001.fits
• HRC-S [Nov 2012]
  $CALDB/data/chandra/hrc/t_gmap/hrcsD1999-07-22t_gmapN0002.fits
  $CALDB/data/chandra/hrc/t_gmap/hrcsD2012-03-29t_gmapN0002.fits
• The gain maps listed below are the old maps, used to calculate PI from PHA.
• HRC-I [May 2007]
  $CALDB/data/chandra/hrc/gmap/hrciD1998-10-30gainN0002.fits
  $CALDB/data/chandra/hrc/gmap/hrciD1999-10-04gainN0003.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2000-12-12gainN0002.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2002-01-26gainN0002.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2003-02-22gainN0002.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2004-11-25gainN0002.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2005-10-17gainN0002.fits
  $CALDB/data/chandra/hrc/gmap/hrciD2006-09-06gainN0002.fits
• HRC-S [Jun 2020]
  $CALDB/data/hrc/gmap/hrcsD1999-07-22t_gmapN0003.fits
  $CALDB/data/hrc/gmap/ hrcsD2012-03-29t_gmapN0003.fits
• Memos, reports, and presentations
• Comparing Jupiter's equatorial X-ray emissions with solar X-ray flux over 19 years of the Chandra mission, McEntee, S., et al., JGR: Space Physics 127, e2022JA030971 [Nov 2022; incorporates non-linear HRC-I gain correction]
• HRC-S Gain Map and LETG Background Filter (2020), B. Wargelin & P. Ratzlaff [Jun 2020]
• Chandra Why Topic: HRC-I Gain Maps [Nov 2013]
• HRC-S Voltage Change, B. Wargelin [Jul 2012]
• Cal presentations on HRC-I gain
• Cal presentations on HRC-S gain
• SUMAMPS-based Gain Maps for the HRC-I, J. Posson-Brown & V. Kashyap [Nov 2009]
• HRC-I gain correction: methods and status [Jan 2009]
• New gain map and background filter for HRC-S/LETG [Nov 2008]
• New HRC-S Gain Map and LETG Background Filter, B. Wargelin & P. Ratzlaff [Nov 2008]
• [SPIE] "HRC-I Gain Correction", J. Posson-Brown & V. Kashyap, 2007, SPIE 6686, 26
• HRC-I Gain Correction, J. Posson-Brown & V. Kashyap [Mar 2007]
• Monitoring the HRC-S Gain with the LETG/HRC-S, D. Pease & J. Drake [Oct 2003]
• Evolution of PHA Response in the HRC, J. Posson-Brown & R. H. Donnelly [May 2003]

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Hot/Bad Pixels

• Current products
• HRC-I : $CALDB/data/chandra/hrc/badpix/hrciD1999-07-22badpixN0002.fits [v2; Apr 2002]
• HRC-S : $CALDB/data/chandra/hrc/badpix/hrcsD1999-07-22badpixN0003.fits [v3; Aug 2004]
• Memos, reports, and presentations
• The Imaging and Spectral Performance of the HRC, V. Kashyap & J. Posson-Brown, 2009, CCR 2009.14 [Sep 2009]
• Status of HRC bad pixel maps [Oct 2004]
• Description of HRC-S bad pixel map [Jun 2004]
• Description of HRC-I bad pixel map [Mar 2002]

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Miscellaneous

• HRC Science Instrument modes (SI modes), D. Patnaude [Jan 2018]
• Mike Juda's CXC Memos [Jan 2011]
• Instrument Timeline [June 2009]
• Various HRC calibration information from Charlie Wilton's webpage [Nov 2001]
• HRC-I Plate Focus Analysis, L. David, O. Johnson, E. Beckerman [Sep 1999]
• Analysis of Un-de-dithered Focus Plates, D. Jerius [Sep 1999]

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Geometry

• Images
  • Instrument Layout
  • UVIS segments on HRC-S
• Memos, reports, and presentations
• Clocking angle and detector geometry inconsistencies 2: LETG with HRC-I and ACIS-I, J. Drake & P. Ratzlaff [Dec 2002]
• Clocking angle and detector geometry inconsistencies in telD1997-07-23geomN004.fits, J. Drake & P. Ratzlaff [Nov 2002]
• Locating the HRC Shutters, H. Donnelly [Aug 1999]
• HRC-S Coordinate Mapping, M. Juda [Feb 1999]

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Monitoring

• Monitoring Dosage on both HRC-I and HRC-S, by T. Isobe [updated monthly]
• Monitoring Vega for health of UVIS, by T. Isobe [updated continuously]
• Monitoring HZ 43 for low-energy gain and QE, by T. Isobe [updated continuously]
• Monitoring AR Lac for gain and PSF, by T. Isobe [updated continuously]
• Older pages:
  • UVIS monitoring of Vega, M. Juda [Oct 2012]
  • HRC-I QE, J. Posson-Brown [Feb 2009]
  • HRC-I Gain, J. Posson-Brown [Oct 2012]
  • HRC-S QE, J. Posson-Brown [Apr 2009]
  • HRC-S Gain, J. Posson-Brown [Dec 2009]

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Ground Calibration

• Memos, reports, and presentations
• HRC Instrument PI team page: Pre-flight calibration information
• Summary of SAO and XRCF analysis by Instrument PI team
• PSF FWHM data products [XRCF; Jul 2002]
• Summary of BND Analysis [XRCF; Jun 2002]
• Response of the HRC at high count rates [XRCF; Jun 2002]
• "Spectral Fitting of HXDS Beam Normalization Detectors: Results for HRC Tests (Phase G)", D. Patnaude, D. Pease & H. Donnelly, CXC Memo [Apr 1998]
• [SPIE] "Performance and Calibration of the AXAF High Resolution Camera I: Imaging Readout", A.T. Kenter et al, SPIE, 1997
• [SPIE] "Performance and Calibration of the AXAF High Resolution Camera II: the Spectroscopic Detector", R.P. Kraft et al, SPIE, 1997
• [SPIE] "The AXAF High Resolution Camera (HRC): Calibration and Recalibration at XRCF and Beyond", S.S. Murray et al, SPIE, 1997
• Modeling of the HRC Readout System, K. Flanagan, AXAF Memo, Sep 1992

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Contributors:
HRC IPI Team
CXC Calibration Team

Comments to cxccal (at) cfa.harvard.edu