HST Data Handbook for COS

Table of Contents

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Preface

Part I: Introduction to Reducing HST Data

Chapter 1: Obtaining HST Data

1.1 Archive Overview

1.1.1 Archive Processing

1.1.2 Archive Registration

1.1.3 Archive Documentation and Help

1.2 Obtaining Data via the MAST Web

1.2.1 MAST Overview

1.2.2 Hubble Legacy Archive

1.2.3 High-Level Science Products

1.3 Obtaining Data with StarView

Chapter 2: HST File Formats

2.1 HST Data Files

2.2 Multi-Extension FITS File Format

2.2.1 Working with Multi-Extension FITS Images in IRAF

2.2.2 Working with FITS Table Extensions

2.3 GEIS File Format

2.3.1 Converting Waiver FITS to GEIS

2.3.2 GEIS Data Groups

2.3.3 Working with GEIS Files

2.3.4 The waiver FITS Format

Chapter 3: Analyzing HST Data

3.1 Analysis Options for HST Data

3.1.1 IRAF/STSDAS

3.1.2 PyRAF

3.1.3 Python

3.1.4 Interactive Data Language (IDL)

3.1.5 Fortran and C

3.1.6 Java

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 FITS 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 COS and STIS Spectra

3.5.3 FOS and GHRS Spectra

3.5.4 Producing Hardcopy

3.6 Analyzing HST Spectra

3.6.1 Preparing COS and STIS Spectra for Analysis in IRAF or PyRAF and STSDAS

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: COS Data Handbook

Introduction

Chapter 1: COS Overview

1.1 Instrument Capabilities and Design

1.2 COS Physical Configuration

1.2.1 The COS Detectors

1.3 Basic Instrument Operations

1.3.1 Target Acquisitions

1.3.2 Routine Wavecals

1.3.3 Typical COS Observing Sequence

1.4 COS Coordinate System

Chapter 2: COS Data Files

2.1 Overview

2.2 COS File Names

2.3 COS File Structures

2.3.1 COS FITS Table Extension Files

2.3.2 COS FITS Image Extension Files

2.4 COS Data Products

2.4.1 Uncalibrated Science Data Files

2.4.2 Intermediate Science Data Files

2.4.3 Final Science Data Files (and Product Files)

2.4.4 Auxiliary Data Files

2.5 Data Storage Requirements

2.6 Headers, Keywords, and Relationship to Phase II

2.7 Error and Data Quality Array

2.7.1 Error Array

2.7.2 Data Quality Flags

Chapter 3: COS Calibration

3.1 Raw Data Compilation

3.2 Pipeline Processing Overview

3.3 Calcos: Structure and Data Flow

3.4 Descriptions of Spectroscopic Calibration Steps

3.4.1 Initialization

3.4.2 BRSTCORR: Search for and Flag Bursts

3.4.3 BADTCORR: Bad Time Intervals

3.4.4 PHACORR: Pulse Height Filter

3.4.5 RANDCORR: Add Pseudo-Random Numbers to Pixel Coordinates

3.4.6 TEMPCORR: Temperature-Dependent Distortion Correction

3.4.7 GEOCORR and IGEOCORR: Geometric Distortion Correction

3.4.8 DOPPCORR: Correct for Doppler Shift

3.4.9 DEADCORR: Nonlinearity Correction

3.4.10 FLATCORR: Flat Field Correction

3.4.11 WAVECORR: Wavecal Correction

3.4.12 DQICORR: Initialize Data Quality File

3.4.13 X1DCORR: Locate and Extract 1-D Spectrum

3.4.14 BACKCORR: 1D Spectral Background Subtraction

3.4.15 FLUXCORR/TDSCORR: Conversion to Flux

3.4.16 HELCORR: Correction to Heliocentric Reference Frame

3.4.17 STATFLAG: Report Simple Statistics

3.4.18 Finalization (making the sum files)

3.5 Descriptions of Imaging Calibration Steps

3.6 Customizing COS Data Calibration

3.6.1 Mechanics of Tailored Recalibration

3.6.2 Using GO Wavecals

3.7 Reference Files

3.7.1 BRSTTAB: Burst Parameters Table

3.7.2 BADTTAB: Bad Time Interval Table

3.7.3 PHATAB: Pulse Height Discrimination Table

3.7.4 BRFTAB: Baseline Reference Frame Table

3.7.5 GEOFILE: Geometric Correction File

3.7.6 DEADTAB: Deadtime Table

3.7.7 FLATFILE: Flat Field File

3.7.8 BPIXTAB: Bad Pixel Table

3.7.9 LAMPTAB: Template Calibration Lamp Spectra Table

3.7.10 WCPTAB: Wavecal Parameter Table

3.7.11 DISPTAB: Dispersion Coefficient Table

3.7.12 XTRACTAB: 1-D Spectral Extraction Table

3.7.13 PHOTTAB: Photometric Throughput Table

3.7.14 TDSTAB: Time Dependent Sensitivity Table

Chapter 4: COS Error Sources

4.1 Error Sources Associated with Pipeline Processing Steps

4.1.1 Dark Count

4.1.2 Flat Fields

4.1.3 FUV XDL Thermal Drifts

4.2 Factors Limiting Flux and Wavelength Accuracy

4.2.1 Flux Accuracy

4.2.2 Wavelength and Spectral Resolution Accuracies

Chapter 5: COS Data Analysis

5.1 Data Reduction and Analysis Applications

5.1.1 COS-Specific STSDAS Tasks

5.1.2 FITS Table Tasks

5.1.3 General Spectral Display and Analysis Tasks

5.2 Evaluating Target Acquisitions and Guiding

5.2.1 Types of Target Acquisitions

5.2.2 Guiding Errors for Single-Guide-Star Mode

5.3 Working with Extracted Spectra

5.3.1 Working With x1d Files in IDL

5.3.2 Working With x1d Files in IRAF/PyRAF

5.3.3 Redoing Spectral Extraction

5.3.4 Splicing Extracted Spectra

5.4 Working with TIME-TAG Data

5.4.1 Displaying TIME-TAG Data in DS9

5.4.2 Manipulating TIME-TAG Data for Variability

Part III: Appendixes

Appendix A: IRAF Primer

A.1 IRAF Overview

A.2 Initiating IRAF

A.2.1 Setting Up IRAF in Unix/Linux

A.2.2 Starting and Stopping an IRAF Session

A.3 IRAF Basics

A.3.1 Loading Packages

A.3.2 Running Tasks

A.3.3 Getting Help

A.3.4 Setting Parameters

A.3.5 Setting Environment Variables

A.3.6 File Management

A.3.7 Troubleshooting

A.4 PyRAF Capabilities

A.5 Accessing IRAF, PyRAF, and STSDAS Software

A.5.1 Accessing the Synphot Data Set

Appendix B: HST File Names

B.1 File Name Format

B.2 Rootnames

B.3 Suffixes of Files Common to All Instruments

B.3.1 Historical File Structures

B.4 Associations

Appendix C: Observation Logs

C.1 Observation Log Files

C.1.1 Jitter File Contents

C.1.2 Observation Log File Contents

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