10.1 Introduction to ACS
HST observations with ACS are specified using the Astronomer's Proposal Tool (APT), and this article provides instructions for completing those observations.
Boldface type indicates the name of an APT parameter or a value for a parameter.
Black text indicates an important note.
Magenta text indicates available but unsupported parameters (requires prior approval from STScI).
Red text indicates restricted parameters (for STScI use only).
Brown text indicates text file parameters.
Items in brackets - <value> - are required values.
Items in square brackets - [<value>] - are optional.
The Instrument Configurations and Operating Modes described in this chapter are used for the Visit and Exposure Specifications. The legal Visit and Exposure Specifications entries are discussed in the following sections. More complete descriptions of Instrument Configurations, Modes, Apertures, Spectral Elements, etc. are available in the ACS Instrument Handbook.
Many of the Optional Parameters have default values. In such cases an Optional Parameter entry in these Specifications is necessary only if it is desired to override the default value. In the STScI proposal system, the physical units of Optional Parameter quantities are always implicit and should never be entered by the observer.
The following tables list the permitted Instrument Configurations, Operating Modes, Apertures, Spectral Elements, and Optional Parameters for the ACS.
Table 10.1: Supported Instrument Parameters for the ACS
|Config.||Mode||Aperture||Spectral Elements||Optional Parameters|
Version Cycle 26 October 2018
Initial Conversion HST Cycle 25 Phase II Proposal Instructions (Engineering) Version Cycle 25 (June 2018)