Bayliss Research Group

Left: A, partial, impromptu group photograph taken at the June 2022 AAS Meeting in Pasadena, during a moderate COVID wave. 

We are a fully funded research group that currently consists of 3 PhD students and 7 undergraduates, working on a wide variety of projects. We work within several collaborations, including the Sloan Giant Arcs Survey (SGAS), the South Pole Telescope (SPT) Galaxy Clusters Group, JWST TEMPLATES ERS (JWST-ERS-01355), and the JWST LEGGOS project (JWST GO programs 03843 and 04125). We specialize in observational cosmology and astrophysics, using a wide range of observational facilities, both on the ground and in space

Recent news, results, and awards:

Current Bayliss Group Members

Grad Students:

Josh Roberson - UC PhD Candidate 

Raven Gassis - UC PhD Candidate 

Undergraduates:

Riley Owens (2020-) - UC Physics BS 2022

Lauren Elicker (2021-) - UC Physics BS 2023 

Prasanna Adhikari (2022-) - UC 3rd year Physics major 

Emmy Bursk (2023-) - UC Physics major 

Eli Meisel (2023-) - UC Physics BS 2024

Lyn Wang (2024-) - UC Physics major

Paul Smith (2024-) - UC Physics major

Joshua Tiju (2024-) -  UC Physics major 

Kristen Tucker (2024-) - UC Physics major 

James Leighton (2024-) - UC Physics major 

Nathan Hoffman (2024-) - UC Physics major 

Read More About Current Bayliss Group Member Projects

Grad Students:

Alex Navarre - PhD Candidate - Alex is measuring the properties of strongly lensed Lyman-alpha emitters using HST imaging that samples both broadband (stellar UV continuum) and narrow-band imaging (the ACS/WFC Ramp Filters) that isolates Lyman-alpha line emission. Alex has completed a thorough characterization of the lensed LAEs,  including morphological measurements with GALFIT and stellar population constraints using Prospector. His first paper is submitted, and he is currently working on a forward-modeling analysis that pushes source-plane models of each source through a family of strong lensing models pulled from the MCMC chain modeling analysis for each foreground lensing cluster. The forward modeling measurments will constrain source-plane (de-lensed) sizes for each source in both continuum (stellar light) and Lyman-alpha (subject to complex radiative transfer scattering off of neutral H). Alex also recently began a new analysis to generate spatially resolved SPS fits (again using  Prospector) of the Sunburst Arc (a strong, and strongly lensed, Lyman-alpha and Lyman continuum emitter).

Josh Roberson - PhD Candidate - Josh is using Prospector to constrain photometric redshifts and stellar populations in a variety of strongly lensed systems using a combination of HST and ground-based data from Magellan and Gemini. He has explored stellar population synthesis models for passive, red sequence populations in massive galaxy clusters, as well as extremely young stellar populations in strongly lensed, highly magnified UV-bright star-forming galaxies during the Epoch of Re-Ionization, and the stellar populations of X-ray emitting star-forming clumps at Cosmic Noon. His first project - being written up now - identifies two exceptionally bright, strongly lensed galaxies in the Epoch of Re-ionization, both of which are sufficiently magnified to allow HST imaging to resolve sub-structure in the form of separate star-forming clumps. Josh has reduced and analyzed ground-based NIR imaging (Ks) of these sources from Gemini-South/F2, and additional follow-up data (Gemini-South/GMOS spectroscopy, and NIR imaging from HST) will soon be available for both objects. Josh's second project is a study of the Phoenix Arc, which is a dwarf, starburst galaxy at Cosmic Noon (z=1.52) with X-ray emission (from HMXBs) detected by Chandra. He is performing a  Prospector SPS analysis to constrain the age of the stellar populations that host a substantial HMXB population.

Raven Gassis - PhD Candidate - Raven is comparing the positions, shapes, and alignments of different mass components (stars, gas, and DM) in a sample of strongly lensed galaxy clusters. He measures the different components using a combination of strong lens models, X-ray observations of the intra-cluster medium from Chandra X-ray Observatory, and HST imaging of the central extended intra-cluster light (ICL) and the central brightest cluster galaxies (BCGs). The Chandra data are also supporting a second analysis in which Raven has measured the merger fractions of the strong lensing cluster sample, which tests predictions for the ability of mergers to temporarily produce large increases in the merger cluster's strong lensing cross-section.  Raven is also beginning a new project to add velocityt dispersion measurements to his cluster sample. He designed multi-object slitmasks for a series of approved observing programs on GMOS on Gemini-North and Gemini-South to measure cluster galaxy velocities in this galaxy cluster sample, and will soon begin reducing the first data taken from those masks.

Undergraduates:

Riley Owens (2020-) - UC Physics BS 2022- Riley first worked on measuring the spatially resolved spectroscopic properties of the Sunburst Arc (a strongly lensed LyC leaking galaxy at z=2.4) that combines ground-based rest-UV spectroscopy from MagE on Magellan, and MUSE on the VLT, with HST imaging, which were used in Mainali et al. (2022). He is currently working as a research affiliate in my group at UC, recently submitting a journal article on the Lyman-alpha properties of the Sunburst Arc, and is working on a second paper analyzing the multiphase outflows in rest-UV spectra of the Sunburst Arc. Riley is also involved in work to follow-up a sample of strongly lensed Lyman alpha emitters from the eBOSS survey, looking to identify candidate lensed LyC leaking galaxies based on double-peaked Lyman-alpha emission. Riley is the PI on an approved Fast Turnaround Gemini program to image a few of these systems, as a pilot study.

