About Me

Education: I am currently a Ph.D. candidate in the Astrophysical & Planetary Sciences department at the University of Colorado Boulder, a graduate researcher at JILA, and an instructor for ASTR 2600: Introduction to Scientific Programming. I graduated from Truman State University in 2019 with Bachelor's degrees in physics and mathematics.

Research Interests: I am interested in the gravitational dynamics of bodies in orbit around compact objects. I currently work with Dr. Ann-Marie Madigan on the dynamics of eccentric disks in various astrophysical contexts including stars around supermassive black holes and planetesimals around white dwarfs. I also work with Dr. Smadar Naoz on stellar dynamics related to the Milky Way Galactic Center. Previously, I worked with Dr. Jason Dexter on thermal reprocessing models for changing-look quasars.

Publications: Check out my work on ADS!

Curriculum Vitae: Check out my CV here!

Research

The Formation of Eccentric Nuclear Disks from Gravitational Wave Recoil Kicks
The closest massive galactic neighbor, Andromeda, hosts a supermassive black hole that is surrounded by a lopsided, eccentric disk of stars. The merger of galaxies and the subsequent merger of the central supermassive black holes may be key in explaining the formation of these asymmetric stellar disks. The anisotropic emission of gravitational waves during the merger of two supermassive black holes causes a recoil kick to be imparted on the merger remnant. We showed in this 2021 letter that eccentric stellars disks with stars on apse-aligned orbits can directly form as a result of such a kick. We further showed in this 2023 paper that the surrounding star cluster following a recoil kick exhibits unique density and velocity structures that may be used to observationally detect recoiling supermassive black holes. Eccentric disks are able to enhance the rate of tidal disruption events, where stars become torn apart by the black hole due to strong tidal gravity. The rate can be 3 or 4 orders of magnitude higher in a lopsided disk compared to a symmetric one! This enhanced tidal disruption rate is indeed observed in merging/post-merger galaxies. This project is being carried out with my primary advisor Dr. Ann-Marie Madigan.

Evidence of a Recent Merger in the Galactic Center
We have applied the same mechanism of forming an eccentric disk via a gravitational wave recoil kick to explain the peculiar structure of the Milky Way Galactic Center. In the Galactic Center, there is a coherent disk of young stars between 0.05 and 0.5 pc, and the S-stars which are even closer in at < 0.04 pc are highly eccentric with a nearly isotropic distribution in inclination. We will show in a 2024 letter (in prep) that a low eccentricity, apse-aligned disk evolves to reproduce much of the eccentricity and inclination distributions of the S-star cluster and the surrounding disk within a few Myr suggesting a recent merger between an intermediate-mass black hole and Sagittarius A*. This research project is being conducted in collaboration with Dr. Smadar Naoz at UCLA.

White Dwarf Pollution from Natal Kicks
Many astrophysical bodies receive kicks, so the above dynamics are relevant for other contexts. A white dwarf receives a natal kick during its birth due to anisotropic mass loss during the asymptotic giant branch. As a result, an eccentric disk of planetesimals should surround the white dwarf after the kick. The eccentric debris disk can then efficiently throw planetesimals toward the white dwarf and increase the rate of planetesimal tidal disruption events. This mechanism can explain the abundance of polluted white dwarfs, white dwarfs with unexpectedly high amounts of heavy metals on their surface. This work will be presented in a 2024 letter (submitted). This project is being worked on with Dr. Ann-Marie Madigan and assisted by an CU undergraduate student, Selah McIntyre.

Reprocessing Models for Hypervariable Quasars
Quasars are extremely luminous active galactic nuclei, supermassive black holes which are actively feeding on their surrounding accretion disks. While standard accretion disk theory suggests that significant changes in the brightness of a quasar should take longer than ten thousand years, the Sloan Digital Sky Survey (SDSS) has discovered quasars that change in luminosity by up to factors of ~10 on much shorter timescales of months to years. These hypervariable quasars challenge our theories of accretion around supermassive black holes. One of the theories that can explain the hypervariable behavior is thermal reprocessing: the X-ray or extreme UV light from the quasar inner environment could be shining on an accretion structure that absorbs and re-emits the light at longer wavelengths. This can explain the large-amplitude, correlated variability we observe in the optical light curves of hypervariable quasars. We showed in a 2023 paper that the optical light curves of most of the hypervariable quasars observed by SDSS can be explained by thermal reprocessing in a thick accretion structure (rather than a thin disk). The standard thin disk is heavily disfavored by our model, and our work presented a first-order classification scheme for uncovering the likely reprocessing geometries of hypervariable quasars. This project was advised by Dr. Jason Dexter.

