A5078735639- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Astrophysics and Star Formation Studies
- Relativity and Gravitational Theory
- Geophysics and Gravity Measurements
- Pulsars and Gravitational Waves Research
- Stellar, planetary, and galactic studies
- Black Holes and Theoretical Physics
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- History and Developments in Astronomy
- Cosmology and Gravitation Theories
Goddard Space Flight Center
2023-2025
Deleted Institution
2025
University of Maryland, Baltimore County
2024-2025
Western Michigan University
2023
Abstract We present multifrequency (5–345 GHz) and multiresolution radio observations of 1ES 1927+654, widely considered one the most unusual extreme changing-look active galactic nuclei (CL-AGNs). The source was first designated a CL-AGN after an optical outburst in late 2017 has since displayed considerable changes X-ray emission, including destruction rebuilding corona 2019–2020. Radio prior to 2023 show faint compact typical radio-quiet AGN. Starting February, 1927+654 began exhibiting...
Abstract We present results from a high-cadence multiwavelength observational campaign of the enigmatic changing-look active galactic nucleus 1ES 1927+654 2022 May to 2024 April, coincident with an unprecedented radio flare (an increase in flux by factor ∼60 over few months) and emergence spatially resolved jet at 0.1–0.3 pc scales. Companion work has also detected recurrent quasi-periodic oscillation (QPO) 2–10 keV band increasing frequency (1–2 mHz) same period. During this time, soft...
Recent discoveries from time-domain surveys are defying our expectations for how matter accretes onto supermassive black holes (SMBHs). The increased rate of short-timescale, repetitive events around SMBHs, including the newly-discovered quasi-periodic eruptions (QPEs), garnering further interest in stellar-mass companions SMBHs and progenitors to mHz frequency gravitational wave events. Here we report discovery a highly significant Quasi-Periodic Oscillation (QPO) an actively accreting...
We present results from a high cadence multi-wavelength observational campaign of the enigmatic changing look AGN 1ES 1927+654 May 2022- April 2024, coincident with an unprecedented radio flare (an increase in flux by factor $\sim 60$ over few months) and emergence spatially resolved jet at $0.1-0.3$ pc scales (Meyer et al. 2024). Companion work has also detected recurrent quasi-periodic oscillation (QPO) $2-10$ keV band increasing frequency ($1-2$ mHz) same period (Masterson al., 2025)....
Abstract Warm absorber spectra contain bound-bound and bound-free absorption features seen in the X-ray UV from many active galactic nuclei. The widths centroid energies of these indicate they occur outflowing gas, outflow can affect gas within host galaxy. Thus, warm mass energy budgets are great interest. Estimates for properties depend on models that connect observed strengths with density, composition, ionization state absorbing gas. Such assume heating come primarily strong continuum...
Abstract Time-dependent photoionization modeling of warm absorber (WA) outflows in active galactic nuclei can play an important role understanding the interaction between WAs and central black hole. The WA may be out equilibrium state because variable nature continuum. In this paper, with help time dependent modeling, we study how gas properties change it reacts to changing radiation fields. Incorporating a flaring incident light curve, investigate behavior using code that simultaneously...
We present multi-frequency (5-345 GHz) and multi-resolution radio observations of 1ES 1927+654, widely considered one the most unusual extreme changing-look active galactic nuclei (CL-AGN). The source was first designated a CL-AGN after an optical outburst in late 2017 has since displayed considerable changes X-ray emission, including destruction rebuilding corona 2019-2020. Radio prior to 2023 show faint compact not for radio-quiet AGN. Starting February 2023, 1927+654 began exhibiting...
Warm absorber spectra contain bound-bound and bound-free absorption features seen in the X-ray UV from many active galactic nuclei (AGN). The widths centroid energies of these indicate they occur outflowing gas, outflow can affect gas within host galaxy. Thus warm mass energy budgets are great interest. Estimates for properties depend on models which connect observed strengths with density, composition, ionization state absorbing gas. Such assume that heating come primarily strong continuum...
Time dependent photoionization modeling of warm absorber outflows in active galactic nuclei can play an important role understanding the interaction between absorbers and central black hole. The may be out equilibrium state because variable nature continuum. In this paper, with help time modeling, we study how gas changes it reacts to changing radiation fields. Incorporating a flaring incident light curve, investigate behavior using code that simultaneously consistently solves equations...