56 citations · 246 across the 13 of their papers we have counts for
15 papers
A Comprehensive AGN Inventory for the Dwarf-Dominated RESOLVE and ECO Surveys: Mass-Dependent AGN Types and Occupation Fractions
Mugdha S. Polimera, Sheila J. Kannappan, Chris T. Richardson +7
We catalog Active Galactic Nuclei (AGN) in the volume- and mass-limited RESOLVE and ECO surveys using (i) the BPT plot with standard and alternate demarcations, (ii) the BPT plot a…
The Goldilocks Molecule: H Emission Lines Can Identify Elusive Dwarf AGN
Morgan Micharski, Chris Richardson
We propose using H emission lines as a novel diagnostic to identify dwarf AGN by running photoionization models incorporating active intermediate-mass black holes and using a…
Modeling the High-Energy Ionizing Output from Simple Stellar and X-ray Binary Populations
Kristen Garofali, Antara R. Basu-Zych, Benjamin D. Johnson +9
We present a methodology for modeling the joint ionizing impact due to a "simple X-ray population" (SXP) and its corresponding simple stellar population (SSP), where "simple" refer…
Modeling the molecular gas content and CO-to-H2 conversion factors in low-metallicity star-forming dwarf galaxies
L. Ramambason, V. Lebouteiller, S. C. Madden +8
Low-metallicity dwarf galaxies often show no or little CO emission, despite the intense star formation observed in local samples. Both simulations and resolved observations indicat…
Inferring the HII region escape fraction of ionizing photons from infrared emission lines in metal-poor star-forming dwarf galaxies
L. Ramambason, V. Lebouteiller, A. Bik +8
(abridged) Quantifying the ISM porosity to ionizing photons in nearby galaxies may improve our understanding of the mechanisms leading to Lyman Continuum photons leakage from galax…
RESOLVE and ECO: Finding Low-Metallicity Dwarf AGN Candidates Using Optimized Emission-Line Diagnostics
Mugdha S. Polimera, Sheila J. Kannappan, Chris T. Richardson +6
Existing star-forming vs. active galactic nucleus (AGN) classification schemes using optical emission-line diagnostics mostly fail for low-metallicity and/or highly star-forming ga…
Optical and JWST Mid-IR Emission Line Diagnostics for Simultaneous IMBH and Stellar Excitation in z~0 Dwarf Galaxies
C. T. Richardson, C. Simpson, M. S. Polimera +4
Current observational facilities have yet to conclusively detect intermediate mass black holes (IMBHs) that fill in the evolutionary gap between early unive…
Addressing the [O III]/H\b{eta} Offset of Dwarf Galaxies in the RESOLVE Survey
Chris T. Richardson, Mugdha S. Polimera, Sheila J. Kannappan +2
Metal poor dwarf galaxies in the local universe, such as those found in the RESOLVE galaxy survey, often produce high [O III]/H\b{eta} ratios close to the star forming demarcation…
An Atlas of Star-Forming Galaxy Equivalent Widths
Helen Meskhidze, Chris T. Richardson
We present an atlas of starburst galaxy emission lines spanning 10 orders of magnitude in ionizing flux and 7 orders of magnitude in hydrogen number density. Coupling SEDs from Sta…
Interpreting the Ionization Sequence in Star-Forming Galaxy Emission-Line Spectra
Chris T. Richardson, James T. Allen, Jack A. Baldwin +4
High ionization star forming (SF) galaxies are easily identified with strong emission line techniques such as the BPT diagram, and form an obvious ionization sequence on such diagr…
Interpreting the Ionization Sequence in AGN Emission-Line Spectra
Chris T. Richardson, James T. Allen, Jack A. Baldwin +2
We investigate the physical cause of the great range in the ionization level seen in the spectra of narrow lined active galactic nuclei (AGN). Mean field independent component anal…
Detecting the rapidly expanding outer shell of the Crab Nebula: where to look
Xiang Wang, G. J. Ferland, J. A. Baldwin +2
We present a range of steady-state photoionization simulations, corresponding to different assumed shell geometries and compositions, of the unseen postulated rapidly expanding out…
Classification and analysis of emission-line galaxies using mean field independent component analysis
James T. Allen, Paul C. Hewett, Chris T. Richardson +2
We present an analysis of the optical spectra of narrow emission-line galaxies, based on mean field independent component analysis (MFICA). Samples of galaxies were drawn from the…
The Nature of the H2-Emitting Gas in the Crab Nebula
C. T. Richardson, J. A. Baldwin, G. J. Ferland +4
Understanding how molecules and dust might have formed within a rapidly expanding young supernova remnant is important because of the obvious application to vigorous supernova acti…
H2 Temperatures in the Crab Nebula
E. D. Loh, J. A. Baldwin, G. J. Ferland +4
We used K-band spectra to measure the H2 excitation temperatures in six molecular knots associated with the filaments in the Crab Nebula. The temperatures are quite high - in the r…