Hey, that’s me!

Welcome to my webpage, traveler.  Rest here, stay for a while.

I am the sixth year graduate student at the Department of Astronomy at the Ohio State University.  I have done work on a whole lot of things during my time here at (t)OSU!  Check me out on ADS to see all my papers.  You can also find my CV here. Most of my work during grad school has involved studying Active Galactic Nuclei (AGNs).  This work can be split up into two broad topics – the variability of the accretion disc and the changing-look phenomenon.  I’ve also worked on other projects focused on transients, namely work with the Large Binocular Telescope (LBT) search for failed supernovae (SNe) and tidal disruption events (TDEs) discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN). 

Artist’s impression of an accretion disc surrounding a SMBH. Above the SMBH, an X-ray “lamppost” drives disc variability – or does it? Credit: NASA/JPL-Caltech.

Accretion discs

The current understanding of AGN discs includes an X-ray “lamppost” that sits above the disc and variably illuminates it.  This variable illumination causes the disc to vary in UV/optical wavelengths.  Our recent work attempts to map the disc itself using a sample of multi-filter AGN lightcurves, and we find that many of our maps are inconsistent with a lamppost being the only source of variability.  Moreover, our maps are dominated by slow-moving fluctuations that are more consistent with being generated by the disc itself.  These findings could have huge impacts in how we understand AGN variability, as intrinsic disc fluctuations have been hypothesized and simulated yet never directly observed.  See more here!

In addition to studying more AGNs with this technique (including a soon-to-be-published paper on Mrk 817, the target of AGN STORM 2), I’m planning to expand on this work to study other aspects of AGN variability, like the broad line region and perhaps even the corona – can the disc drive the lamppost?



I’ve recently published a paper examining 20 years of multi-wavelength variability of the nearby NGC 5273.  We especially concentrated the variability with respect to the exciting yet poorly understood “changing-look” phenomenon, where broad emission lines appear and/or disappear over the course of a few years.  While all AGNs are variable, this specific type of variability is extremely important in that it poses a direct challenge to the “unified model”, where the presence/absence of broad lines is thought to be a line-of-sight effect.  Moving back to NGC 5273, we report that the AGN changed-look at least once during the period from 2001 to 2022 (more tightly, between 2010 and 2014), and we claim that it may have done so multiple times based on its multi-wavelength variability.  However, due to lack of consistent spectroscopic observations, we cannot definitively say that the AGN changed-look more than once, though perhaps future observations will prove (or disprove!) our claim.   In any case, this study was a great experience and allowed me to personally handle data ranging from the near-infrared to hard X-rays, which is especially useful when AGNs emit at all these wavelengths.


The LBT search for failed supernovae

Artist’s impression of a red supergiant dying as a failed supernova. A peculiar thing about the failed SN candidate that we found – it wasn’t a red supergiant – it was blue!  If proven to be a true failed SN, this could have tons of implications for our understanding of what kinds of stars die as failed SN.  Credits: NASA, ESA, and P. Jeffries.

I’ve also worked on stellar mass BHs with Professors Christopher Kochanek and Krzysztof Stanek on finding failed supernova (SN) candidates with the OSU-co-owned Large Binocular Telescope (LBT).  Failed SNe are what happen when stars are too massive to explode as SN and instead implode into BHs.  We reported the discovery of a new candidate failed SN and updated the failed SN fraction based on our observations.  Check it out!

The LBT search for failed SN is also just a great dataset for successful SNe.  The survey has been ongoing since 2008, and so we now have up to 15 years of archival observations that can be used to measure and constrain the pre-SN variability of the progenitor star.  We do exactly this for SN 2023ixf, finding no evidence for optical variability in our data.  We also put upper limits outbursts that we may have missed due to gaps in observation – namely, if the progenitor exceeded 5x its initial luminosity in an outburst, we would have been able to detect it because its long-lasting effects on the dust surrounding the progenitor.  Check out the paper for more info.


Artist’s depiction of a TDE. ASASSN-18jd may have been one of these – or it may have been a very, very strange outburst of an AGN. Credit: NASA/JPL-Caltech

Tidal Disruption Events

Going from stellar mass BHs back to SMBHs, I’ve also done work on TDEs detected by ASAS-SN.  TDEs are the luminous flares that occur when a star gets ripped apart by the tidal forces of a SMBH and is accreted.  My first, first-author paper at OSU was characterizing ASASSN-18jd, a peculiar event that is not quite a TDE, and not quite an AGN.  At the time, ASASSN-18jd was unique in its peculiarity, but newer work has shown there to be a handful of ambiguous nuclear transients (ANTs) with similar in-between-TDE-and-AGN properties.


With all the different work I’ve done, you could say I’m a Jack of all trades!