Table of Contents

Table of Contents

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Preface

Part I: Introduction to Reducing the HST

Chapter 1: Getting HST Data

1.1 Archive Overview

1.1.1 Archive Registration

1.1.2 Archive Documentation and Help

1.2 Getting Data with StarView

1.2.1 Downloading and Setting Up StarView

1.2.2 Simple Use of StarView

1.2.3 Marking and Retrieving Data with StarView

1.2.4 Using StarView to Retrieve Calibration Files and Proposal Information and for Duplication Checking

1.2.5 Advanced Features of StarView

1.2.6 StarView and the Visual Target Tuner

1.2.7 Quick Proprietary Data Retrieval with StarView

1.3 Getting Data with the World Wide Web

1.3.1 WFPC2 Associations

1.3.2 High Level Science Products

1.4 Reading HST Data Disks

Chapter 2: HST File Formats

2.1 FITS File Format

2.1.1 Working with FITS Image Extensions

2.1.2 Working with FITS Table Extensions

2.2 GEIS File Format

2.2.1 Converting FITS to GEIS

2.2.2 GEIS Data Groups

2.2.3 Working with GEIS Files

2.2.4 The "waiver" FITS Format

Chapter 3: Analyzing HST Data

3.1 Alternative Means of Accessing HST Data

3.1.1 Interactive Data Language (IDL)

3.1.2 Python

3.1.3 Fortran and C

3.1.4 Java

3.1.5 PyRAF

3.2 Navigating STSDAS

3.2.1 STSDAS Structure

3.2.2 Packages of General Interest

3.3 Displaying HST Images

3.3.1 The Display Task

3.3.2 Working with Image Sections

3.4 Analyzing HST Images

3.4.1 Basic Astrometry

3.4.2 Examining and Manipulating Image Data

3.4.3 Working with STIS, ACS, and NICMOS Imsets

3.4.4 Photometry

3.4.5 Combining Dithered HST Datasets with MultiDrizzle

3.5 Displaying HST Spectra

3.5.1 Specview

3.5.2 STIS Spectra

3.5.3 FOS and GHRS Spectra

3.5.4 Producing Hardcopy

3.6 Analyzing HST Spectra

3.6.1 Preparing STIS Spectra for Analysis in IRAF/STSDAS or Pyraf

3.6.2 Preparing FOS and GHRS Data

3.6.3 Photometry

3.6.4 General Tasks for Spectra

3.6.5 STSDAS Fitting Package

3.6.6 Specfit

3.7 References

3.7.1 Available from STScI

3.7.2 Available from NOAO

3.7.3 Other References Cited in This Chapter

Part II: NICMOS Data

NICMOS Introduction

How to Use this Handbook

Chapter 1: Instrument Overview

1.1 Instrument Overview

1.2 Detector Readout Modes

1.2.1 MULTIACCUM

1.2.2 ACCUM

1.2.3 BRIGHTOBJ

1.2.4 RAMP

Chapter 2: Data Structures

2.1 NICMOS Data Files

2.1.1 File Name Suffixes

2.1.2 Science Data Files

2.1.3 Auxiliary Data Files

2.2 Header Keywords

2.3 Working with NICMOS Files

2.4 From the Phase II Proposal to Your Data

2.5 Paper Products

Chapter 3: Calibration

3.1 Pipeline Processing, OTFR, and the HST Archive

3.2 NICMOS Calibration Software

3.2.1 The Calibration Pipeline

3.2.2 Software for Grism Data Reduction

3.3 Basic Data Reduction: calnica

3.4 Mosaicing: calnicb

3.4.1 Input Files

3.4.2 Output Files

3.4.3 Processing

3.5 Recalibration

3.5.1 Why Recalibrate?

3.5.2 Recalibrating the Data

3.6 Calibration Goals and Plans

3.6.1 Calibration Accuracies

3.6.2 Monitoring Programs

3.6.3 Special Programs

