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Updates to the RMF model in the ACIS FI CCDs

A. Vikhlinin, 03/22/04

This memo describes two updates to the RMF model in the ACIS FI chips:

  1. Additional exponential tail in the pre-CTI response
  2. New model to the CTI scatter matrix obtained without add_cti.pro

PDF file


Caveats, Limitations, Error analysis
R. Edgar, 12/16/2001, (mailto:edgar@head-cfa.harvard.edu)

ACIS-I, S2(FI) Release Notes

We present a new release of ACIS response products for the ACIS extended imaging array front-side devices (chips I0, I1, I2, I3, and S2). These products are a part of CALDB release 2.18, and are for use with the CXC implementation of the charge transfer inefficency (CTI) correction software in the new revision of acis_process_events released with ciao 2.3. They should be used with data taken at -120oC (which includes nearly all data taken since 2000 January 31).

These products were tested against data from the onboard external calibration source (ECS) taken in the spring of 2000, and against astrophysical sources (mainly the supernova remnant 1E0102-72.3) from calendar year 2000.

The gains and line widths are accurate at energies from 1.5 to 6 keV. The gains in nearly every case to 0.3% or better, and the line widths to better than an ADU.

There remain systematic residuals in our E0102 fits at low energies (0.5-1.2 keV). Gain shifts of approximately 0.5-1% are not uncommon, and there may be issues with the line widths and/or astrophysical assumptions that went into the analysis.

S3 Release Notes

This document describes the new (August, 2001) release of ACIS response products (FEF, Fits Encoded Function, and gain files) for the back-illuminated (BI) chip S3 at a focal plane temperature of -120 C, which has been the default operating temperature since January 2000.

Last modified: 11/15/10

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