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Assistant Professor Peter Behroozi Wins Packard Fellowship

We are pleased to announce that Assistant Professor Peter Behroozi is part of a nationwide class of 22 early-career scientists to be awarded a Packard Fellowship. He is one of only four astronomers to get this five-year, $875000 award in 2019. You can read about the Packard HERE and Daniel Stolte's UANews story HERE

Part of Peter's research will be to try to understand how supermassive black holes form so quickly in the early universe. Observations by others have shown that by the time the universe is 700 million years old (5% of its current age), there already exist supermassive black holes large enough to power the most luminous quasars. Current physical models simply cannot make such large black holes on the timescales that Nature does. Peter and his graduate student, Haowen Zhang, will attack this problem in the following way: "We are going to use our experience in creating millions of virtual universes containing billions of galaxies and apply it to generating new synthetic universes, this time filled with black holes,"  Peter says. "We will then compare our results to observational data of active, supermassive black holes and quasars at different times as well as to black holes closer to home."

Please join us in congratulating  Peter. Peter joins Astronomy/Steward Professors Dennis Zaritsky (1997) and Xiaohui Fan (2004) as Packard winners. 

picture courtesy of Arizona Illustrated

Arizona Illustrated and Telumundo Visit Mt Lemmon Sky Center

In October Arizona Illustrated visited the Mount Lemmon Sky Center and did a feature on the public observing done there. You can see the video HERE. In addition, a similar spot was filmed during summer shutdown 2019, in Spanish, and shown on Telemundo.

(The photo is a screenshot from the Arizona Illustrated video.)

2019-2020 First-Year Grad Students

Another academic year has begun. Here are two photos of our first-year class. Photo 1 is the formal photo and Photo 2 is the proof that our students can fly.

From left to right: Quentin Socia, Logan Pearce, Cameron White, Spencer Scott, Victoria Jones, Jiachuan Xu, Justin Kang, Pranjal Rajendra Singh and Zuyi Chen.  

(Photos are courtesy Michelle Cournoyer.) 

The SAGUARO Project and Multi-Messenger Astronomy

Since April 2019 , Michael Lundquist and David Sand of Steward Observatory along with a team of astronomers from Northwestern University have partnered with Eric Christensen (LPL) and the Catalina Sky Survey (CSS) on the Searches After Gravitational-waves using ARizona Observatories (SAGUARO) project. This project uses the Steward Observatory Mount Lemmon 60” telescope to search for optical counterparts to gravitational wave events using the CSS asteroid survey. CSS provides two years worth of historical imaging that is used with image subtraction to more easily identify new events.  Many in the Steward community are involved, with the team, in the follow-up observations of these events.

In April 2019  the Advanced LIGO and Virgo facilities turned on and began their third observing run looking for the gravitational wave signals indicative of the mergers of compact objects such as neutron stars and black holes. While no optical counterparts to the gravitational wave event were found, by anyone in the world, the SAGUARO team was able to test and improve its telescope response to the LIGO alerts. In this test, it discovered two new supernovae (unrelated to detected gravitational waves) and utilized the Large Binocular Telescope Observatory to spectroscopically classify one promising optical counterpart from another group. This object, PS19eq, was also determined to be a supernova and unfortunately not a kilonova.

To date, only one optical counterpart to a gravitational wave event, AT2017gfo, has been found. Part of the reason for this is that the gravitational wave observatories can only localize events to tens or hundreds (or even thousands) of square degrees.The image shows the gravitational wave localization of this object as well as field centers of observed images. Teams such as SAGUARO are able to image many square degrees of sky quickly, looking for things that have changed brightness, and then to use large telescopes for spectroscopic followup of the most likely transient sources.

This is a new and exciting field that will open up our understanding of heavy element production in the universe, provide independent measurements of cosmological parameters, and provide clues to the structure of neutron stars. The current LIGO and Virgo observing run continues through April 2020. SAGUARO represents the one of the most significant additions to the search for optical counterparts. The SAGUARO team is ready and able to follow up these detections searching for the elusive optical counterparts.

You can read the Saguaro paper HERE. The UA News article is HERE.

Congratulations New PhD's

Six of Astronomy's graduate students have received Doctorates this summer. We congratulate them and wish them the best in their new endeavors. What follows is a picture book of photos from their post-defense celebrations. 

Ekta Patel, May 9.

Deborah Schmidt, July 17.

Ramesh Mainali, July 25.

Junhan Kim, July 29.

David Lesser, July 31. 

Yifan Zhou, August 5. 

Recent Steward Ph.D. K. Decker French Wins the ASP's Trumpler Award

The Astronomical Society of the Pacific recently announced that K. Decker French (Ph.D. in 2017 from U.A. Dept. of Astronomy) has been awarded the 2019 Trumpler Award. It is given to "a recent recipient of the Ph.D. degree in North America whose research is considered unusually important to astronomy." 

You can read the A.S.P.'s press release HERE. The Carnegie article is HERE.

While at Arizona, Dr. French worked with Prof. Ann Zabludoff and contributed to a range of astronomical subfields, such as gravitational lensing, galaxy evolution, and the tidal disruption of individual stars by the massive black holes in the centers of galaxies. Her analyses included theoretical simulations, machine learning classifiers, and space- and ground-based imaging and spectroscopy that spanned ultraviolet to radio wavelengths. Dr. French's 2017 Ph.D. dissertation, "New Methods for Tracking Galaxy and Black Hole Evolution using Post-Starburst Galaxies," made important discoveries connecting the global star formation histories of galaxies to their gas content and to their galactic nuclei. She is now a Hubble Post-Doctoral Fellow at the Observatories of the Carnegie Institution of Washington.

Decker joins an impressive list of Stewardites who have won the Trumpler Award: Jennifer Scott (2005), Jill Bechtold (1988), John Hill (1986), and Gary Schmidt (1979). In addition professors and former professors Gurtina Besla (2013, Harvard), Jim Liebert (1980, Berkeley), and the above-mentioned Jill Bechtold have been so honored.

Congratulations, Decker, from all of us in the Astronomy Dept. and Steward Observatory.


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