3.6.4 Calibration in Previous Cycles

3.6.5 Special Calibrations

Chapter 4: Anomalies and Error Sources

4.1 NICMOS Dark Current and Bias

4.1.1 Dark Current

4.1.2 Bias, Shading, and "Pedestal"

4.1.3 Dark Reference Files

4.1.4 Cures: How To Get Rid of What's Left

4.2 Bars

4.3 Detector Nonlinearity Issues

4.3.1 New Nonlinearity Calibrations

4.3.2 Non-Zero zeroth Read Correction for Bright Sources

4.3.3 Uncorrected Saturation

4.4 Flatfielding

4.4.1 Characteristics of NICMOS Flatfields

4.4.2 Temperature-dependent Flatfields

4.4.3 Color Dependence of Flatfields

4.5 Count Rate Non-Linearity

4.6 Pixel Defects and Bad Imaging Regions

4.6.1 Hot Pixels, Cold Pixels, and Grot

4.6.2 Erratic Middle Column/Row.

4.6.3 Coronagraphic Hole

4.6.4 Vignetting

4.7 Effects of Overexposure

4.7.1 Photon Persistence

4.7.2 Cosmic Ray Persistence

4.7.3 Amplifier Ringing (The "Mr. Staypuft" Anomaly)

4.7.4 Optical Ghost Images

4.8 Cosmic Rays of Unusual Size

4.9 Scattered Earthlight

Chapter 5: Data Analysis

5.1 STSDAS Software

5.2 The NICMOS History Tool

5.3 Photometric Calibrations

5.3.1 Units for NICMOS Photometry

5.3.2 Fluxes and Magnitude Zeropoints

5.3.3 Photometric Corrections

5.3.4 Absolute Photometry for Emission Line Filters

5.3.5 Absolute Spectrophotometry with NICMOS Grisms

5.4 Astrometry, Pixel scales, and Geometric Distortion

5.4.1 Pixel Scales

5.4.2 Geometric Distortion

5.4.3 Drizzling

5.4.4 Absolute Astrometry

5.5 PSF Subtraction

5.5.1 Impact of Instrumental Effects on PSF Subtraction

5.6 Coronagraphic Reductions

5.6.1 Data Products and File Structures

5.6.2 Coronagraphic Acquisitions

5.6.3 Positions of the Hole and Target

5.6.4 Recalibrating Coronagraphic Images

5.6.5 Reducing and Co-adding Coronagraphic Images

5.7 Analysis of Polarization Images

5.7.1 Introduction

5.7.2 Theory

5.7.3 A Useful Script for Polarization Analysis

5.8 Grism Data Reduction

5.8.1 Extraction Software

5.8.2 Processing

Part III:

Appendix A: IRAF Primer

A.1 Initiating IRAF

A.1.1 Setting Up IRAF in Unix/Linux

A.1.2 Starting and Stopping an IRAF Session

A.2 IRAF Basics

A.2.1 Loading Packages

A.2.2 Running Tasks

A.2.3 Getting Help

A.2.4 Setting Parameters

A.2.5 Setting Environment Variables

A.2.6 File Management

A.2.7 Troubleshooting

A.3 Getting IRAF and STSDAS

A.3.1 Retrieving the IRAF and STSDAS Software

A.3.2 Getting the Synphot Database

A.3.3 Extracting the Synphot Unix Tar Files

Appendix B: HST File Names

B.1 Rootnames

B.2 Suffixes of Files Common to All Instruments

B.3 Associations

Appendix C: Observation Logs

C.1 Observation Log Files

C.1.1 Observation Log File Contents (October 1994 version)

C.1.2 Observation Log File Contents (August 1995 version)

C.1.3 Observation Log File Contents (February 1997 version)

C.1.4 Jitter File Contents (February 2003 Version)

C.2 Retrieving Observation Logs

C.3 Using Observation Logs

C.3.1 Guiding Mode

C.3.2 Guide Star Acquisition Failure

C.3.3 Moving Targets and Spatial Scans

C.3.4 High Jitter

Index