Table of Contents

Acknowledgments

Chapter 1: Introduction

1.1 Overview

1.2 Introduction to the Handbook

1.2.1 Document Conventions

1.2.2 Examples Used in this Handbook

1.3 Handbook Layout

1.4 Proposal Preparations and Observations with STIS

1.4.1 The STIS Team at STScI

1.5 The Help Desk at STScI

1.6 The STIS Web Pages and Support Information

1.7 Non-proprietary STIS Data

Chapter 2: Special Considerations
for Cycle 20

2.1 STIS Repair and Return to Operations

2.2 Summary of STIS Performance Changes Since 2004

2.3 Use of Available-but-Unsupported Capabilities

2.4 Should I Use COS or STIS?

2.5 Scheduling Efficiency and Visit Orbit Limits

2.6 MAMA Scheduling Policies

2.7 Prime and Parallel Observing: MAMA Bright
Object Constraints

2.8 STIS Snapshot Program Policies

Chapter 3: STIS Capabilities, Design,
Operations, and Observations

3.1 Instrument Capabilities

3.2 Instrument Design

3.2.1 Detectors

3.2.2 STIS Physical Configuration

3.3 Basic Instrument Operations

3.3.1 Typical STIS Observing Sequence

3.4 Designing STIS Observations

3.4.1 Identify Science Requirements and Define
STIS Configuration

3.4.2 Determine Exposure Time and Check Feasibility

3.4.3 Identify Need for Non-Science Exposures
and Constraints

3.4.4 Determine Total Orbit Request

Chapter 4: Spectroscopy

4.1 Overview

4.1.1 Throughputs

4.1.2 Limiting Magnitudes

4.1.3 Saturation

4.1.4 MAMA Bright Object Limits

4.1.5 Scanned Gratings: Prime and Secondary
(Tilt) Positions

4.1.6 Cross-Over Regions

4.2 First-Order Long-Slit Spectroscopy

4.2.1 Gratings for First-Order Spectroscopy

4.2.2 Slits for First-Order Spectroscopy

4.2.3 STIS Pseudo-Aperture Positions

4.2.4 Detailed First-Order Spectroscopic Information

4.3 Echelle Spectroscopy in the Ultraviolet

4.3.1 Echelle Gratings

4.3.2 Slits for Echelle Spectroscopy

4.3.3 Detailed Echelle Information

4.4 Objective Prism Spectroscopy

Chapter 5: Imaging

5.1 Imaging Overview

5.1.1 Caveats for STIS Imaging

5.1.2 Throughputs and Limiting Magnitudes

5.1.3 Signal-To-Noise Ratios

5.1.4 Saturation

5.2 Optical CCD Imaging

5.2.1 Unfiltered (Clear) CCD Imaging: 50CCD & 50CORON

5.2.2 Optical Longpass: F28X50LP

5.2.3 [O III]: F28X50OIII

5.2.4 [O II]: F28X50OII

5.3 Ultraviolet Imaging with the MAMA Detectors

5.3.1 Bright Object Limits

5.3.2 Optical Performance

5.3.3 Unfiltered (Clear) MAMA Imaging: 25MAMA

5.3.4 FUV Red Leak

5.3.5 Longpass-Filtered MAMA Imaging: F25SRF2
and F25QTZ

5.3.6 MAMA Narrow-Band-Filtered Imaging

5.4 Neutral Density Filters

Chapter 6: Exposure Time Calculations

6.1 Overview

6.1.1 The STIS Exposure Time Calculators

6.2 Determining Count Rates from Sensitivities

6.2.1 Spectroscopy

6.2.2 Imaging

6.3 Throughput and Sensitivity

6.4 Computing Exposure Times

6.4.1 Calculating Exposure Times for a Given
Signal-to-Noise

6.5 Detector and Sky Backgrounds

6.5.1 Detector Backgrounds

6.5.2 Sky Background

6.6 Tabular Sky Backgrounds

6.7 Extinction Correction

6.8 Exposure Time Examples

6.8.1 Spectroscopy of Diffuse Source (M86)

6.8.2 Spectroscopy of Solar-Analog Star P041-C

6.8.3 Extended Source with Flux in cgs Units (NGC 6543):
Imaging and Spectroscopy

6.8.4 Echelle Spectroscopy of a Bright Star with Large
Extinction (Sk –69° 215)

