Explanatory Supplement to the 2MASS Second Incremental Data Release

Cutri, R.M. (IPAC/Caltech), Skrutskie, M.F. (UMASS), Van Dyk, S., Chester, T., Evans, T., Fowler, J., Gizis, J. (IPAC/Caltech), Howard, E. (UMASS), Huchra, J. (Harvard-Smithsonian CfA), Jarrett, T., Kopan, E.L., Kirkpatrick, J.D., Light, R.M, Marsh, K.A., McCallon, H. (IPAC/Caltech), Schneider, S., Stiening, R. (UMASS), Sykes, M. (U.Arizona), Weinberg, M. (UMASS), Wheaton, W.A., Wheelock, S. (IPAC/Caltech)

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Table of Contents

I. Introduction

1. 2MASS Overview
2. The 2MASS Sky
3. Executive Summary of 2MASS Second Incremental Data Products
   1. Point Source Catalog
   2. Extended Source Catalog
   3. Image Products
4. Distribution Mode for 2MASS Products
5. Data Release Plan
6. Cautionary Notes
   1. General
   2. Point Source Catalog (PSC)
   3. Extended Source Catalog (XSC)
   4. Atlas Images
7. Acknowledgments
   1. 2MASS Personnel
8. Referencing 2MASS
   1. 2MASS Source Naming Convention
   2. Acknowledging 2MASS in Publications

II. Contents of the 2MASS Second Incremental Data Release

1. General Properties of the Data Release
2. Point Source Catalog
   1. Format
   2. Selection Criteria
   3. General Properties
   4. Photometric Properties
   5. Astrometric Properties
   6. Miscellaneous
3. Extended Source Catalog
   1. Format
   2. Selection Criteria
   3. General Properties
   4. Photometric Properties
   5. Size Distribution
   6. Relevant Images
4. Atlas Images
5. Extended Source Postage Stamp Images
6. Ancillary Files
   1. Point Source Record Format
   2. Extended Source Record Format
   3. Atlas Image Header Description
   4. Scan Information Table
   5. Known Asteroid Detection List
   6. Known Comet Detection List
   7. Known Planet and Satellite Detection List
   8. PSC and XSC Anomaly Files

III. 2MASS Facilities and Operations

1. Facilities
   1. Telescopes
   2. Camera and Detectors
   3. Observatory Sites and Site Conditions
2. Data Acquisition
   1. Scanning Strategy
   2. Survey Strategy
   3. Photometric Calibration Strategy

IV. 2MASS Data Processing

1. Processing Pipeline Overview
2. Instrumental Frame Correction
3. Atlas Image Generation
   1. Image Estimation Using Kernel Smoothing
4. Point Source Detection and Photometry
   1. Band Merging and Bandfills
   2. Optical Source Associations
5. Extended Source Identification and Photometry
6. Position Reconstruction
7. Artifact Identification
8. Photometric Calibration
9. Known Asteroid, Comet, Planet, and Satellite Associations
10. Quality Assurance

V. Catalog Generation

1. Overview
2. Tile Selection
   1. Date Range
   2. Photometric Quality
   3. Average Seeing
   4. Residual Background Structure
   5. Multiple Tile Observations
   6. Tile Contiguity
   7. Other area considerations
3. Source Selection
4. Tile Edges and Overlap Resolution
   1. Tile Edges
   2. Overlap Resolution
   3. Unbounded Tile Edges
5. Bright Star and Galaxy Placeholders

VI. Analysis of Release Catalogs

1. Comparison of Achieved Performance of Second Incremental Release Catalogs with Level 1 Science Specification
2. Global Photometric Properties
3. Completeness and Reliability
4. PSC Characteristics in Selected Reference Regions
5. Comparison to External Catalogs and Models

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Last modified 2000 Feb 16. For assistance, contact 2mass@ipac.caltech.edu