83 citations · 323 across the 16 of their papers we have counts for
17 papers
A Comprehensive Analysis of WISE Mid-Infrared Colors for Obscured AGN Selection
Anika Goel, Samir Salim, Sara L. Ellison +4
In this paper, we investigate the robustness of WISE mid-IR color selection (W1-W2) for identifying obscured (Type 2) active galactic nuclei (AGNs) at low redshift (z<0.3), using a…
Galaxy Mergers in UNIONS -- II: Predicting Timescales in the Post-Merger Regime
Leonardo Ferreira, Sara L. Ellison, David R. Patton +3
Galaxy mergers are critical events that influence galaxy evolution by driving processes such as enhanced star formation, quenching, and active galactic nucleus (AGN) activity. Howe…
Unions with UNIONS: Using galaxy-galaxy lensing to probe galaxy mergers
Isaac Cheng, Jack Elvin-Poole, Michael J. Hudson +12
We use galaxy-galaxy lensing to investigate how the dark matter (DM) haloes and stellar content of galaxies with and $10 \leq \log_{10}(M_\star/\mathrm{M}_…
Galaxy evolution in the post-merger regime. III -- The triggering of active galactic nuclei peaks immediately after coalescence
Sara L. Ellison, Leonardo Ferreira, Robert Bickley +6
Galaxy mergers have been shown to trigger AGN in the nearby universe, but the timescale over which this process happens remains unconstrained. The Multi-Model Merger Identifier (MU…
Galaxy evolution in the post-merger regime I -- Most merger-induced in-situ stellar mass growth happens post-coalescence
Leonardo Ferreira, Sara L. Ellison, David R. Patton +5
Galaxy mergers can enhance star formation rates throughout the merger sequence, with this effect peaking around the time of coalescence. However, owing to a lack of information abo…
The effect of image quality on galaxy merger identification with deep learning
Robert W. Bickley, Scott Wilkinson, Leonardo Ferreira +3
Studies have shown that the morphologies of galaxies are substantially transformed following coalescence after a merger, but post-mergers are notoriously difficult to identify, esp…
Galaxy Mergers in UNIONS -- I: A Simulation-driven Hybrid Deep Learning Ensemble for Pure Galaxy Merger Classification
Leonardo Ferreira, Robert W. Bickley, Sara L. Ellison +7
Merging and interactions can radically transform galaxies. However, identifying these events based solely on structure is challenging as the status of observed mergers is not easil…
Galaxy merger challenge: A comparison study between machine learning-based detection methods
B. Margalef-Bentabol, L. Wang, A. La Marca +14
Various galaxy merger detection methods have been applied to diverse datasets. However, it is difficult to understand how they compare. We aim to benchmark the relative performance…
Interacting galaxies in the IllustrisTNG simulations -- VII: The connection between the most luminous active galactic nuclei and galaxy interactions
Shoshannah Byrne-Mamahit, David R. Patton, Sara L. Ellison +5
We investigate the connection between the most luminous active galactic nuclei (AGN), galaxy pairs, and post-mergers in the IllustrisTNG simulation. We select galaxy pairs and post…
The limitations (and potential) of non-parametric morphology statistics for post-merger identification
Scott Wilkinson, Sara L. Ellison, Connor Bottrell +4
Non-parametric morphology statistics have been used for decades to classify galaxies into morphological types and identify mergers in an automated way. In this work, we assess how…
X-ray AGNs with SRG/eROSITA: Multi-wavelength observations reveal merger triggering and post-coalescence circumnuclear blowout
Robert W. Bickley, Sara L. Ellison, Mara Salvato +6
Major mergers between galaxies are predicted to fuel their central supermassive black holes (SMBHs), particularly after coalescence. However, determining the prevalence of active g…
AGN in post-mergers from the Ultraviolet Near Infrared Optical Northern Survey
Robert W. Bickley, Sara L. Ellison, David R. Patton +1
The kinematic disturbances associated with major galaxy mergers are known to produce gas inflows, which in turn may trigger accretion onto the supermassive black holes (SMBH) of th…
A New Physical Picture for AGNs Lacking Optical Emission Lines
Christopher J. Agostino, Samir Salim, Sara L. Ellison +2
In this work, we use ~500 low-redshift (z ~ 0.1) X-ray AGNs observed by XMM-Newton and SDSS to investigate the prevalence and nature of AGNs that apparently lack optical emission l…
Galaxy mergers can rapidly shut down star formation
Sara L. Ellison, Scott Wilkinson, Joanna Woo +6
Galaxy mergers trigger both star formation and accretion onto the central supermassive black hole. As a result of subsequent energetic feedback processes, it has long been proposed…
The merger fraction of post-starburst galaxies in UNIONS
Scott Wilkinson, Sara L. Ellison, Connor Bottrell +4
Post-starburst (PSB) galaxies are defined as having experienced a recent burst of star formation, followed by a prompt truncation in further activity. Identifying the mechanism(s)…
Star formation characteristics of CNN-identified post-mergers in the Ultraviolet Near Infrared Optical Northern Survey (UNIONS)
Robert W. Bickley, Sara L. Ellison, David R. Patton +3
The importance of the post-merger epoch in galaxy evolution has been well-documented, but post-mergers are notoriously difficult to identify. While the features induced by mergers…
Convolutional neural network identification of galaxy post-mergers in UNIONS using IllustrisTNG
Robert W. Bickley, Connor Bottrell, Maan H. Hani +6
The Canada-France Imaging Survey (CFIS) will consist of deep, high-resolution r-band imaging over ~5000 square degrees of the sky, representing a first-rate opportunity to identify…