Publications (30)
Curriculum-Based Soft Actor-Critic for Multi-Section R2R Tension Control
Shihao Li, Jiachen Li, Christopher Martin +3
Precise tension control in roll-to-roll (R2R) manufacturing is difficult under varying operating conditions and process uncertainty. This paper presents a curriculum-based Soft Act…
Coevolution of halo and quasar properties in dense environments: CARLA J1017+6116 at z=2.8
Sofia G. Gallego, Simona Mei, Christopher Martin +4
Radio-loud active galactic nuclei, in particular radio-loud quasars, are fueled by accretion onto supermassive black holes and are among the most energetic sources in the Universe.…
Quenching, bursting and galaxy shapes: colour transformation as a function of morphology
Camila de Sá-Freitas, Thiago Signorini Gonçalves, Reinaldo R. de Carvalho +6
Different mechanisms for quenching star formation in galaxies are commonly invoked in the literature, but the relative impact of each one at different cosmic epochs is still unknow…
The Dark Matter Distributions in Low-Mass Disk Galaxies. I. H Observations Using the Palomar Cosmic Web Imager
Nicole C. Relatores, Andrew B. Newman, Joshua D. Simon +6
Dark-matter-only simulations predict that dark matter halos have cusp-like inner density profiles, while observations of low-mass galaxies have found a range of inner slopes that a…
Performance Analysis for Almost Periodic Piecewise Linear Systems with Application to Roll-to-Roll Manufacturing Control
Christopher Martin, Edward Kim, Enrique Velasquez +2
An almost periodic piecewise linear system (APPLS) is a type of piecewise linear system where the system cyclically switches between different modes, each with an uncertain but bou…
Algorithm-Relative Trajectory Valuation in Policy Gradient Control
Shihao Li, Jiachen Li, Jiamin Xu +3
We study how trajectory value depends on the learning algorithm in policy-gradient control. Using Trajectory Shapley in an uncertain LQR, we find a negative correlation between Per…
The Dark Matter Distributions in Low-Mass Disk Galaxies. II. The Inner Density Profiles
Nicole C. Relatores, Andrew B. Newman, Joshua D. Simon +8
Dark matter-only simulations predict that dark matter halos have steep, cuspy inner density profiles, while observations of dwarf galaxies find a range of inner slopes that are oft…
Millimeter and Submillimeter Survey of the R Corona Australis Region
Christopher Groppi, Craig Kulesa, Christopher Walker +1
Using a combination of data from the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO), the Arizona Radio Observatory Kitt Peak 12m telescope and the Arizona Radio…
The FLASHES Survey I: Integral Field Spectroscopy of the CGM around 48 QSOs
Donal O'Sullivan, Christopher Martin, Mateusz Matuszewski +5
We present the pilot study component of the Fluorescent Lyman-Alpha Structures in High-z Environments (FLASHES) Survey; the largest integral-field spectroscopy survey to date of th…
Spitzer view on the evolution of star-forming galaxies from z=0 to z~3
Pablo G. Perez-Gonzalez, George H. Rieke, Eiichi Egami +11
We use a 24 micron selected sample containing more than 8,000 sources to study the evolution of star-forming galaxies in the redshift range from z=0 to z~3. We obtain photometric r…
A "blue ring nebula" surrounding a thousands of years old stellar merger
Keri Hoadley, Christopher Martin, Brian D. Metzger +7
Stellar mergers are a brief-lived but common phase in the evolution of binary star systems. Among the many astrophysical implications of these events include the creation of atypic…
Model Predictive Path Integral Control for Roll-to-Roll Manufacturing
Christopher Martin, Apurva Patil, Wei Li +2
Roll-to-roll (R2R) manufacturing is a continuous processing technology essential for scalable production of thin-film materials and printed electronics, but precise control remains…
Spectroscopic Confirmation of a Coma Cluster Progenitor at z ~ 2.2
Behnam Darvish, Nick Z. Scoville, Christopher Martin +17
We report the spectroscopic confirmation of a new protocluster in the COSMOS field at 2.2, COSMOS Cluster 2.2 (CC2.2), originally identified as an overdensity of narrowb…
Still at Odds with Conventional Galaxy Evolution: The Star Formation History of Ultra-Diffuse Galaxy Dragonfly 44
Kristi A. Webb, Alexa Villaume, Seppo Laine +7
We study the star formation history (SFH) of the ultra-diffuse galaxy (UDG) Dragonfly 44 (DF44) based on the simultaneous fit to near-ultraviolet to near-infrared photometry and hi…
A Vigorous Explorer Program
Martin Elvis, Matthew Beasley, Roger Brissenden +47
Explorers have made breakthroughs in many fields of astrophysics. The science from both these missions contributed to three Nobel Prizes - Giacconi (2002), Mather, and Smoot (2006)…
