Galaxies & Galaxy Interactions

I spend much of my research time looking at the hydrogen gas in polar-ring galaxies. PRG's are otherwise ordinary (albeit small) galaxies with a large ring of gas, dust, & stars that rotates perpendicular to the central galaxy. When the polar ring is seen edge-on, as in NGC 5122 (see image at right), PRG's have a characteristic "X" shape on the sky. Because the ring material is perpendicular to the central galaxy, and because the rings tend to have much more neutral gas than is common for the type of galaxy at the center, it is thought that polar rings formed from a merger or accretion event between two galaxies in the recent past. Currently, however, very little is known about exactly how polar rings form.

In addition to polar rings, I am interested in gas in galaxies and galaxy interactions in a more general sense. I am investigating the gas in "superthin" galaxies with Lynn Matthews, of the Harvard-Smithsonian Center for Astrophysics. I am also looking at radio-continuum emission from star formation regions in the nuclei of galaxies with Alan Watson at The Institute of Astronomy at Morelia.

Planet Search

I have recently begun a "planet search", with collaborator Stacy Palen of Weber State University (in Utah; pronounced "Wee-bur", not "Web-ur"). The "MaCHO" Project database is a treasure-trove of information about nearby stars. It was originally intended as a way to search for dark-matter candidates called "MaCHO's" (from "Massive Compact Halo Objects). However, we are using the data (now in the public domain, and freely available to all) to search for new planets! If you are a Beloit student, and want to become involved in this project, please contact me. You don't need to be a physics major -- you just need to be interested, and willing to spend a few hours a week working at a computer. At least one course in physics or astronomy, plus comfort with mathematics, is strongly recommended, though, or you'll need to spend a lot of prep-time before starting the real "data-crunching".

Papers in Progress

• "Neutral Hydrogen in the Polar-Ring Galaxy UGC 9796",
  to be submitted to the Astronomical Journal, October 2004
• "Using Writing to Learn in Introductory Astronomy",
  to be submitted to the Astronomy Education Review, Fall/Spring 2004/05
• "Gas Kinematics of the Polar Ring in NGC 5122",
  to be submitted to the Astronomical Journal, Spring/Summer 2005

Refereed Papers

• "Radio Continuum Emission in Polar-Ring Galaxies"
  Cox & Sparke 2004, AJ, accepted for publication in Nov 2004 issue
• "Stars and Gas in the Galaxy Pair II Zw 70/71"
  Cox, Sparke, Watson, & van Moorsel 2001, AJ, 121, 692
• "Optical and 21cm Observations of the Warped, Edge-on Galaxy UGC 7170"
  Cox, Sparke, van Moorsel, & Shaw 1996, AJ, 111, 1505

Conference Proceedings

• "New Observations of Polar Ring Galaxies"
  Sparke & Cox 2000, PASP Conference Series, 197, 119
• "Using Neutral Hydrogen to Probe Galaxy Potentials"
  Cox & Sparke 1996, PASP Conference Series, 106, 168
• "Observations of Warped Disks & Polar Rings in the 21cm Line of Neutral Hydrogen"
  Cox, Sparke, Richter, & Shaw 1995, in "Three-Dimensional Systems", Annals of the NYAS, 751, 27

Other Publications

• "Radio Observations of Nuclear Starbursts in NGC 2903, IC 342, & NGC 6946"
  Cox, Watson, & Wilcots 1997, BAAS, 190, #40.03
  (190th meeting of the AAS - Winston-Salem, NC, June 1997)
• "Neutral Hydrogen & Radio Continuum Emission in Polar-Ring Galaxies"
  Cox 1996, Ph.D. thesis, University of Wisconsin - Madison
• "Neutral Hydrogen in the II Zw 70/71 System: The Formation of a Polar Ring?"
  Cox, Sparke, Brinks, & van Moorsel 1996, BAAS, 188, #06.11
  (188th meeting of the AAS - Madison, WI, June 1996)
• "New HI Observations of the Galaxy Pair II Zw 70 / II Zw 71"
  Cox, A.L., Brinks, E., & Sparke, L.S., for the November 1995 New Mexico Symposium
• "A Step-by-Step Guide to Spectral-Line Data Reduction in AIPS"
  Cox 1995, Appendix B of the NRAO AIPS Cookbook
• "A VLA Radio Continuum Survey of Polar-Ring Galaxies"
  Cox & Sparke 1994, BAAS, 26, 1399
  (185th meeting of the AAS - Tuscon, AZ, January 1995)
• "Observations of Polar-Ring Galaxies in the 21cm Line of Neutral Hydrogen"
  Cox & Sparke 1994, BAAS, 26, 911
  (184th meeting of the AAS - Minneapolis, MN, June 1994)