Harnessing the power of
multi-wavelength and
multi-messenger astrophysics
High-energy astrophysicist studying pulsars,
and using pulsars to search for gravitational waves.
As UMD research faculty resident at NASA Goddard, my work primarily focuses on supporting mission science productivity and educating the broader community to enable and elevate scientific returns. As a member of NASA's Neutron Star Interior Composition Explorer (NICER) mission on the International Space Station, I serve as the Lead Scientist for the General Observer Facility, which provides access to the instrument for members of the global scientific community.
Over the past 25 years, I have worked on the lauches for three major NASA missions (Aqua, Aura, and Fermi), and contributed significantly to the development of major Fermi source catalogs, both for point sources and for pulsars that are detected in the gamma-ray band. I am currently involved in the Laser Interferometry Space Antenna (LISA) mission being developed as a partnership bewteen the European Space Agency and NASA for a planned launch in 2035. I also serve as the current Treasurer for the High Energy Astrophysics Division of the American Astronomical Society.
More information on these topics can be found below:
The Fermi Gamma-ray Space Telescope (Fermi) seems to detect many millisecond pulsars (MSPs), neutron stars that formed in binary systems with rotation rates that are sped up due to mass transfer from their companion star. Most of these detections have not been seen in other wavebands. This makes new gamma-ray sources a treasure map (h/t Paul Ray) for scientists seeking new pulsars.
As a member of Fermi’s Pulsar Search Consortium (PSC), I search for pulsar-like gamma-ray sources to search for radio pulsations from neutron stars. Gamma-ray brightness does not predict radio brightness, meaning that even very faint Fermi sources could be undiscovered pulsars. I frequently generate lists of sources that are likely to be pulsars, which I provide to members of the PSC for targeted radio searches. For a variety of reasons, these new discoveries tend to be millisecond pulsars.
In addition, millisecond pulsars are used to study extremely dense matter by using X-ray observations to measure relativistic light-bending effects near the surface of the neutron star. This research is impossible to perform on Earth and has profound implications for how dense matter behaves under extreme pressure. I maintain a listing of the known rotation-powered pulsars in the Milky Way Galaxy, and a similar reference list for accreting millisecond X-ray pulsars. Both lists are accessible below in the Reference Lists section.
The North American Nanohertz Observatory fro Gravitational Waves (NANOGrav) is a collaboration of pulsar and gravitational wave researchers dedicated to the long-term timing of millisecond pulsars for the purpose of detecting low-frequency gravitational waves using a galactic-scale detector called a Pulsar Timing Array (PTA). Adding more pulsars to the PTA is one of the best ways to increase its sensitivity to gravitational waves. As a member of this scientific collaboration, I focus my efforts on surveying new pulsar discoveries for pulsars with the appropriate characteristics to contribute to the PTA.
As a result of these efforts, the number of pulsars being monitored by NANOGRav increased by almost 50% between 2013 and 2018, allowing for the detection of evidence for low-frequency gravitational waves in the 15-year data set. These results were announced by the NSF in June 2023.
In addition, I serve as the Press Officer for NANOGrav. As part of the National Science Foundation's (NSF) announcement of the 15-year science results, I created a comprehensive press kit, developed most of the announcement animations, and compiled the presentation use during the public annoucement. Links are provided below.
NANOGrav and LIGO (the Laser Interferometer Gravitational-wave Observatory) provide visibility into the Universe at opposite ends of the gravitational wave spectrum. NANOGrav science targets waves generated by binary black homes with masses of millions of times the mass of the Sun, while ground-based LIGO detections are of merger of black holes with only ten to one hundred times the mass of the Sun. Neither observatory can detect inspirals and mergers of either intermediate mass black holes (thousands of times the mass of the Sun) or of megers wwhere the two black hole masses are significantly different, called Extreme Mass-Ratio Inspirals (EMRIs).
LISA, the Laser Interferometer Space Antenna is a joint mission between the European Space Agency (ESA) and NASA that will target this gap, targeted to launch in 2035. In order to be sensitive to these masses, LISA consists of a contellation of three spacecraft connected by lasers that for a triangle large enough to contain the Sun.
UMD astronomer Elizabeth Ferrara was part of a 15-year collaboration that used radio telescopes to tune into the hum of the cosmos.
Pulsars point the way on gravitational waves, via black holes on an almost unfathomable scale. Astrophysicist Elizabeth Ferrara was one of nearly 200 scientists who have been gathering data on pulsars for 15 years.
Please email for more information about my research, or to ask that I speak at your conference, event, or podcast.
As the Press Officer for NANOGrav, I write press releases for the group and handle press requests. If you are interested in NANOGrav, you can find more about the group at our website. If you'd like to request a speaker discussing the detection of gravitational waves using pulsars, you can submit your request to press@nanograv.org.
Below are some press releases I have written for NANOGrav:
NANOGrav's announcement of the first evidence for a stochastic background of gravitational waves seen in 15 years of pulsar timing data.
In data gathered and analyzed over 13 years, NANOGrav announced an intriguing low-frequency signal that may be attributable to gravitational waves.
NANOGrav's 11-year data set establishes astrophysically significant limits in the search for low-frequency gravitational waves.
In regonition of contributions to the successful global annoucement of NANOGrav's 15-year data release and the announcement of the first evidence for a low-frequency stochastic background of gravitational waves.
As different classes of millisecond pulsars are discovered, it has become helpful to have a single repository containing up-to-date information of the various members of each class.
If using these lists in research, please link to the URL containing the list and give credit to these pages.
Many thanks,
Elizabeth
I have numerous interests outside of work. Here's a list of most of them, though I reserve the right to find new hobbies at the drop of a hat.