Hubble Space Telescope Primer for Cycle 17

4.7 Additional Observing Modes

4.7.1 Imaging Polarimetry

ACS/WFC and ACS/HRC provide imaging polarimetry at 0^o, 60^o, and 120^o relative polarization angles. NICMOS/NIC1 provides imaging polarimetry from 800 - 1300 nm and NIC2 provides imaging polarimetry from 1900 - 2100 nm, both with 0^o, 120^o, and 240^o relative polarization angles. WFC3, STIS and COS do not have a polarimetric capability.

4.7.2 Slitless Imaging Spectroscopy

In the ultraviolet, <350 nm, there are a number of choices. ACS/SBC has two prisms providing R ~ 100 spectroscopy (at 121 nm) from 115-170 nm. The ACS/HRC prism provides R ~ 100 spectroscopy (at 200 nm) from 170 - 400 nm. The WFC3/UVIS has a grism for R ~ 70 spectroscopy from 200 - 400 nm, and the STIS/NUV has a prism covering the range 115 - 300 nm with R ~ 2500 to 10. In addition, any 1st order STIS mode can be used for large aperture slitless spectroscopy over a 52"x52" FOV (STIS CCD gratings) or a 25"x25" FOV (STIS MAMA 1st order gratings).

In the optical, 350 - 1000 nm, the WFC3/UVIS has a grism covering 200 - 400 nm, and R ~ 70; while ACS/WFC and HRC cover 550 - 1050 nm with a grism at R ~100.

In the near-infrared, 800 - 2500 nm, WFC3/IR has a grism with R ~ 210 covering 800 - 1150 nm, and a grism with R ~ 130 covering 1100 - 1700 nm. NICMOS/NIC3 has three grisms with R ~ 200 to cover the wavelength region from 800 to 2500 nm in three sections.

Ramp Filters: ACS has a set of ramp filters covering the wavelength range 310 - 1071 nm at 2% and 9% bandwidth. There are five ramp units which each have an inner, middle, and outer segments. The ACS/WFC can use all three segments, providing 15 ramp filters, while the HRC can only use the 3 middle ramp filters.

Quad Filters: WFC3/UVIS contains 5 quad filters. Each is a 2 x 2 mosaic of filter elements with each quadrant providing a different bandpass for narrow band line or continuum measurement.

4.7.3 Coronagraphy

ACS/HRC provides aberrated beam coronagraphy from 200 - 1100 nm, using 1.8" and 3.0" diameter occulting spots. NICMOS/NIC2 provides corrected beam coronagraphy through a 0.8" effective diameter occulting hole. WFC3 does not have a coronagraphic capability. STIS aperture bars allow spectroscopic coronagraphy.

4.7.4 Observations with Two Instruments - Parallel Observing

We encourage observers to submit programs that make use of simultaneous observations with two or more cameras.þThis can greatly increase the scientific value of individual programs and the public archive. There are two ways to obtain parallel observations.þ

Coordinated Parallels:

As the name implies, coordinated parallel observations afford the individual observer the ability to use multiple instruments simultaneously and in a way that optimizes the telescope pointingþ(e.g. -þdither patterns or mosaicing) and exposure and readout times to satisfy the goals of both the primary and parallel science components of a single science program.þ

Pure Parallels:

Pure Parallel observations are proposed independent of any primary GO science program andþ are slightly more restrictive in the number of allowed parallel/primary instrument combinations than are coordinated parallels.þThisþapproach to pure parallel observing, which is new for Cycle 17,þwill identify the parallel scheduling opportunities that are inherent to the accepted set of primary COS spectrographic observations for the cycle.þAccepted WFC3 and/or ACS pure parallel observations are then matched and structured to schedule simultaneously with those COS primary observations. The matching and structuring of parallel to prime observations at the start of the observing cycle is intended to improve the execution rate for all accepted pure parallel programs.þ

Policies and Procedures:

The policies for coordinated and pure parallel observing, including allowed instrument usage, are found in the Cycle 17 Call for Proposals.

The detailed descriptions of the coordinated and pure parallel observing modes, guidelines for developing a proposal using these modes, and how they are implemented and scheduled are found in the Parallel Observations User Information Report (UIR-2004-03) and the individual instrument handbooks.