Curtis V. McCully

Postdoctoral Fellow

Las Cumbres Observatory Global Telescope Network

University of California Santa Barbara


Mailing Address:
Curtis McCully
6740 Cortona Dr.,
Suite 102
Goleta, CA 93117



The extreme type Iax SN 2008ha in UGC 12682. Image Credit: Stefan Taubenberger/MPA

A type Ia supernova marks the explosive death of a white dwarf star. These explosions are all (approximately) the same brightness, so we can use their observed brightness to calculate the distance to galaxies, which we can then use to measure the expansion of the universe. The use of type Ia supernovae as distance indicators led to the discovery that the universe is not only expanding, but that the expansion is accelerating. The driver of this acceleration, called "Dark Energy", is still largely a mystery. This discovery was recognized with the Nobel Prize in Physics in 2011. Despite this success, we have discovered that not all white-dwarf supernovae produce normal type Ia supernovae. I study a subclass of peculiar white-dwarf supernovae which we have dubbed type Iax supernovae. By studying the differences between the peculiar supernovae and heir normal cousins, we hope to better understand the physics behind white-dwarf supernovae which we can use to better calibrate our cosmic distance indicators.

A gravitationally lensed galaxy forming nearly a complete Einstein ring. Image credit: APOD/NASA/HST

Gravitational Lensing is the bending of star light due to gravity. Mass, like a galaxy, between us and a distant background source can act as a lens, magnifying and distorting the image of the background source that we actually observe. This effect is not unlike looking at a candle through the base of a wine glass. The shapes and brightnesses of e distorted images can be used to study mass in the lens. As Lensing is only due to gravity, it is sensitive to all matter whether or not it emits light that we can see. This makes it a uniquely effective probe of matter we can't see, like dark matter that makes up 80% of the matter in the universe. Typically, when lens systems are modeled, they are treated as isolated systems, but this is not realistic. Most of the light bending will be from one galaxy, but there are many other galaxies along the line of sight that can contribute to overall deflection of the light. I have designed a mathematical framework that can be used to model gravitational lenses including both the main lens galaxy and all of the effects due to other galaxies along the line of sight.