169 citations · 565 across the 14 of their papers we have counts for
14 papers
The long-term broad-line responsivity in MKN 110
D. Homan, A. Lawrence, M. Ward +7
We examine the long-term history of the optical spectrum of the extremely variable Active Galactic Nucleus (AGN) MKN 110. By combining various archival data with new data, we cover…
Through Andromeda and Beyond: AGN Optical Transient 'Sharov21' Revisited
A. Bruce, A. Lawrence, D. McLeod +1
We revisit a notable AGN known as `Sharov21', seen to undergo a dramatic outburst in 1992, brightening by a factor of thirty over a period of approximately one year. A simple micro…
Behaviour of the MgII 2798AA Line Over the Full Range of AGN Variability
David Homan, Chelsea L. Macleod, Andy Lawrence +2
We investigate the responsiveness of the 2798AA Mg II broad emission line in AGN on timescales of several years. Our study is based on a sample of extremely variable AGN as well as…
The tidal disruption event AT2017eqx: spectroscopic evolution from hydrogen rich to poor suggests an atmosphere and outflow
M. Nicholl, P. K. Blanchard, E. Berger +24
We present and analyse a new tidal disruption event (TDE), AT2017eqx at redshift z=0.1089, discovered by Pan-STARRS and ATLAS. The position of the transient is consistent with the…
The 'Big Dipper': The nature of the extreme variability of the AGN SDSS J2232-0806
Daniel Kynoch, Martin J. Ward, Andy Lawrence +3
SDSS J2232-0806 (the 'Big Dipper') has been identified as a 'slow-blue nuclear hypervariable': a galaxy with no previously known active nucleus, blue colours and large-amplitude br…
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…