Community

Teaching:

CU Boulder
Spring 2024 Instructor for ASTR 2600: Intro to Scientific Computing
2021 - 2023 Lead Graduate Student Fellow
Fall 2022 TA for ASTR 5720: Galaxies
Spring 2020 TA for ASTR 1010: Intro to Astronomy
Fall 2019 TA for ASTR 3510: Observation and Instrumentation
Truman State University
Fall 2018 TA for PHYS 346: Observational Astronomy
Spring 2017 TA for PHYS 131: Intro to Astronomy

Research Mentoring:

Kalvyn Adams Evolution of a Double Eccentric Disk and Tidal Disruptions
Tom Alexander Stellar Disk Evolution Following an Out-of-plane Recoil Kick
Selah McIntyre Stars Engulfing Planets
Allie Christensen Formation of Eccentric Disks from a Black Hole Companion

Equity & Inclusion:
I have served on the Representation, Recruitment, and Retention Committee whose primary goal is to cultivate an inclusive department that celebrates diversity. We have been organizing information sessions and events for prospective students to recruit a more diverse graduate cohort, and we recently put together a diversity, equity, and inclusion (DEI) strategic plan for the department. I am currently the Lead Graduate Fellow, a liaison between the astrophysics community and the Center for Teaching and Learning. Through this role, I have been able to share many teaching resources that are cognizant of equity and inclusion with the department's instructors, teaching assistants, and learning assistants. I am currently writing a DEI teaching manual for the astrophysics department. In addition, I have supported the retention of students by serving as a mentor for the CU-Prime, Graduate Peer Mentoring, and McNair programs where participants often belong to under-represented minority groups and/or are first-generation college students.

Service:

2024 Longmont Astronomical Society Lecture
2023 ApJ Letters Referee
2020 - 2023 Welcome & Social Committee
2021 - 2022 Admissions Committee
2021 - 2022 Graduate Peer Mentor
2020 - 2022 CU-Prime Mentor
2019 - 2021 Diversity, Equity, and Inclusion (DEI) Committee
2019 - 2020 McNair Program Mentor
2019 - 2020 Graduate Curriculum & Concerns Committee
2019 - 2020 Observatory Committee
2019 - 2020 Observatory Open House Volunteer

Couresework

CU Boulder:
ASTR 5110 - Atomic and Molecular Processes
ASTR 5120 - Radiative and Dynamical Processes
ASTR 5140 - Astro/Space Plasmas
ASTR 5400 - Introduction to Fluid Dynamics
ASTR 5410 - Fluid Instabilities, Waves, and Turbulence
ASTR 5540 - Mathematical Methods
ASTR 5550 - Observations, Data Analysis, and Statistics
ASTR 5700 - Stellar Astrophysics
ASTR 5710 - High-Energy Astrophysics
ASTR 5720 - Galaxies
ASTR 5820 - Origin and Evolution of Planetary Systems

Truman State University:
PHYS 320 – Electronics
PHYS 375 – Vibrations and Waves
PHYS 382 – Mathematical Physics
PHYS 386 – Classical Mechanics
PHYS 446 – Advanced Laboratory
PHYS 482 – Electricity & Magnetism
PHYS 486 – Thermodynamics and Statistical Mechanics
PHYS 518 – Astrophysics
PHYS 580 – Quantum Mechanics
MATH 335 – Game Theory
MATH 451 – Algebraic Structures
MATH 461 – Advanced Calculus
MATH 465 – Differential Geometry
MATH 488 – Relativity Theory
MATH 564 – Advanced Linear Algebra
CS 170 – Introduction to Computer Science (Python)
CS 181 – Foundations of Computer Science (Java)
CS 250 – Systems Programming (C and C++)
STAT 290 – Statistics
STAT 478 – Regression Analysis