Skip to Main Content

Trisha Ashley

Alumna Trisha Ashley at the Very Large Array.

Trisha Ashley stands at the Very Large Array in Socorro, New Mexico, where she took observations and attended a workshop on radio interferometry.

As a NASA Postdoctoral Program Fellow at the NASA Ames Research Center in California, Trisha Ashley is working with Dr. Pamela Marcum to study isolated galaxies that are suspected to have been formed by long-ago galaxy mergers. Dr. Ashley is also continuing to work on the project she was involved in as a graduate student at FIU, the LITTLE THINGS Survey (Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey). LITTLE THINGS aims to understand what regulates star formation in the most common type of galaxy, known as a dwarf galaxy. In massive spiral galaxies, star formation is generally provoked by gas clouds getting stuck in something like a traffic jam in their spiral arms. The gas clouds then begin bumping into each other, creating regions of high gas density from which stars can form. However, dwarf galaxies do not have spiral arms, so it isn’t known which processes are important for provoking their star formation. 

Dr. Ashley is particularly focused on understanding what triggers the bursts of star formation that are observed in a type of dwarf galaxy called blue compact dwarf (BCD) galaxies. She is now collecting new data and following up on her graduate research from FIU, where she discovered that BCDs are likely triggered by multiple external processes such as galaxy mergers, close interactions with galaxies around them, and consuming gas between galaxies. Her work on BCDs has shed light on a long-standing problem about how these galaxies suddenly experience high rates of star formation, which has implications for galaxy evolution, and thus how our universe has evolved over time.

Originally from upstate New York, Dr. Ashley received dual bachelor’s degrees in physics and astronomy at Bryn Mawr College in Pennsylvania. In 2014, she was awarded a Ph.D. in physics from FIU, where she worked with physics Professor Caroline Simpson on blue compact dwarf galaxies. Trisha loves having the opportunity her work allows to travel and see the world. She went to Baltimore to give a talk at the Space Telescope Science Institute, followed by a trip to Malta for a conference on gas in galaxies. Next, she traveled to Pune, India for a workshop on AstroSat, India’s first dedicated multi-wavelength space observatory, for which she was recently awarded observing time to take high-resolution ultraviolet (UV) images of four BCDs stemming from her dissertation work. These images will help to distinguish between different starburst triggers. For example, she does not expect to see young stars in the cold gas between galaxies, but she does expect to see young stars forming in gas that has been thrown out of a galaxy during a merger.  

When not researching BCDs, Trisha is the founder and organizer of the San Jose, California, chapter of the nationwide outreach group Astronomy on Tap. This program is a fun, public lecture series that takes place in a bar where local astronomers can have a beer with the public and give talks about astronomy.