Eric Bellm

I am the current Survey Scientist (and founding Project Scientist) for the Zwicky Transient Facility (ZTF), an optical time-domain survey based at Palomar Observatory. Using a new camera with a 47 square degree field of view and fast readout, ZTF surveys the Northern Sky with unprecedented survey speed. It is now conducting a high cadence, wide area survey using novel scheduling algorithms that I developed.

ZTF achieved first light in October 2017 and is now in routine survey operations. It is regularly discovering young supernovae, rare classes of transients, variable stars and compact binaries, and solar system objects.

Half of the ZTF observing time is used for public surveys. Since June 2018, UW is using prototype Rubin Observatory tools to forward alerts from these surveys to community brokers in near real time. Bulk public access to these alerts is also available.

ZTF's Galactic Plane surveys provide fertile ground for identifying new compact binaries through their optical variability. I am conducting large-scale searches for these systems using powerful new data-mining tools.

Fermi has discovered many millisecond pulsars eclipsing and ablating low-mass companions--"Black Widow" and "redback" systems. My study of the unique redback MSP binary PSR J2129-0429 revealed that it has a heavy neutron star of 1.7 solar masses as well as an unexpected optical dimming on a timescale of years. The system sits in an unusual region of binary evolution phase space, exactly at the bifurcation period between converging and diverging binaries.

I regularly mentor, co-mentor, and collaborate with undergraduates, graduate students, and postdocs.

Current
Graduate students: David Wang, Andy Tzanidakis, Tom Wagg, Francisca Chabour Barra

Former
Postdoctoral Scholars: Rebecca Phillipson (2020-21; MPS ASCEND Fellow, 2021-22), now MSP ASCEND Fellow, Villanova; Keaton Bell (NSF Fellow, 2019-22), now faculty, Queen's College, CUNY; K. Azalee Bostroem (DIRAC Fellow, 2021-22), now LSSTC Catalyst Fellow, Arizona

Graduate students: Myles McKay (2020; single-quarter project), Mikhaela Gallardo (2019; summer project), Kellen Lawson (Univ. of Oklahoma) (2017; summer project)

Undergraduate students: Allison Crossland (2022-23), Giovanni Gollotti (2023), Rebecca Kyer (PreMAP 2019; 2019-21), now graduate school, Michigan State; Courtney Klein (with Jim Davenport; 2018-21), now graduate school, UC Irvine; AuDuyen Trinh (PreMAP, 2020); Simon Dawson (PreMAP, 2020); Abbas Jaffery (PreMAP, 2019); Konstantina Mason (PreMAP, 2019); Colton Peterson (PreMAP, 2019); Pricilla Dohrwardt (2019); Ryan Jackim (2018), now grad school at UBC; Franklin Marsh (2015, 2016), now at LinkedIn; Gandalf Saxe (2014); Talia Minear (2014); Rebecca Tang (2013)

My graduate and postdoctoral research included studies of gamma-ray bursts (GRBs) as well as high-energy instrumentation. I was a member of the NuSTAR commissioning team and flew a gamma-ray Compton telescope on stratospheric balloons.

With NuSTAR, I discovered an unusual extra component in the late-time X-ray afterglow of the ultra-long GRB130925A. In contrast, NuSTAR data for the bright nearby GRB130427A was consistent with emission by a single mechanism. In my dissertation, I evaluated multi-component "quasi-thermal" spectral models of the GRB prompt emission using RHESSI and Swift.

I participated in two campaigns of the balloon-borne gamma-ray Nuclear Compton Telescope, a predecessor to the COSI telescope. I maintained the flight control software and calibrated its effective area and polarization response for future observations of GRBs. Our 2009 New Mexico flight yielded the first image of the Crab Nebula by a compact Compton telescope. I led our 2010 Alice Springs campaign, directing shipping logistics, field operations, and interfaces with NASA and the media.

My campaign blog chronicled these adventures.