About

Jason A. Douglas, PhD, MA, is Vice Chair and Associate Professor of Health, Society, & Behavior at UC Irvine Wen Public Health. He completed his environmental psychology doctoral training at the Graduate School and University Center of the City University of New York, where he worked with children from underserved communities in New York City and forest-fringe community residents in Jamaica to examine social and environmental inequities that challenge community health and wellbeing. He further honed his participatory research practice through a Robert Wood Johnson Foundation-funded postdoctoral research fellowship at Loyola Marymount University, working with a national cohort of community-based organizations to evaluate strategies for addressing health, education, and built environment disparities in underserved communities. His current research leverages community-based participatory action research to investigate and address environmental health disparities in Black and historically marginalized communities. His work includes structured observation of neighborhood assets and challenges, geospatial examinations of health and place, and studies on air pollution, urban heat-related health disparities, inequities in the siting of legal drug retail outlets, access to recreational spaces, and community organizing practices for health and wellbeing. Supported by state and federal funding, Douglas has developed and adapted innovative participatory methodologies, such as structured observation and neighborhood mapping, to examine public health challenges.

Research topics

• Astronomy
• Astrophysics
• Physics
• Optics

Selected publications

• NEA Detection Method with Neural Network in Sidereal Tracking

  Research in Astronomy and Astrophysics · 2025-06-13

  article

  Abstract Near-Earth Asteroids posed a threat to human civilization, making their monitoring crucial. As the demand for asteroid detection technology increased, precise detection of these celestial bodies became an urgent task to understand their characteristics and assess potential impact risks. To improve asteroid detection accuracy and efficiency, we proposed an advanced image processing method and a deep learning network for automatic asteroid detection. Specifically, we aligned star clusters and overlaid images to exploit asteroid motion rates, transforming them into object-like trajectories and improving the signal-to-noise ratio. This approach created the Asteroid Trajectory Image Data set under various conditions. We modified CenterNet2 network to develop AstroCenterNet by integrating Multi-channel Histogram Truncation for feature enhancement, using the SimAM attention mechanism to expand contextual information and suppress noise, and refining Feature Pyramid Network to improve low-level feature detection. Our results demonstrated a detection accuracy of 98.4%, a recall of 97.6%, a mean Average Precision of 94.01%, a false alarm rate of 1.6%, and a processing speed of approximately 17.86 frames per second, indicating that our method achieves high precision and efficiency.

  PublisherDOI

• Extended Hard X-Ray Emission in Highly Obscured AGNs

  The Astrophysical Journal · 2023-05-01 · 7 citations

  articleOpen access1st authorCorresponding

  Abstract Kiloparsec-scale hard (>3 keV) X-ray continuum and fluorescent Fe K α line emission has been recently discovered in nearby Compton-thick (CT) active galactic nuclei (AGNs), which opens new opportunities to improve AGN torus modeling and investigate how the central supermassive black hole interacts with and impacts the host galaxy. Following a pilot Chandra survey of nearby CT AGNs, we present in this paper the results of Chandra spatial analysis of five uniformly selected non-CT but still heavily obscured AGNs to investigate the extended hard X-ray emission by measuring the excess emission counts, excess fractions, and physical scales. Three of these AGNs show extended emission in the 3.0–7.0 keV band detected at >3 σ above the Chandra point-spread function with total excess fractions ranging from ∼8% to 20%. The extent of the hard emission ranges from at least ∼250 pc to 1.1 kpc in radius. We compare these new sources with CT AGNs and find that CT AGNs appear to be more extended in the hard band than the non-CT AGNs. Similar to CT AGNs, the amounts of extended hard X-ray emission relative to the total emission of these obscured AGNs are not negligible. Together with other AGNs detected with extended hard X-ray emission in the literature, we further explore potential correlations between the extended hard X-ray component and AGN parameters. We also discuss the implications for torus modeling and AGN feedback. Considering potential contributions from X-ray binaries (XRBs) to the extended emission, we do not see strong XRB contamination in the overall sample.