6.8.5 Imaging a Faint Stellar Source

6.8.6 Time-Tag Observations of a Flare Star (AU Mic)

Chapter 7: Feasibility and Detector
Performance

7.1 STIS Detectors

7.2 The CCD

7.2.1 Detector Properties

7.2.2 Effects of the Change to STIS Side-2 Electronics
on CCD Performance

7.2.3 STIS CCD Performance After Repair During SM4

7.2.4 CCD Spectral Response

7.2.5 CCD Sensitivity

7.2.6 CCD Long Wavelength Fringing

7.2.7 Fringing Due to the Order Sorter Filters

7.2.8 Optical Performance

7.2.9 Readout Format

7.2.10 Analog-to-Digital Conversion: Selecting
the CCDGAIN

7.3 CCD Operation and Feasibility Considerations

7.3.1 CCD Dark Current

7.3.2 CCD Saturation

7.3.3 CCD Shutter Effects

7.3.4 Cosmic Rays

7.3.5 Hot Pixels

7.3.6 CCD Bias Subtraction and Amplifier Non-Linearity

7.3.7 Charge Transfer Efficiency

7.3.8 Mitigation of CTE Loss for Long-Slit Spectroscopy

7.3.9 Ultraviolet Light and the STIS CCD

7.4 The MAMA Detectors

7.4.1 MAMA Properties

7.4.2 MAMA Spectral Response

7.4.3 MAMA Sensitivity

7.4.4 Optical Performance

7.5 MAMA Operation and Feasibility Considerations

7.5.1 MAMA Saturation—Overflowing the 16 Bit Buffer

7.5.2 MAMA Darks

7.5.3 MAMA Signal-to-Noise Ratio Limitations

7.5.4 MAMA Non-linearity

7.6 MAMA Spectral Offsetting

7.7 MAMA Bright Object Limits

7.7.1 Overview

7.7.2 Observational Limits

7.7.3 How Do You Determine if You Violate a Bright
Object Limit?

7.7.4 Policy and Observers’ Responsibility in Phase I
and Phase II

7.7.5 Policy on Observations That Fail Because they
Exceed Bright Object Limits

7.7.6 What To Do If Your Source is Too Bright for
Your Chosen Configuration?

7.7.7 Bright Object Protection for Solar System
Observations

Chapter 8: Target Acquisition

8.1 Introduction

8.1.1 Initial Pointing

8.1.2 Acquisitions

8.1.3 Peakups

8.1.4 Drift Rates

8.2 STIS Onboard CCD Target Acquisitions (ACQ)

8.2.1 How it Works

8.2.2 Target Location Algorithms

8.2.3 Selecting Target Acquisition Parameters

8.2.4 Specifying Acquisitions in Phase II

8.2.5 Solar System Acquisitions

8.3 Onboard Target Acquisition Peakups
(ACQ/PEAK)

8.3.1 Selecting Peakup Parameters

8.3.2 Specifying Acquisition Peakups in Phase II

8.4 Determining Coordinates in the Guide Star Selection System (GSSS) Reference Frame

8.5 Acquisition Examples

8.5.1 Point Source Acquisition of an Isolated Object

8.5.2 Point Source Acquisition of Bright, Isolated Object
with CCD Dispersed Light Peakup

8.5.3 Diffuse Source Acquisition of a Spiral Galaxy

8.5.4 Point Source Acquisition in a Crowded Field

8.5.5 Point Source Acquisition of a QSO with Fuzz Behind
the Fiducial Bar

8.5.6 Point Source Acquisition of a Bright, Isolated Star
Into the Wedge

8.6 STIS Post-Observation Target Acquisition
Analysis

8.6.1 Did the Acquisition Succeed?

Chapter 9: Overheads and Orbit-Time
Determination

9.1 Overview

9.2 STIS Exposure Overheads

9.3 Orbit Use Determination Examples

9.3.1 Sample Orbit Calculation 1: Long-Slit Spectroscopy of the Galaxy M86

9.3.2 Sample Orbit Calculation 2: Low Dispersion Spectroscopy of Solar Analog

Star P041-C

9.3.3 Sample Orbit Calculation 3: Imaging and Spectroscopy
of the Cat’s Eye Planetary Nebula, NGC 6543

9.3.4 Sample Orbit Calculation 4: MAMA Echelle Spectroscopic Exposures in the CVZ

