Dr. Christopher Churchill
EDUCATION
ADDITIONAL INFORMATION (opens new tab)
ORCID Hompage (ORCID ID: 0000-0002-9125-8159)
RESEARCH
Dr. Churchill studies galaxy evolution using the technique known as "quasar absorption lines." He and his collaborators are studying the large extended gasous regions surrounding galaxies (known as the circumgalactic medium, CGM). The CGM can be up to 10 times larger than the galaxies themselves. Our observational goals are to obtain data that informs us about the spatial distribution and kinematic, chemical, and ionization conditions in the CGM. Our theoretical goals are to understand how galaxies are formed and how they evolve (their sizes, shapes, total stellar masses, etc.) with cosmic time. For the observed data, Dr. Churchill and his collaborators make extensive use of the Keck Observatory’s 10-meter telescopes, the Very Large Telescope facility, the Sload Digital Sky Survey, the Apache Point 3.5-meter telescope, the Lick 3-meter telescope, and the Hubble Space Telescope. For the theoretical interpretation of the data, hydrodynamic cosmological simulations are studied and compared to the data. For an introductory overview of this research that is suitable for the non-expert, see my page: Introduction to QSO Absorption Lines in Cosmological Simulations.Dr. Churchill has more recently begun researching artificial intelligence and machine learning applications for quasar absorptin line research. He and his students have focused on convolution neural networks with the goal of extracting the kinematic, chemical, and ionization conditions of absorbing gas in the CGM directly from quasar absorption line data (which would eliminate several human-labor time-intensive analysis steps).
GRADUATE TEXT BOOK
Dr. Churchill is author of a two-volume set of graduate-level astronomy text books entitled Quasar Absorption Lines. This 1300+ page set provides a detailed treatment of the topic of quasar absorption lines, including its historical development, scientific findings, theoretical foundations, and methods of analysis.
- Volume 1 (Introduction, Discoveries, and Methods) chronicles six decades of quasar spectroscopy. This Volume details the nature of the Ly-alpha forest, Lyman limit systems, damped Ly-alpha absorbers, deuterium (D/H), 21-cm absorbers, HI and HeII Reionization, the WHIM, and the multiple ionization phases of metal line absorbers. Galaxies and their connections to these absorbers are treated in depth, as are the taxonomy and classes of AGN/quasar spectra and their associated absorption lines.
- Volume 2 (Astrophysics, Analysis, and Modeling) treats the theory and analysis of absorption lines, including the physics of atomic transitions, gas and ionization physics, the cosmological model, radiative transfer, spectrograph design, analysis of spectra, and multi-component, multiphase chemical-ionization modeling. Pragmatic approaches to conducting and assessing absorber counts in large absorption line surveys is presented.
Here are links if you want to read the detailed, yet non-technical chapter abstracts | Volume 1 | Volume 2 |
TEACHING
Dr. Churchill has taught many undergraduate college level courses related to Astronomy and Physics, including “Astrophotography”, “Introduction to Astronomy”, “Life in the Universe”, “Into the Final Frontier” (a course on with focus on humanities explorations and future), and “Space Colonization”. He has also taught the graduate courses “Quasar Absorption Lines”, “The Interstellar Medium”, and “Stellar Spectroscopy” (which is partially a stellar atmospheres course). Courses taught at NMSU include:
- ASTR 110 Introduction to Astronomy
- ASTR 305 Life in the Universe | Link: Youtube Lecture Course
- ASTR 308 Into the Final Frontier | Link: Youtube Lecture Course
- ASTR 400 Independent Undergraduate Research
- ASTR 500 Graduate Seminar
- ASTR 545 Stellar Spectroscopy
- ASTR 598 Independent Graduate Research
- ASTR 600 Pre-Doctoral Research
- ASTR 605 Interstellar Medium
- ASTR 698 Quasar Absorption Lines | Link: My Textbook Homepage
- ASTR 700 Doctoral Research
GRADUATE STUDENTS
Current
- Mark Croom
- Bryson Stemock
PhD Awarded
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Elizabeth Klimek
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2024
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Exploring Causal Relationships Between Disk and Halo Processes in L* Galaxies at Cosmic Noon
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Planetarium Manager, South Carolina State Museum | |
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Rachel Marra |
2022 |
An Observer’s Examination of the Circumgalactic Medium Using Cosmological Simulations
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STEM Instructional Designer, Cornell University | |
| Rachel Vander Vliet | 2017 |
Observing the Baryon Cycle in Hydrodynamic Cosmological Simulations
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Software Engineer, NASA/STScI | |
| Nigel Mathes | 2017 |
The Vulture Survey of MgII and CIV Absorbers: Feasting on the Bones of Spectra Left to Die
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Chief Technology Officer, Morse Coorporation | |
| Nikole Nielsen | 2015 |
Tracing Galaxy Evolution Through Spatial and Kinematic Probes of the MgII Circumgalactic Medium
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Assistant Professor, University of Oklahoma | |
| Jessica Evans | 2011 |
MgII Quasar Absorption Line Systems as a Probe of Galaxy Structural and Kinematic Evolution
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Manager of Data Operations, Altair Data Resources | |
| Glenn Kacprzak | 2008 |
The Morphological, Kinematic, and Halo Gas Properties of MgII Absorption Selected Galaxies at Intermediate Redshift
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Professor, University of Swinburne | |
| Brandon Lawton | 2008 |
Diffuse Interstellar Bands in Damped Lyman-Alpha and Starburst Galaxies
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Project Scientist, Roman Science Communications, NASA/STScI | |
| Donald Lubowich | 2006 | The Galactic Deuterium Distribution | Coordinator of Astronomy Outreach, Hosfta University |