In The Astronomical Journal, Volume 150, 81 (2015).
http://arxiv.org/abs/1508.05153

For a PDF version of the article, click here.

CHANG-ES IV: RADIO CONTINUUM EMISSION OF 35 EDGE-ON GALAXIES OBSERVED WITH THE KARL G. JANSKY VERY LARGE ARRAY IN D-CONFIGURATION - DATA RELEASE 1

Theresa Wiegert 1, Judith Irwin 2, Arpad Miskolczi 3, Philip Schmidt 4, Silvia Carolina Mora 5, Ancor Damas-Segovia 6, Yelena Stein 7, Jayanne English 8, Richard J. Rand 9, Isaiah Santistevan 10, Rene Walterbos 11, Marita Krause 12, Rainer Beck 13, Ralf-Jurgen Dettmar 14, Amanda Kepley 15, Marek Wezgowiec 16, Q. Daniel Wang 17, George Heald 18, Jiangtao Li 19, Stephen MacGregor 20, Megan Johnson 21, A. W. Strong 22, Amanda DeSouza 23, Troy A. Porter 24


Abstract: We present the first part of the observations made for the Continuum Halos in Nearby Galaxies, an EVLA Survey (CHANG-ES) project. The aim of the CHANG-ES project is to study and characterize the nature of radio halos, their prevalence, as well as their magnetic fields and the cosmic rays illuminating these fields. This paper reports observations with the compact D-configuration of the Karl G. Jansky Very Large Array (VLA) for the sample of 35 nearby edge-on galaxies of CHANG-ES. With the new wide bandwidth capabilities of the VLA, an unprecedented sensitivity was achieved for all polarization products. The beam resolution is an average of 9.6" and 36" with noise levels reaching approximately 6 and 30 µJy/beam for C and L bands respectively (robust weighting).

We present intensity maps in these two frequency bands (C and L), with different weightings, as well as spectral index maps, polarization maps and new measurements of star formation rates. The data products described herein are available to the public in CHANG-ES Data Release available at http://www.queensu.ca/changes.

We also present evidence of a trend between galaxies with larger halos having higher SFR surface density, and show, for the first time, a radio continuum image of the median galaxy, taking advantage of the collective signal-to-noise of 30 of our galaxies. This image shows clearly that a ’typical’ spiral galaxy is surrounded by a halo of magnetic fields and cosmic rays.


Keywords : radio continuum: galaxies — galaxies: surveys, ...


Table of Contents

INTRODUCTION

OBSERVATION SETUP
Survey design
Observations

DATA REDUCTIONS
Calibrations
Flagging
Imaging
In-band Spectral Indices

RESULTS AND DATA PRODUCTS
Rms noise
Displaying the halo
Comments on individual galaxies

ANALYSIS
Flux densities
Star formation rates
Overview of the CHANG-ES sample ordered by SFR surface density

MEDIAN EDGE-ON GALAXY AND ITS HALO

CONCLUSIONS

APPENDIX A

REFERENCES




1 Dept. of Physics, Engineering physics & Astronomy, Queen’s University, Kingston, ON, Canada, K7L 3N6;
2 Dept. of Physics, Engineering Physics & Astronomy, Queen’s University, Kingston, ON, Canada, K7L 3N6
3 Astronomisches Institut, Ruhr-Universität Bochum, 44780 Bochum, Germany
4Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121, Bonn, Germany
5 Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121, Bonn, Germany
6 Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121, Bonn, Germany
7 Astronomisches Institut, Ruhr-Universität Bochum, 44780 Bochum, Germany
8 Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2
9 Dept. of Physics and Astronomy, University of New Mexico, 800 Yale Boulevard, NE, Albuquerque, NM, 87131, USA
10 Dept. of Physics and Astronomy, University of New Mexico, 800 Yale Boulevard, NE, Albuquerque, NM, 87131, USA
11 Dept. of Astronomy, New Mexico State University, PO Box 30001, MSC 4500, Las Cruces, NM 88003, USA
12 Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121, Bonn, Germany
13 Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121, Bonn, Germany
14 Astronomisches Institut, Ruhr-Universität Bochum, 44780 Bochum, Germany
15 NRAO Charlottesville, 520 Edgemont Road, Charlottesville, VA 22903-2475, USA
16 Astronomisches Institut, Ruhr-Universität Bochum, 44780 Bochum, Germany
17 Dept. of Astronomy, University of Massachusetts, 710 North Pleasant St., Amherst, MA, 01003, USA
18 Netherlands Institute for Radio Astronomy (ASTRON), Postbus 2, 7990 AA, Dwingeloo, The Netherlands
19 Dept. of Astronomy, University of Michigan, 311 West Hall, 1085 S. University Ave., Ann Arbor, MI 48109, USA
20 Dept. of Physics, Engineering physics & Astronomy, Queen’s University, Kingston, ON, Canada, K7L 3N6
21 CSIRO, PO Box 76, Epping, NSW 1710, Australia
22 Max-Planck-Institut für extraterrestrische Physik, Garching bei München, Germany
23 Dept. of Physics, Engineering physics & Astronomy, Queen’s University, Kingston, ON, Canada, K7L 3N6
24 Hansen Experimental Physics Laboratory, Stanford University, 452 Lomita Mall, Stanford, CA, 94305, USA

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