400 citations · 572 across the 6 of their papers we have counts for
10 papers · 1 filter
Deep modeling of quasar variability
Yutaro Tachibana, Matthew J. Graham, Nobuyuki Kawai +4
Quasars have long been known as intrinsically variable sources, but the physical mechanism underlying the temporal optical/UV variability is still not well understood. We propose a…
Gaia GraL: Gaia DR2 Gravitational Lens Systems. V. Doubly-imaged QSOs discovered from entropy and wavelets
A. Krone-Martins, M. J. Graham, D. Stern +22
The discovery of multiply-imaged gravitationally lensed QSOs is fundamental to many astronomical and cosmological studies. However, these objects are rare and challenging to discov…
The first high-redshift changing-look quasars
Nicholas P. Ross, Matthew J. Graham, Giorgio Calderone +3
We report on three redshift quasars with dramatic changes in their C IV emission lines, the first sample of changing-look quasars (CLQs) at high redshift. This is also the fi…
Understanding extreme quasar optical variability with CRTS: II. Changing-state quasars
Matthew J. Graham, Nicholas P. Ross, Daniel Stern +8
We present the results of a systematic search for quasars in the Catalina Real-time Transient Survey exhibiting both strong photometric and spectroscopic variability over a decadal…
Results of a systematic search for outburst events in 1.4 million galaxies
A. J. Drake, S. G. Djorgovski, M. J. Graham +5
We present an analysis of nine years of Catalina Surveys optical photometry for 1.4 million spectroscopically confirmed SDSS galaxies. We find 717 outburst events that were not rep…
Changing-Look Quasar Candidates: First Results from Follow-up Spectroscopy of Highly Optically Variable Quasars
Chelsea L. MacLeod, Paul J. Green, Scott F. Anderson +15
Active galactic nuclei (AGN) that show strong rest-frame optical/UV variability in their blue continuum and broad line emission are classified as "changing-look" AGN, or at higher…