Release Notes for ETC 32.1

New Features

Welcome to ETC 32.1, released in December 2023.

This version includes a few small bugfixes along with data updates.

General

• The ETC evaluation date was updated to 2025-Apr-01 (MJD 60766).
• The version of one HST standard star spectrum (P330E) in CALSPEC was incremented. (HETC-732)

ACS

• ACS/SBC throughputs were updated based on new time-dependent sensitivity measurements. (HETC-728, RFD-1641)
• ACS/WFC throughputs were updated to the new default evaluation date, but the underlying Time-Dependent Sensitivity remains the same. (HETC-728, RFD-1625)
• ACS/WFC background warnings are now triggered when background is <30 e-/pixel rather than <20 e-/pixel. (HETC-754)

COS

• COS FUV and NUV (except G285M) throughputs were updated based on new time-dependent sensitivity measurements. (HETC-729, RFD-1640)
• The COS/FUV dark rates for spectroscopic modes have changed for [FUVA, FUVB] from [3.83e-6, 4.93e-6] to [3.39e-6, 4.21e-6] cts/s/pix. (HETC-729)
• The COS/FUV dark rates for target acquisition modes have changed for [FUVA, FUVB] from [7.10e-6, 7.88e-6] to [6.23e-6, 7.01e-6] cts/s/pix. (HETC-729)
• The pull-down display string for COS Spectroscopy FUV/G140L/c800 was updated with slightly more conservative wavelength ranges. (HETC-771)

STIS

• Throughputs were updated to the new default evaluation date, but the underlying Time-Dependent Sensitivity remains the same. (HETC-730, RFD-1632)
• The CCD dark rate for [low, medium, high] changed from [0.026, 0.031, 0.037] to [0.026, 0.032, 0.038] cts/s/pix. (HETC-730)
• The NUV dark rate updated from 0.0020 cts/s/pix to 0.0013 cts/s/pix. (HETC-730)
• Clarified the output text label for sky area. (HETC-721)

WFC3

• The WFC3/UVIS dark rates have changed for [UVIS1, UVIS2] from [2.76e-3, 2.71e-3] to [3.19e-3, 3.33e-3] cts/s/pix. (HETC-731)

Documentation

• Updated dark rates and other scalars in the User’s Guide. (HETC-744)
• Clarified dark current units.

Under the Hood

• No change

Resolved Issues

• No change

Known Issues

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