The Horsehead Nebula in Infrared
The Wide Field Camera 3 (WFC3) is a fourth-generation UVIS/IR imager aboard the Hubble Space Telescope (HST). WFC3 was installed in May 2009 during HST servicing mission 4, and replaces the Wide Field Planetary Camera 2 (WFPC2).
The UVIS and IR Channels are operating nominally.
Late Breaking News from the Last 45 Days
Workaround for aXe issues on astroconda: Click Here
On June 15, 2017, 18 bias files, 4 post-flash files, and 1 image photometry table for WFC3/UVIS were delivered to the Calibration Reference Data System (CRDS) and went live in the 2017.2 release of the MAST processing pipeline for WFC3. These files will be used for processing all WFC3/UVIS data. Please check the [WFC3 reference file pages] and the [WFC3 Photometry website] for more information.
Documents added in the last 45 days
ISR 2017-22: WFC3 Anomalies Flagged by the Quicklook Team
C.M. Gosmeyer & The Quicklook Team 08 Sept 2017
WFC3 STAN Issue 26, December 2017
1. STScI at the AAS 231: January 2018, Washington, D.C.
2.WFC3 Help Desk Changes - New Web Portal Live
3. Geometric Distortion Solution Updates for Medium Band UVIS Filters
4. LINEAR: A Novel Algorithm for Reconstructing Slitless Spectroscopy from HST/WFC3
5. Aligning HST Images to Gaia Catalogs
6. Photometric Repeatability of Spatial Scans with WFC3/UVIS
7. New Documentation
C.Martlin 20 Dec 2017
ISR 2017-24: A Predictive WFC3/IR Dark Current Model
The dark current in the WFC3/IR detector has remained stable at 0.021 DN/s (0.049 e-/s) since launch; there are no long term increases or decreases (Sunnquist et al., 2017). However, image-to-image variations in the full-frame dark current levels as high as 0.014 DN/s (0.032 e-/s) exist that have yet to be explained (Sunnquist et al., 2017; Hilbert & Petro, 2012). These variations limit the accuracy of the dark calibration carried out by the calwf3 pipeline. In an attempt to address this issue, we have examined the relationships of hundreds of HST telemetry parameters to the dark current level. We nd that the dark variations depend on where HST is in relation to the Sun and that the rate of change of certain telemetry parameters, such as the input voltage to WFC3 and the IR detector electronics board temperature, throughout this day/night cycle correlate with the IR dark rate. Using reference pixel and input voltage information, we construct a full-frame WFC3/IR dark current model capable of predicting the dark rate in WFC3/IR observations. Tests show that this model reduces the error in the mean dark rate by more than a factor of two compared to the current superdark calibration method carried out by the calwf3 pipeline; however, the shape of the dark current image is calibrated similarly using either of these calibration methods.
Ben Sunnquist, Sylvia Baggett & Knox S. Long 11 Dec 2017 (pdf)
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