Data Combination: Interferometry and Single-dish Imaging in Radio Astronomy

Publications of the Astronomical Society of the Pacific, vol. 135, pp. 034501

Abstract

Abstract Modern interferometers routinely provide radio-astronomical images down to subarcsecond resolution. However, interferometers filter out spatial scales larger than those sampled by the shortest baselines, which affects the measurement of both spatial and spectral features. Complementary single-dish data are vital for recovering the true flux distribution of spatially resolved astronomical sources with such extended emission. In this work, we provide an overview of the prominent available methods to combine single-dish and interferometric observations. We test each of these methods in the framework of the CASA data analysis software package on both synthetic continuum and observed spectral data sets. We develop a set of new assessment tools that are generally applicable to all radio-astronomical cases of data combination. Applying these new assessment diagnostics, we evaluate the methods’ performance and demonstrate the significant improvement of the combined results in comparison to purely interferometric reductions. We provide combination and assessment scripts as add-on material. Our results highlight the advantage of using data combination to ensure high-quality science images of spatially resolved objects.

Authors 14

1. Adele Plunkett

   National Radio Astronomy Observatory

   Affiliation as printed

   National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA; aplunket@nrao.edu

   National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA

2. A. Hacar Aachen Leiden Observatory

   Leiden University · University of Vienna · Leiden Observatory

   Affiliation as printed

   Department of Astrophysics, University of Vienna, Türkenschanzstrasse 17, 1180, Vienna, Austria

   Leiden Observatory, Leiden University, PO Box 9513, 2300-RA Leiden, The Netherlands

3. Lydia Moser-Fischer
   Affiliation as printed

   Argelander-Institut fuer Astronomie, Auf dem Huegel 71, D-53121 Bonn, Germany

4. D. Petry

   European Southern Observatory

   Affiliation as printed

   European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany

5. Peter J. Teuben

   University of Maryland, College Park

   Affiliation as printed

   Astronomy Department, University of Maryland, 4296 Stadium Drive, College Park, MD 20742, USA

6. Nickolas M. Pingel

   Australian National University · University of Wisconsin–Madison

   Affiliation as printed

   Department of Astronomy, University of Wisconsin–Madison, 475 North Charter Street, Madison, WI 53706, USA

   Research School of Astronomy and Astrophysics, The Australian National University, Canberra, ACT 2611, Australia

7. D. Kunneriath

   National Radio Astronomy Observatory

   Affiliation as printed

   National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA; aplunket@nrao.edu

   National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA

8. Toshinobu Takagi

   Japan Space Forum

   Affiliation as printed

   Japan Space Forum, 3-2-1 Kandasurugadai, Chiyoda-ku, Tokyo 101-0062, Japan

9. Yusuke Miyamoto

   Fukui University of Technology · National Astronomical Observatory of Japan

   Affiliation as printed

   Department of Electrical and Electronic Engineering, Fukui University of Technology, 3-6-1, Gakuen, Fukui, 910-8505, Japan

   National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan

10. Emily Moravec
    Affiliation as printed

    Green Bank Observatory, PO Box 2, Green Bank, WV 24944, USA

11. S. Suri

    University of Vienna

    Affiliation as printed

    Department of Astrophysics, University of Vienna, Türkenschanzstrasse 17, 1180, Vienna, Austria

12. Kelley M. Hess

    Instituto de Astrofísica de Andalucía · Netherlands Institute for Radio Astronomy

    Affiliation as printed

    ASTRON, The Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo, The Netherlands

    Instituto de Astrofísica de Andalucía (CSIC), Glorieta de la Astronomía s/n, E-18008 Granada, Spain

13. Melissa Hoffman

    Space Telescope Science Institute

    Affiliation as printed

    Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA

14. Brian Mason

    National Radio Astronomy Observatory

    Affiliation as printed

    National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA; aplunket@nrao.edu

    National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA