47 citations · 179 across the 18 of their papers we have counts for
18 papers
Thermal and non-thermal emission from supermassive black hole circumbinary disks: Disks, Coronae, Streams, and Cavities
Chris Nagele, Julian H. Krolik, Brooks E. Kinch +4
The search for electromagnetic signals from supermassive black hole (SMBH) binary systems is one of the cornerstones of multi-messenger astrophysics, complementing gravitational wa…
Simulation-Based Prediction of Black Hole Fe K Line Profiles
Chris Nagele, Julian H. Krolik, Brooks E. Kinch +1
One of the most useful spectral diagnostics of accreting black hole systems is the Fe K fluorescence line. Detected in many systems, it is often used to estimate the black hole…
Pulsational mass loss from supermassive stars creates the compact shells of Little Red Dots
Devesh Nandal, Igor Chilingarian, Chris Nagele +3
Little Red Dots (LRDs) have emerged as one of the central puzzles of the JWST era. Their spectra increasingly require dense gas close to the source, yet the physical origin of that…
Nitrogen enhancement of GN-z11 by metal pollution from supermassive stars
Sho Ebihara, Michiko S. Fujii, Takayuki R. Saitoh +4
Spectroscopic observations by the James Webb Space Telescope (JWST) have revealed young, compact, high-redshift () galaxies with high nitrogen-to-oxygen (N/O) ratios. GN-z11 at…
Simulation-Based Prediction of Black Hole Spectra: From to
Chris Nagele, Julian H. Krolik, Rongrong Liu +2
It has long been thought that black hole accretion flows are driven by magnetohydrodynamic (MHD) turbulence, and there are now many general relativistic global simulations illustra…
Ignition of weak interactions and r-process outflows in super-collapsar accretion disks
Aman Agarwal, Daniel M. Siegel, Brian D. Metzger +1
The collapse of rotating massive (~) stars resulting in hyperaccreting black holes (BHs; "collapsars") is a leading model for the central engines of long-duration gamma…
Simulation-Based Prediction of Black Hole X-ray Spectra and Spectral Variability
Rongrong Liu, Chris Nagele, Julian H Krolik +2
Data derived from general relativistic magnetohydrodynamic simulations of accretion onto black holes can be used as input to a postprocessing scheme that predicts the radiated spec…
The formation of black holes from rapidly accreting supermassive stars is not trivial: Simulations of thermonuclear pulsations and explosions
Chris Nagele, Hideyuki Umeda
In recent years, the formation and evolution of rapidly accreting supermassive stars has received significant attention in the hope of better understanding the origin of high redsh…
STELLA lightcurves of energetic pair instability supernovae in the context of SN2018ibb
Chris Nagele, Hideyuki Umeda, Keiichi Maeda
SN2018ibb is a recently observed hydrogen poor super-luminous supernova which appears to be powered by the decay of of radioactive nickel. This supernova has bee…
Metal-enriched Pair-instability supernovae: Effects of rotation
Hideyuki Umeda, Chris Nagele
In this paper we revisit metal-enriched rotating pair instability supernovae (PISNe) models for metallicities consistent with the Small Magellanic Cloud (SMC), the Large Magellanic…
Multiple channels for nitrogen pollution by metal enriched supermassive stars and implications for GN-z11
Chris Nagele, Hideyuki Umeda
GN-z11 is an unusually luminous high redshift galaxy which was recently observed to have strong nitrogen lines while at the same time lacking traditional signatures of AGN activity…
Evolution and explosions of metal enriched supermassive stars: proton rich general relativistic instability supernovae
Chris Nagele, Hideyuki Umeda, Koh Takahashi
The assembly of supermassive black holes poses a challenge primarily because of observed quasars at high redshift, but additionally because of the current lack of observations of i…
A machine learning approach to assessing the presence of substructure in quasar host galaxies using the Hyper Suprime-Cam Subaru Strategic Program
Chris Nagele, John D. Silverman, Tilman Hartwig +4
The conditions under which galactic nuclear regions become active are largely unknown, although it has been hypothesized that secular processes related to galaxy morphology could p…
Pulsations of primordial supermassive stars induced by a general relativistic instability; visible to JWST at z12
Chris Nagele, Hideyuki Umeda, Koh Takahashi +1
The origin of high-redshift quasars and their supermassive black hole engines is unclear. One promising solution is the collapse of a primordial supermassive star. Observational co…
Stability analysis of supermassive primordial stars: a new mass range for general relativistic instability supernovae
Chris Nagele, Hideyuki Umeda, Koh Takahashi +2
Observed supermassive black holes in the early universe have several proposed formation channels, in part because most of these channels are difficult to probe. One of the more pro…
Neutrino emission from the collapse of population III supermassive stars
Chris Nagele, Hideyuki Umeda, Koh Takahashi +2
We calculate the neutrino signal from Population III supermassive star collapse using a neutrino transfer code originally developed for core collapse supernovae and massive star co…
Pulsational pair-instability and the mass gap of Population III Black Holes: Effects of overshooting
Hideyuki Umeda, Takashi Yoshida, Chris Nagele +1
Since the discovery of GW190521, several proposals have been put forward to explain the formation of a black hole in the mass gap caused by (pulsational) pair-instability, $M = 65-…
The Final Fate of Supermassive Pop III Stars: Explosion or Collapse?
Chris Nagele, Hideyuki Umeda, Koh Takahashi +2
We investigate the possibility of a supernova in supermassive () population III stars induced by a general relativistic instability occurring in the helium…