Lauren Elicker (2021-) - UC Physics BS 2023 -  Lauren is working on a project measuring the X-ray point source (AGN) population in Chandra observations of fields containing strong lensing galaxy clusters, and measuring the fraction of strong lensing cluster BCGs that host an X-ray AGN (Elicker et al., in prep). She was awarded a DAWN-IRES fellowship at the Cosmic DAWN Center at the University of Copenhagen during summer 2022, and during summer 2023 has been leading a small cohort of undergraduates (w/ Rose Hewald and Nicholas Younker) on a project to install, run, and document the JWST data reduction pipelines using beta versions of cookbooks produced by the TEMPLATES ERS program. With Rose and Nicholas, Lauren co-authored a "beginners guide" to reducing JWST NIRSpec data that will be published along with the TEMPLATES guides and cookbooks. Lauren is beginning a SULI fellowship at Los Alamos National Lab in Fall 2023.

Prasanna Adhikari (2022-) - UC 3rd year Physics major - Prasanna is measuring galaxy redshifts for thousands of ground-based spectra obtained from multi-object slit spectroscopy (mostly from IMACS on Magellan). He has begun to compute velocity dispersions for galaxy clusters using samples of cluster member redshifts, and using those velocity dispersions to compute virial mass estimates. Prasanna is now beginning to learn how to design and reduce multi-object spectroscopic data, working closely with my PhD student, Raven Gassis. 

Grayson Light (2022-) - UC 4th year Physics and Math major - Grayson started working with me in Fall 2022 on a project to develop a Python analysis code designed to measure the velocity power spectrum of a high resolution (R~24k) spectrum of Lyman-alpha emission measured from the LyC leaking Sunburst Arc. Grayson spent the summer of 2023 at an REU  program in mathematics at Florida International University.  

Rose Hewald (2023-) - Notre Dame 2nd year Physics major - Rose worked starting summer 2023 as a part of a small cohort (with Lauren Elicker and Nicholas Younker) to install and run JWST data reduction pipelines using beta versions of cookbooks produced by the TEMPLATES ERS program. With Lauren and Nicholas, Rose co-authored a "beginners guide" to reducing JWST NIRSpec data that will be published along with the TEMPLATES guides and cookbooks. 

Nikolas Younker (2023-) - UC 3rd year Aerospace Engineering and Astrophysics student - Nicholas joined my group during the summer of 2023 as was a part of a small cohort (working with Lauren Elicker and Rose Hewald ) to install and run JWST data reduction pipelines using beta versions of cookbooks produced by the TEMPLATES ERS program. With Lauren and Rose, Nicholas co-authored a "beginners guide" to reducing JWST NIRSpec data that will be published along with the TEMPLATES guides and cookbooks. 

Eli Meisel (2023-) - UC 4th year Physics major - Eli joined my group in Fall 2023 and they will begin reducing new JWST and HST data, and on running and documenting the JWST/HST pipelines.

Emmy Bursk (2023-) - UC 2nd year Physics major - Emmy joined my group in Fall 2023 and she will begin reducing new JWST and HST data, and on running and documenting the JWST/HST pipelines.

Former Bayliss Group Members

Postdocs:

Keunho Kim (2020-2023) - Arizona State PhD in 2020 - As a member of my group Keunho worked with the SGAS, SPT clusters, and TEMPLATES collaborations. He published a phase-space based analysis of galaxy quenching in massive SPT clusters from z~0.3 to z~1.1 (Kim et al. 2023a), and a spatially resolved analysis of the UV and ISM properties associate with LyC leakage in the Sunburst Arc (Kim et al. 2023b). He is currently working on a spatially resolved measurement of Xi_Ion using HST and JWST data of several lensed galaxies from the TEMPLATES program (Kim et al. ,in prep). Keunho is currently a postdoc at IPAC at Caltech.

Grad Students:

Alex Navarre - UC PhD 2024 

Savannah Koch - UC Physics MS 2023 - Now at Fidelity

Undergraduates:

Kyle Weeks (2019-2020) - UC Physics BS 2020 - Completed Physics MS at UC in 2022

Margo Adwani (2020-2021) - UC Physics BS 2021 - Graduate student at the University of Kentucky

Ethan Cronk (2020-2021) - UC Physics BS 2021 - Graduate student at the University of Maine

Owen Horecny (2020-2021)- UC Physics BS 2021 - Graduate student at Wayne State University

Cameron Pettry (2020-2021) - UC Physics BS 2021 - Graduate student at Cleveland State University.

Julia Wayne (2020) - Current UC IT Game Design Major 

Paula Vulić (2022) - Visting International Student from the University of Zagreb

Grayson Light (2022-2023) - UC 4th year Physics and Math major  

Rose Hewald (2023) - Notre Dame Physics major 

Nikolas Younker (2023-) - UC Aerospace Engineering and Physics major

And here are some nice, recent photos of collaboration meetings with heavy participation by my UC group members, including an unintentional SGAS Holiday Card.

Top Left: SGAS JWST ETC Workshop at Pitt-PACC (Oct 2022); Right: SGAS Face to Face Meeting in rural Ohio (Dec 2022);   Bottom Left: TEMPLATES Face to Face at UIUC (Jul 2023)