9.3.5 Sample Orbit Calculation 5: Faint CCD Imaging

Chapter 10: Summary and Checklist

10.1 Phase I Proposing

10.1.1 Phase I Orbit Allocation Examples

10.2 Phase II—Scheduling Approved Observations

Chapter 11: Data Taking

11.1 Basic Operating Modes

11.1.1 CCD ACCUM Mode

11.1.2 MAMA ACCUM Mode

11.1.3 MAMA TIME-TAG Mode

11.2 Exposure Sequences and Contemporaneous Calibrations

11.2.1 Auto-Wavecals

11.2.2 CR-SPLIT

11.2.3 Fringe Flat Fields

11.2.4 Repeat Exposures

11.3 Patterns and Dithering

11.3.1 STIS Imaging Patterns

11.3.2 STIS Spectroscopic Patterns

11.3.3 Generic Patterns

11.3.4 Combining Patterns

11.3.5 Dither Strategies

11.4 Fixing Orientation on the Sky

Chapter 12: Special Uses of STIS

12.1 Slitless First-Order Spectroscopy

12.2 Long-Slit Echelle Spectroscopy

12.3 Time-Resolved Observations

12.4 Observing Too-Bright Objects with STIS

12.5 High Signal-to-Noise Ratio Observations

12.5.1 Dithering

12.5.2 FP-SPLIT Slits for Echelle Observations

12.6 Improving the Sampling of the Line
Spread Function

12.7 Considerations for Observing Planetary Targets

12.7.1 Long-Slit Spectroscopy

12.8 Parallel Observing with STIS

12.8.1 Coordinated Parallels: Using STIS in Parallel
with Other Instruments

12.9 Coronagraphic Spectroscopy

12.10 Coronagraphic Imaging—50CORON

Chapter 13: Spectroscopic
Reference Material

13.1 Introduction

13.2 Using the Information in this Chapter

13.2.1 Wavelength Ranges

13.2.2 Grating Sensitivities and Throughputs

13.2.3 Signal-To-Noise Plots

13.2.4 Plate Scales

13.2.5 Apertures

13.2.6 Fiducials on Bars

13.2.7 Spatial Profiles

13.2.8 Line Spread Functions (Instrumental Profiles)

13.3 Gratings

13.4 Apertures

13.5 Spatial Profiles

13.6 Line Spread Functions

13.7 Spectral Purity, Order Confusion, and Peculiarities

13.7.1 Recommendations for Stellar Observations
with Narrow Slits

13.7.2 Order Overlap and Scattered Light for Echelle
Gratings

13.7.3 Spectroscopic Mode Peculiarities

13.7.4 Railroad Tracks

13.8 MAMA Spectroscopic Bright Object Limits

Chapter 14: Imaging Reference Material

14.1 Introduction

14.2 Using the Information in this Chapter

14.2.1 Sensitivity Units and Conversions

14.2.2 Signal-To-Noise

14.2.3 Point Spread Functions

14.3 CCD

14.26 NUV-MAMA

14.70 FUV-MAMA

14.99 Image Mode Geometric Distortion

14.100 Spatial Dependence of the STIS PSF

14.101 MAMA Imaging Bright Object Limits

Chapter 15: Overview of Pipeline
Calibration

15.1 Pipeline Processing Overview

15.2 How Phase II Parameter Choices Affect Calibration

15.3 More Detailed Information

Chapter 16: Accuracies

16.1 Summary of Accuracies

Chapter 17: Calibration Status and Plans

17.1 Introduction

17.2 Ground Testing and Calibration

17.3 SMOV2 Testing and Calibration

17.4 Cycle 7 Calibration

17.4.1 Calibration Priorities

17.4.2 Calibration Status

17.5 Cycle 8 Calibration

17.6 Cycle 9 Calibration

17.7 Cycle 10 Calibration

17.8 Cycle 11 Calibration

17.9 Cycle 12 Calibration

17.10 SM4 and SMOV4 Calibration

17.11 Cycle 17 Calibration Plan

17.12 Cycle 18 Calibration Plan

Appendix A: Available-But-Unsupported
Spectroscopic Capabilities

A.1 Introduction

A.2 Full Aperture Complement

A.3 Central Wavelength Settings

Glossary

Index