Timothy Dolch

#1: Gravitational Wave Astrophysics

ripples in the fabric of spacetime

Pulsar Timing Arrays

First, I work with the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), an NSF Physics Frontiers Center dedicated to detecting gravitational waves (GWs) from merging supermassive black hole binaries. We observe many radio pulsars with Arecibo Obervatory and the Green Bank Telescope. These millisecond pulsars comprise a galaxy-sized GW telescope. We are part of the International Pulsar Timing Array (IPTA). Currently, I chair NANOGrav's Education and Public Outreach Working Group. (Image credits: Arecibo Observatory, Green Bank Observatory)

Cyclic Spectroscopy

Within NANOGrav's Noise Budget workiing group, I work on a signal processing technique called cyclic spectroscopy (https://arxiv.org/abs/2008.10562), which can be used to measure and mitigate the effects of the ionized interstellar medium on radio pulse propagation.

The J1713 24-hr Global Campaign

As a postdoc, I directed a nine-telescope, 24-hour continuous observation of the millisecond pulsar J1713+0747. The data release paper is here. Several spinoff projects resulted, such as a gravitational wave limit and single pulse studies. The data are still available to work on for anyone interested - please contact me if you are! All it takes is an associate membership in NANOGrav or in another IPTA collaboration.

#2: Bow-Shock Pulsar Wind Nebulae

Neutron stars with high velocities create beautiful "wake" structures in the interstellar medium. These structures are known as bow-shock pulsar wind nebuale (PWNe). When I was a postdoc at Cornell, we observed the Guitar Nebula (the PWN of pulsar B2224+65) with the Discovery Channel Telescope.

#3: Low-Frequency Radio Telescopes

The Low-Frequency All-Sky Monitor V is a radio telescope array on the Hillsdale College campus searching for bright radio transients. Students and I built the array with the generous support of the College's startup funds for new faculty. With our colleagues who run the other four stations around the North American continent, real astrophysical events will show up in multiple stations. Each station uses 13 LWA (Long-Wavelength Array) antennas sensitive to the 10-88 MHz bandwidth. We are working with our LWA colleagues to develop the planned LWA-Swarm radio telescope.

Research Topics