Release Notes for ETC 22.1.2

Welcome to ETC 22.1.2. This patch release affects only STIS, and resolves the following issues:

CCD Imaging and Target Acquisition with Binning:
  • Brightest pixel quantities now correctly calculate the area of the brightest binned pixel.
CCD Spectroscopy:
  • Warnings are now correctly generated based on values pertaining to a single read, rather than the total exposure time
Slitted spectroscopy:
  • Throughput plot title for extended target spectroscopy now correctly excludes the slit in the obsmode string
  • The convolution kernel is now correctly computed by rounding to the next highest integer number of pixels
Slitless spectroscopy:
  • Count rates from extended targets whose diameter is greater than the visible area of the detector are no longer overestimated
  • Extraction regions are now correctly rounded up to an integer number of pixels.
CCD Spectroscopy with Spatial Binning:
  • Extraction heights are now correctly rounded up to an integer number of binned pixels for both target and sky.

Release Notes for ETC 22.1.1

Welcome to ETC 22.1.1. This patch release implements a single bugfix that affects only STIS spectroscopy with the e140m echelle. The effects of echelle scattering are now correctly included in the global (total detector) quantities.

Release Notes for ETC 22.1

New Features

Welcome to ETC 22.1. This version of the ETC implements several new features, notably:

General

  • A number of new non-stellar models have been made available
  • The plot buttons now appear at both the top and the bottom of the output page
  • Imaging modes now produce a warning if more than 5% of the target flux occurs outside the filter wavelength specification

ACS

  • The default number of independent exposures for the imaging ETC has been changed to 4
  • Postflash counts are now included in the region total extracted counts, brightest pixel counts, and global background counts for CCD imaging

COS

  • No COS-specific new features in this release.

STIS

  • Echelle slits have been added to the STIS CCD Spectroscopic ETC

WFC3

  • The default extraction region for point sources for the UVIS imaging ETC has been changed to a circular region with a radius of 0.4 arcsec
  • Postflash counts are now included in the region total extracted counts, brightest pixel counts, and global background counts for UVIS imaging

Documentation

  • The input page now contains a link to the redshift documentation

Under the hood

  • Instrument data values have been updated
  • The ETC calculation date was updated to MJD 57112.9, corresponding to the middle of cycle 22, 03-31-2014

Resolved Issues

This version resolves the following issues:

General

  • Stellar models in dropdown menus are now consistently in spectral order
  • Operations involving a spectrum and passband that are entirely disjoint now correctly cause an error, rather than incorrectly issuing a partial overlap warning

ACS

  • Spectroscopic calculations of extended targets now correctly use extraction regions that are rounded up to an integer number of pixels.
  • Global (whole-detector) target rates and counts for the HRC detector now correctly exclude the quantum yield correction for comparison with saturation thresholds.

COS

  • The spectroscopic target acquisition ETC now reports the acquisition mode and the stripe used
  • The imaging and imaging target acquisition pixel sizes were updated to match the values in the instrument handbook

STIS

  • The echelle scattering factor used to estimate the global background rates has been updated
  • The output page row incorrectly titled “First Order Grating” is now titled simply “Grating”
  • Extended targets larger than the detector are now correctly handling in STIS imaging modes
  • The target acquisition ETC no longer generates the CTE warning
  • The Target Acquisition ETC now reports the acquisition mode used
  • Target Acquisition calculations with a slit in place now correctly excludes the effect of slit diffraction losses, and correctly uses the ETC calculation date, when computing the observed background; and correctly shows the distinct target and background throughput curves for point targets observed background.
  • Target Acquisition calculations with a slit in place now correctly use the area of the slit when computing the extraction area (extended targets) or enclosed energy fraction (point targets), and the effect of slits with a width narrower than one pixel is no longer ignored when computing the brightest pixel rate.

WFC3

  • The WFC3 IR spectroscopic ETC now reports the grism used
  • The WFC3 IR ETCs now correctly describe the global background as including contributions from the thermal self-emission
  • Spectroscopic calculations of extended targets now correctly use extraction regions that are rounded up to an integer number of pixels.
  • Global (whole-detector) target rates and counts for the UVIS detector now correctly exclude the quantum yield correction for comparison with saturation thresholds.

Known Issues

Please see the News and Known Issues page for known issues with this release.