  PublisherOA PDFDOI

• Extended hard X-ray emission in highly obscured AGN

  arXiv (Cornell University) · 2023-02-09 · 1 citations

  preprintOpen access1st authorCorresponding

  Kilo-parsec scale hard ($>$ 3 keV) X-ray continuum and fluorescent Fe K$α$ line emission has been recently discovered in nearby Compton-thick (CT) active galactic nuclei (AGN), which opens new opportunities to improve AGN torus modeling and investigate how the central supermassive black hole interacts with and impacts the host galaxy. Following a pilot Chandra survey of nearby CT AGN, we present in this paper the Chandra spatial analysis results of five uniformly selected non-CT but still heavily obscured AGN to investigate the extended hard X-ray emission by measuring the excess emission counts, excess fractions, and physical scales. Three of them show extended emission in the 3.0-7.0 keV band detected at $>$ 3$σ$ above the Chandra PSF with total excess fractions ranging from $\sim$8% - 20%. The extent of the hard emission ranges from at least $\sim$250 pc to 1.1 kpc in radius. We compare these new sources with CT AGN and find that CT AGN appear to be more extended in the hard band than the non-CT AGN. Similar to CT AGN, the amounts of extended hard X-ray emission relative to the total emission of these obscured AGN are not negligible. Together with other extended hard X-ray detected AGN in the literature, we further explore potential correlations between the extended hard X-ray component and AGN parameters. We also discuss the implications for torus modeling and AGN feedback. Considering potential contributions from X-ray binaries (XRBs) to the extended emission, we do not see strong XRB contamination in the overall sample.

  PublisherOA PDFDOI

• Low gas-phase metallicities of ultraluminous infrared galaxies are a result of dust obscuration

  Nature Astronomy · 2022-05-26 · 20 citations

  articleOpen access
  PublisherOA PDFDOI

• Gas Phase Metallicities of Local Ultra-Luminous Infrared Galaxies Follow Normal Star-Forming Galaxies

  arXiv (Cornell University) · 2022-01-19

  preprintOpen access

  Despite advances in observational data, theoretical models, and computational techniques to simulate key physical processes in the formation and evolution of galaxies, the stellar mass assembly of galaxies still remains an unsolved problem today. Optical spectroscopic measurements appear to show that the gas-phase metallicities of local ultra-luminous infrared galaxies (ULIRGs) are significantly lower than those of normal star-forming galaxies. This difference has resulted in the claim that ULIRGs are fueled by metal-poor gas accretion from the outskirts\cite{Mannucci10}. Here we report on a new set of gas-phase metallicity measurements making use of the far-infrared spectral lines of [O{\sc iii}]52 $μ$m, [O{\sc iii}]88 $μ$m, and [N{\sc iii}]57 $μ$m instead of the usual optical lines. Photoionization models have resulted in a metallicity diagnostic based on these three lines that break the electron density degeneracy and reduce the scatter of the correlation significantly. Using new data from SOFIA and archival data from Herschel Space Observatory, we find that local ULIRGs lie on the mass-metallicity relation of star-forming galaxies and have metallicities comparable to other galaxies with similar stellar masses and star formation rates. The lack of a departure suggests that ULIRGs follow the same mass assembly mechanism as luminous star-forming galaxies and $\sim 0.3$ dex under-abundance in metallicities derived from optical lines is a result of heavily obscured metal-rich gas which has a negligible effect when using the FIR line diagnostics.

  PublisherDOI

• A Giant Loop of Ionized Gas Emerging from the Tumultuous Central Region of IC 5063*

  The Astrophysical Journal · 2021-08-01 · 10 citations

  articleOpen accessCorresponding

  Abstract The biconical radiation pattern extending from an active galactic nucleus (AGN) may strongly photoionize the circumnuclear interstellar medium (ISM) and stimulate emission from the narrow-line region (NLR). Observations of the NLR may provide clues to the structure of dense material that preferentially obscures the bicone at certain angles, and may reveal the presence of processes in the ISM tied to AGN accretion and feedback. Ground-based integral field units may study these processes via well-understood forbidden diagnostic lines such as [O iii ] and [S ii ], but scales of ∼tens of parsecs remain challenging to spatially resolve at these wavelengths for all but the nearest AGN. We present recent narrow-filter Hubble Space Telescope observations of diagnostic forbidden ([O iii ], [S ii ]) and Balmer (H α , H β ) lines in the NLR of IC 5063. This AGN’s jet inclination into the plane of the galaxy provides an important laboratory for strong AGN–host interactions. We find evidence for a low-ionization loop which emits brightly in [S ii ] and [N ii ], and which may arise from plume-like hot outflows that ablate ISM from the galactic plane before escaping laterally. We also present spatially resolved Baldwin–Phillips–Terlevich diagnostic maps of the IC 5063 NLR. These maps suggest a sharp transition to lower-ionization states outside the jet path, and that such emission is dominated by ∼10–40 pc clumps and filamentary structure at large (≫25°) angles from the bicone axis. Such emission may arise from precursorless shocks when AGN outflows impact low-density hot plasma in the cross cone.

