Table of Contents 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 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 STIS Spectra 3.5.2 FOS and GHRS Spectra 3.5.3 Producing Hardcopy 3.6 Analyzing HST Spectra 3.6.1 Preparing STIS Spectra for Analysis 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: ACS Data ACS Introduction How to Use this Handbook Chapter 1: ACS Overview 1.1 Instrument Design and Capabilities 1.1.1 Detectors 1.1.2 ACS Optical Design 1.1.3 ACS Geometric Distortion 1.2 Basic Instrument Operations 1.2.1 Target Acquisitions 1.2.2 Typical ACS Observing Sequence 1.2.3 Data Storage and Transfer 1.2.4 Parallel Operations Chapter 2: ACS Data Structure 2.1 Types of ACS Files 2.1.1 Data Files and Suffixes 2.1.2 Association Tables 2.1.3 Trailer Files 2.2 ACS File Structure 2.3 Data Storage Requirements 2.4 Headers and Keywords Chapter 3: ACS Calibration Pipeline 3.1 On The Fly Reprocessing (OTFR) 3.2 Pipeline Overview 3.2.1 CALACS: Image Calibration 3.2.2 MultiDrizzle and PyDrizzle: Distortion 3.2.3 When is OTFR not Appropriate? 3.3 Structure of CALACS 3.4 CALACS Processing Steps 3.4.1 ACSCCD 3.4.2 ACSREJ 3.4.3 ACS2D 3.4.4 ACSSUM 3.5 Manual Recalibration of ACS Data 3.5.1 Requirements for Manual Recalibration 3.5.2 CALACS Examples Chapter 4: Distortion Correction and Drizzling of ACS Images 4.1 ACS Geometric Distortions 4.1.1 Distortion Model 4.1.2 On-orbit Calibration Programs 4.1.3 Results 4.1.4 Distortion Reference Files (IDCTAB & DGEOFILE) 4.2 Combination of Dithered Data 4.2.1 Introduction to Dithering 4.2.2 Introduction to Drizzle 4.2.3 Overview of Drizzle-Related Software Tools 4.2.4 Association Table Usage 4.3 PyDrizzle 4.4 MultiDrizzle 4.4.1 Steps Performed by MultiDrizzle 4.4.2 Multidrizzle in the ACS Pipeline 4.4.3 Data Quality Flags for Bad Pixels: The 'Bits' Parameter 4.4.4 MultiDrizzle Data Products 4.5 Post-Pipeline Reprocessing 4.5.1 Example 1: Running PyDrizzle on a Single Exposure 4.5.2 Example 2: Running PyDrizzle on an Association file 4.5.3 Example 3: Re-Running MultiDrizzle with Different Output Image Options 4.5.4 Example 4: Re-Running MultiDrizzle to Improve Sky Subtraction 4.6 Refining the Shift Determination 4.6.1 Delta Shifts 4.6.2 Absolute Shifts 4.6.3 Constructing the 'shiftfile' 4.6.4 Example 5: Improving the Image Registration for Different Visits 4.7 MultiDrizzle Details: Example Application to the Tadpole Galaxy 4.8 Creating Custom Association Tables Chapter 5: ACS Error Sources 5.1 Readout Noise and A-to-D Conversion 5.1.1 Readout Noise 5.1.2 A-to-D Conversion 5.2 Bias Subtraction 5.2.1 Bias Calibration Issues 5.2.2 Bias Jump 5.2.3 Bias Subarrays for the WFC and HRC 5.3 Dark Current, Hot Pixels, and Cosmic Rays 5.3.1 Dark Current 5.3.2 Hot Pixels 5.3.3 Cosmic Rays 5.4 Flat Fields 5.4.1 Ground Flats (P-flats) 5.4.2 Inflight L-flat Correction 5.4.3 Pipeline Flats 5.4.4 Earth Flat Verification 5.4.5 Sky Flats 5.5 Image Anomalies 5.5.1 Dust Motes 5.5.2 Optical Ghosts and Scattered Light 5.5.3 Cross Talk 5.5.4 Scattered Earth Light 5.6 Generic Detector and Camera Properties 5.6.1 Gain Calibration 5.6.2 Full Well Depth 5.6.3 Linearity at Low to Moderate Intensity 5.6.4 Linearity Beyond Saturation 5.6.5 Shutter Stability Chapter 6: ACS Data Analysis 6.1 Photometry 6.1.1 Photometric Systems, Units, and Zeropoints 6.1.2 Aperture and Color Corrections 6.1.3 Pixel Area Maps 6.1.4 PSF 6.1.5 CTE 6.1.6 Red Leak 6.1.7 UV Contamination 6.2 Astrometry 6.2.1 Coordinate Transformations 6.2.2 Absolute and Relative Astrometry 6.2.3 Impact of Guide Star Failure 6.3 Polarimetry 6.3.1 Absolute Calibration 6.3.2 Instrumental Issues 6.3.3 Flats 6.3.4 Polarization Calibration 6.4 Coronagraphy 6.4.1 Flat Fielding 6.4.2 PSF Subtraction 6.4.3 Photometry 6.4.4 Ghosting 6.5 Ramp Filters 6.5.1 Introduction 6.5.2 Existing Ground Calibrations 6.5.3 Future In-flight Calibrations 6.6 Spectroscopy with the ACS Grisms and Prisms 6.6.1 What to Expect from ACS Slitless Spectroscopy Data 6.6.2 Pipeline Calibration 6.6.3 Slitless Spectroscopy Data and Dithering 6.6.4 Extracting and Calibrating Slitless Spectra 6.6.5 Accuracy of Slitless Spectra Wavelength and Flux Calibration 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 (February 1997 version) C.1.3 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