Adaptive Trajectory Bundle Method for Roll-to-Roll Manufacturing Systems
Jiachen Li, Shihao Li, Christopher Martin +2
Roll-to-roll (R2R) manufacturing requires precise tension and velocity control under operational constraints. Model predictive control demands gradient computation, while sampling-…
MDR-DeePC: Model-Inspired Distributionally Robust Data-Enabled Predictive Control
Shihao Li, Jiachen Li, Christopher Martin +2
This paper presents a Model-Inspired Distributionally Robust Data-enabled Predictive Control (MDR-DeePC) framework for systems with partially known and uncertain dynamics. The prop…
Similar Scaling Relations for the Gas Content of Galaxies across Environments to z ~ 3.5
Behnam Darvish, Nick Z. Scoville, Christopher Martin +3
We study the effects of the local environment on the molecular gas content of a large sample of log(/) 10 star-forming and starburst galaxies with speci…
Spatially Resolved Stellar Spectroscopy of the Ultra-diffuse Galaxy Dragonfly 44. III. Evidence for an Unexpected Star-Formation History
Alexa Villaume, Aaron J. Romanowsky, Jean Brodie +6
We use the Keck Cosmic Web Imager integral-field unit spectrograph to: 1) measure the global stellar population parameters for the ultra-diffuse galaxy (UDG) Dragonfly 44 (DF44) to…
The Properties of Ultraviolet-Luminous Galaxies at the Current Epoch
Timothy M. Heckman, Charles G. Hoopes, Mark Seibert +23
We have used the first matched set of GALEX and SDSS data to investigate the properties of a sample of 74 nearby galaxies with far-ultraviolet luminosities chosen to overlap the lu…
An LLM-Assisted Multi-Agent Control Framework for Roll-to-Roll Manufacturing Systems
Jiachen Li, Shihao Li, Christopher Martin +3
Roll-to-roll manufacturing requires precise tension and velocity control to ensure product quality, yet controller commissioning and adaptation remain time-intensive processes depe…
End-to-end ground calibration and in-flight performance of the FIREBall-2 instrument
Vincent Picouet, Bruno Milliard, Gillian Kyne +18
The payload of the Faint Intergalactic Redshifted Emission Balloon (FIREBall-2), the second generation of the FIREBall instrument (PI: C. Martin, Caltech), has been calibrated and…
Quenching or Bursting: the Role of Stellar Mass, Environment, and Specific Star Formation Rate to 1
Behnam Darvish, Christopher Martin, Thiago S. Gonçalves +3
Using a novel approach, we study the quenching and bursting of galaxies as a function of stellar mass (), local environment (), and specific star-formation rate (sSFR) u…
Circumgalactic Ly Nebulae in Overdense Quasar Pair Regions Observed with the Palomar Cosmic Web Imager
Jessica S. Li, Carlos J. Vargas, Donal O'Sullivan +8
The recent discovery of enormous Ly nebulae (ELANe), characterized by physical extents kpc and Ly luminosities erg s, provide a unique opportunity…
Halo Occupation Distribution Modeling of Green Valley Galaxies
Elisabeth Krause, Christopher M. Hirata, Christopher Martin +2
We present a clustering analysis of near ultraviolet (NUV) - optical color selected luminosity bin samples of green valley galaxies. These galaxy samples are constructed by matchin…
SN 2023zaw: an ultra-stripped, nickel-poor supernova from a low-mass progenitor
Kaustav K. Das, Christoffer Fremling, Mansi M. Kasliwal +34
We present SN 2023zaw a sub-luminous ( mag) and rapidly-evolving supernova ( days), with the lowest nickel mass (…
Keck/Palomar Cosmic Web Imagers (KCWI/PCWI) Reveal an Enormous Ly Nebula in an Extremely Overdense QSO Pair Field at
Zheng Cai, Erika Hamden, Matt Matuszewski +10
Enormous Ly nebulae (ELANe) represent the extrema of Ly nebulosities. They have detected extents of kpc in Ly and Ly luminosities erg s. Th…
Spatially-resolved stellar kinematics of the ultra diffuse galaxy Dragonfly 44. I. Observations, kinematics, and cold dark matter halo fits
Pieter van Dokkum, Asher Wasserman, Shany Danieli +8
We present spatially-resolved stellar kinematics of the well-studied ultra diffuse galaxy (UDG) Dragonfly 44, as determined from 25.3 hrs of observations with the Keck Cosmic Web I…
Spatially Resolved Stellar Kinematics of the Ultra-Diffuse Galaxy Dragonfly 44: II. Constraints on Fuzzy Dark Matter
Asher Wasserman, Pieter van Dokkum, Aaron J. Romanowsky +9
Given the absence of directly detected dark matter (DM) as weakly interacting massive particles, there is strong interest in the possibility that DM is an ultra-light scalar field,…
Catalogs of Hot White Dwarfs in the Milky Way from GALEX's Ultraviolet Sky Surveys. Constraining Stellar Evolution
Luciana Bianchi, Boryana Efremova, James Herald +4
We present comprehensive catalogs of hot star candidates in the Milky Way, selected from GALEX far-UV (FUV, 1344-1786 AA) and near-UV (NUV, 1771-2831 AA) imaging. The FUV and NUV p…