Three of us (Cayenne Matt, CJ Harris, and I) attended Compact Objects in Michigan and Ontario 2024. This year it was hosted by Henry Ford College. Cayenne and CJ gave talks on their most recent research.

A group of around 40 people standing at the front of a lecture hall.
Conference picture for the 2024 Compact Objects in Michigan and Ontario conference.

A huge congratulations to former undergraduate group member Dr. Erica Hammerstein, who successfully defended her dissertation, titled “Population Studies of Tidal Disruption Events and Their Hosts: Understanding Host Galaxy Preferences and the Origin of the Ultraviolet and Optical Emission”.

screenshot of zoom presentation of dissertation defense. Left-hand panel shows powerpoint slide with amazing M-sigma plot. Right-hand panel shows room where defense is happening.
Erica Hammerstein defends her dissertation with a great M–σ figure.

The NANOGrav results keep on coming out! The following papers were officially published in the past few weeks.

NANOGrav and other PTAs found evidence for the gravitational wave background!

It has been over a year since posting a news item, but it has been a busy year. I will do bullet points of the most important stuff that has happened.

The evidence for gravitational wave background is huge news. It was a huge effort to get there from a team I have loved being a part of. I played significant roles in the “Astro Interpretation” paper and the “Evidence” paper.

So I am working my way back through all of the announcements I should have been keeping up with, but ya boy got paaaiiid! See more at my grant page.

All added up, these combine to a hair over $367k. Aaaaand I’ve spent it already.

I was in Bothell, WA right before AAS for a NASA LISA Study Team meeting. We put in some time thinking about the Science Ground Segment and the best ways for NASA to enable astrophysicists to extract science from LISA data. It’s really exciting to think about all the amazing stuff that will come from this. This was my first in-person NLST meeting as I joined the team shortly before COVID.

Group picture of 16 scientists in person with 3 virtually projected behind them.
NLST group picture. We were all holding our breaths while we briefly removed our masks for this picture.

Many thanks to our fearless leader, Kelly Holley-Bockelmann, and our host, Joey Key!

I forgot to mention that I am now a full NANOGrav member! (As of several months ago now.)

I am very excited to to say that the first NANOGrav paper I am on is out, and it’s a great one! It was led by Caitlin Witt and concerns the search for continuous wave (individually resolved long-lived) gravitational wave sources in the 12.5-year data.

Key figures:

Aitoff projection of the whole sky with colorscale showing upper limit to gravitational wave sources between 0.3e-14 and 1.0e-14. Stars show positions of pulsars clustered to one hemisphere.
Sky map of 12.5-year NANOGrav dataset upper limits to continuous wave sources. Map of CW strain 95% upper limits at f_GW = 7.65 × 10^{−9} Hz, the most sensitive frequency searched, for the 12.5-year data set. Pulsar locations are shown as white stars, with new pulsars added from the 12.5-year data set outlined in red. The most sensitive pixel is marked with a red dot, and is located at an RA of 19h07m30s and a Dec of −30◦00′00′′. In this region, where the our best-timed pulsars lie, our upper limits are nearly an order of magnitude more sensitive than the least sensitive pixel.
Plot of Gravitational wave strain upper limit as a function of frequency. The limit gets as low as 8e-15 at 7e-9 Hz.
All-sky CW strain 95% upper limits and associated error regions, with (red) and without (purple) a CRN included in the model. At low frequencies, modeling the CRN is necessary to avoid over-estimating our strain upper limits. We are the least sensitive to CWs at fGW =1/(1 year) due to the Earth’s orbit, creating the large feature seen in this and other figures.

It has been a long time since I have posted anything up here, but a lot has happened.

A bunch of papers and talks and grants that I need to upload here. Things are good, I just haven’t made updating the site a priority of late. Getting back to it now!

I will be giving an invited talk at the conference Supermassive Black Holes in Pucón, Chile 7–12 December 2020. By an amazing coincidence, this happens to be right before a total solar eclipse visible from Pucón!

There is still time to register for this sweet conference.

Image of a solar eclipse.
Map of the path of totality of the 14 December 2020 total solar eclipse.

Assuming the meeting will still be held, I will be giving an invited talk at the 8th Annual Giant Magellan Telescope Community Science Meeting, “Black Holes at all Scales” in Sedona, Arizona, being held 9–11 September 2020.

You should, by all means, sign up to attend. There is a great list of speakers.

Looks pretty cool!