Finding Relativistic Stellar Explosions as Fast Optical Transients

Event Date:
2025-01-06T16:00:00
2025-01-06T17:00:00
Event Location:
HENN 318
Speaker:
Anna Ho, Cornell University
Related Upcoming Events:
Astronomy Colloquia
Intended Audience:
Everyone
Local Contact:

Allison Man (Aman@phas.ubc.ca) and Brett Gladman (gladman@astro.ubc.ca)

All are welcome to this in-person event!

Event Information:

Abstract:

For the last half-century, relativistic outflows accompanying the final collapse of massive stars have predominantly been detected via high-energy emission, as long-duration gamma-ray bursts (GRBs). Yet, it has long been hypothesized that GRBs are the tip of the iceberg of relativistic stellar explosions, because the conditions required to produce and detect a GRB are contrived. I will present results from a search for relativistic stellar explosions using optical time-domain surveys. The emerging zoo includes afterglows at cosmological distances with no detected GRB, supernovae with luminous X-ray and radio emission, and a mysterious class of "fast blue optical transients" with minute-timescale optical flares at supernova-like luminosities. An understanding of the origin of these events and their relation to GRBs will be enabled by upcoming time-domain surveys in other bands, including X-ray, UV, and submillimeter.

Bio:

Anna Ho's research uses telescopes located all over the world and in space to study the lives and deaths of stars and the physics of those phenomena and other energetic cosmic events.  She uses wide-field surveys along with targeted observations from gamma-ray to radio wavelengths, and works to understand the physical processes governing the observed emission. She is an active member of several international collaborations, and serves as co-chair of the gamma-ray bursts working group for the ULTRASAT mission.

Learn More:

Add to Calendar 2025-01-06T16:00:00 2025-01-06T17:00:00 Finding Relativistic Stellar Explosions as Fast Optical Transients Event Information: Abstract: For the last half-century, relativistic outflows accompanying the final collapse of massive stars have predominantly been detected via high-energy emission, as long-duration gamma-ray bursts (GRBs). Yet, it has long been hypothesized that GRBs are the tip of the iceberg of relativistic stellar explosions, because the conditions required to produce and detect a GRB are contrived. I will present results from a search for relativistic stellar explosions using optical time-domain surveys. The emerging zoo includes afterglows at cosmological distances with no detected GRB, supernovae with luminous X-ray and radio emission, and a mysterious class of "fast blue optical transients" with minute-timescale optical flares at supernova-like luminosities. An understanding of the origin of these events and their relation to GRBs will be enabled by upcoming time-domain surveys in other bands, including X-ray, UV, and submillimeter. Bio: Anna Ho's research uses telescopes located all over the world and in space to study the lives and deaths of stars and the physics of those phenomena and other energetic cosmic events.  She uses wide-field surveys along with targeted observations from gamma-ray to radio wavelengths, and works to understand the physical processes governing the observed emission. She is an active member of several international collaborations, and serves as co-chair of the gamma-ray bursts working group for the ULTRASAT mission. Learn More: See Anna's faculty webpage from Cornell University, here: https://astro.cornell.edu/anna-yq-ho  Find her personal website here: https://annayqho.github.io/  What are long-duration gamma-ray bursts (GRBs): Imagine the Universe!  What are fast blue optical transients: Dying stars’ cocoons might explain fast blue optical transients - Northwestern Now What is the ULTRASAT mission: Ultraviolet Transient Astronomy Satellite (ULTRASAT)  Event Location: HENN 318