Space Telescope Science Institute   7.1 Designing an ACS Observing Proposal  7.1.2 Use of Available-but-Unsupported Capabilities

7.1.1 Identify Science Requirements and Define ACS Configuration


First and foremost, of course, you must identify the science you wish to achieve with ACS. Basic decisions you will need to make are:

As you choose your science requirements and work to match them to the instrument's capabilities, keep in mind that those capabilities differ greatly depending on whether you are observing in the optical or near-UV with the CCD, or in the far-UV using the MAMA detector. Trade-offs are described in Table 7.1

Table 7.1: Science decision guide.
Decision
Choices
Tradeoffs
Field of view
Camera
Filter selection
WFC: 202 x 202 arcseconds
HRC: 29 x 26 arcseconds
SBC: 35 x 31 arcseconds
Spectral response
Camera
Filter selection
WFC: 3700-11,000 Å
HRC: 2000-11,000 Å
SBC: 1150-1700 Å
Spatial resolution
Camera
WFC: ~50 milliarcsecond pixels
HRC: ~ 27 milliarcsecond pixels
SBC: ~32 milliarcsecond pixels
Filter selection
Camera
WFC: broad, medium & narrow band, ramps
HRC: Visible, UV, ramp middle sections
Spectroscopy
Camera
Spatial resolution
Field of view
Wavelength range
Grism (G800L): WFC and HRC
Prism (PR200L): HRC
Prism (PR110L, PR130L): SBC
Polarimetry
Filters
UV polarizers combine with Wheel 2 filters
VIS polarizers combine with Wheel 1 filters
Coronagraphy
Filter selection
Coronagraphic imaging available with HRC only
.

Imaging

For imaging observations, the base configuration is detector (Configuration), operating mode (MODE=ACCUM), and filter. Chapter 5 presents detailed information about each ACS imaging mode.

Special Uses

We refer you to Chapter 6 if you are interested in any of the following special uses of ACS: slitless spectroscopy, polarimetry, and coronagraphy.


 7.1 Designing an ACS Observing Proposal  7.1.2 Use of Available-but-Unsupported Capabilities
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