275 citations · 1.7k across the 61 of their papers we have counts for
9 papers · 2 filters
FRAMEx. V. Radio Spectral Shape at Central Sub-parsec Region of AGNs
Onic I. Shuvo, Megan C. Johnson, Nathan J. Secrest +4
We present results from the Very Long Baseline Array (VLBA) multi-frequency (1.6, 4.4, 8.6, 22 GHz), high-sensitivity (~25 microJy beam^-1), sub-parsec scale (<1 pc) observations a…
VLA FRAMEx. I. Wideband Radio Properties of the AGN in NGC 4388
Andrew J. Sargent, Travis C. Fischer, Megan C. Johnson +5
We present the first results from Karl G. Jansky Very Large Array (VLA) observations as a part of the Fundamental Reference Active Galactic Nucleus (AGN) Monitoring Experiment (FRA…
FRAMEx IV: Mechanical Feedback from the Active Galactic Nucleus in NGC 3079
Luis C. Fernandez, Nathan J. Secrest, Megan C. Johnson +1
Using the Very Long Baseline Array, we observed the active galactic nucleus (AGN) in NGC 3079 over a span of six months to test for variability in the two main parsec-scale radio c…
Exploring X-ray Properties of Low Metallicity Dwarf Galaxies
Jenna M. Cann, Kimberly A. Weaver, Ryan W. Pfeifle +3
One of the primary outstanding questions in extragalactic astronomy is the formation and early evolution of the supermassive black holes that are seen in nearly every massive galax…
NuSTAR Observations of Four Mid-IR Selected Dual AGN Candidates in Galaxy Mergers
Ryan W. Pfeifle, Kimberly Weaver, Shobita Satyapal +5
Mergers of galaxies are a ubiquitous phenomenon in the Universe and represent a natural consequence of the ``bottom-up'' mass accumulation and galaxy evolution cosmological paradig…
No Small Scale Radio Jets Here: Multi-Epoch Observations of Radio Continuum Structures in NGC 1068 with the VLBA
Travis C. Fischer, Megan C. Johnson, Nathan J. Secrest +2
We present recent Very Long Baseline Array (VLBA) 5 GHz radio observations of the nearby, luminous Seyfert 2 galaxy NGC 1068 for comparison to similar VLBA observations made on 199…
VaDAR: Varstrometry for Dual AGN using Radio interferometry
Emma Schwartzman, Tracy E. Clarke, Kristina Nyland +5
Binary and dual active galactic nuclei (AGN) are an important observational tool for studying the formation and dynamical evolution of galaxies and supermassive black holes (SMBHs)…
Radio-Optical Reference Catalog, version 1
Valeri V. Makarov, Megan C. Johnson, Nathan J. Secrest
The fundamental celestial reference frame (CRF) is based on two catalogs of astrometric positions, the third realization of the International Celestial Reference Frame (ICRF3), and…
The Messy Nature of Fiber Spectra: Star-Quasar Pairs Masquerading as Dual Type 1 AGNs
Ryan W. Pfeifle, Barry Rothberg, Kimberly A. Weaver +5
Theoretical studies predict that the most significant growth of supermassive black holes occurs in late-stage mergers, coinciding with the manifestation of dual active galactic nuc…