  PublisherOA PDFDOI

• Gas Phase Metallicities of Local Ultra-Luminous Infrared Galaxies Follow Normal Star-Forming Galaxies

  Research Square · 2021-11-16

  preprintOpen access
  PublisherOA PDFDOI

• Spatially Resolved BPT Mapping of Nearby Seyfert 2 Galaxies

  The Astrophysical Journal · 2021-02-01 · 16 citations

  articleOpen access1st authorCorresponding

  Abstract We present spatially resolved Baldwin–Phillips–Terlevich (BPT) mapping of the extended narrow-line regions (ENLRs) of seven nearby Seyfert 2 galaxies, using Hubble Space Telescope narrowband filter imaging. We construct the BPT diagrams using ≤0.″1 resolution emission line images of [O iii ] λ 5007, H α , [S ii ] λλ 6717, 6731, and H β . By mapping these diagnostic lines according to the BPT classification, we dissect the ENLR into Seyfert, low-ionization nuclear emission-line (LINER), and star-forming regions. The nucleus and ionization cones are dominated by Seyfert-type emission, which can be interpreted as predominantly photoionization by the active galactic nucleus (AGN). The Seyfert nucleus and ionization cones transition to and are surrounded by a LINER cocoon, extending up to ∼250 pc in thickness. The ubiquity of the LINER cocoon in Seyfert 2 galaxies suggests that the circumnuclear regions are not necessarily Seyfert-type, and LINER activity plays an important role in Seyfert 2 galaxies. We demonstrate that spatially resolved diagnostics are crucial to understanding the excitation mechanisms in different regions and the AGN–host galaxy interactions.

  PublisherOA PDFDOI

• Is extended hard X-ray emission ubiquitous in Compton-thick AGN?

  arXiv (Cornell University) · 2020-08-05

  preprintOpen access1st authorCorresponding

  The recent Chandra discovery of extended $\sim$kpc-scale hard ($>$ 3 keV) X-ray emission in nearby Compton-thick (CT) active galactic nuclei (AGN) opens a new window to improving AGN torus modeling and investigating how the central super massive black hole interacts with and impacts the host galaxy. Since there are only a handful of detections so far, we need to establish a statistical sample to determine the ubiquity of the extended hard X-ray emission in CT AGN, and quantify the amount and extent of this component. In this paper, we present the spatial analysis results of a pilot Chandra imaging survey of 7 nearby ($0.006 < z < 0.013$) CT AGN selected from the Swift-BAT spectroscopic AGN survey. We find that five out of the seven CT AGN show extended emission in the 3-7 keV band detected at $>$ 3$σ$ above the Chandra PSF with $\sim$12% to 22% of the total emission in the extended components. ESO 137-G034 and NGC 3281 display biconical ionization structures with extended hard X-ray emission reaching kpc-scales ($\sim$ 1.9 kpc and 3.5 kpc in diameter). The other three show extended hard X-ray emission above the PSF out to at least $\sim$360 pc in radius. We find a trend that a minimum 3-7 keV count rate of 0.01 cts/s and total excess fraction $>$20% is required to detect a prominent extended hard X-ray component. Given that this extended hard X-ray component appears to be relatively common in this uniformly selected CT AGN sample, we further discuss the implications for torus modeling and AGN feedback.

  PublisherOA PDFDOI

• Emergence of an Ultra-Red Ultra-Massive Galaxy Cluster Core at z=4

  The Astrophysical Journal · 2020 · 10 citations

  • Physics
  • Astrophysics
  • Astronomy

  Recent simulations and observations of massive galaxy cluster evolution predict that the majority of stellar mass buildup happens within cluster members by z = 2, before cluster virialization. Protoclusters rich with dusty, star-forming galaxies (DSFGs) at z > 3 are the favored candidate progenitors for these massive galaxy clusters at z ~ 0. We present here the first study analyzing stellar emission along with cold dust and gas continuum emission in a spectroscopically confirmed z = 4.002 protocluster core rich with DSFGs, the Distant Red Core (DRC). We combine new Hubble Space Telescope and Spitzer data with existing Gemini, Herschel, and Atacama Large Millimeter/submillimeter Array observations to derive individual galaxy-level properties and compare them to coeval field and other protocluster galaxies. All of the protocluster members are massive (>1010 M ⊙), but not significantly more so than their coeval field counterparts. Within uncertainty, all are nearly indistinguishable from galaxies on the star-forming versus stellar mass main-sequence relationship and the star formation efficiency plane. Assuming no future major influx of fresh gas, we estimate that these gaseous DSFGs will deplete their gas reservoirs in ~300 Myr, becoming the massive quiescent ellipticals dominating cluster cores by z ~ 3. Using various methodologies, we derive a total z = 4 halo mass of ~1014 M ⊙ and estimate that the DRC will evolve to become an ultramassive cluster core of mass 1015 M ⊙ by z = 0.

  DOI

Frequent coauthors

• M. Béthermin

  38 shared

• Yashar Hezaveh

  38 shared

• M. Aravena

  Diego Portales University

  28 shared

• Daniel P. Marrone

  26 shared

• Justin Spilker

  26 shared

• Anthony H. Gonzalez

  24 shared

• J. D. Vieira

  University of Illinois Urbana-Champaign

  24 shared

• Matthew A. Malkan

  24 shared

Education

• Ph.D., Public Health

  University of California, Irvine

  2000

• M.A., Public Health

  University of California, Irvine

  1996