The Power Of Postdocs

January 15, 2020 by Kristin Hanson

Physics and astronomy fellows help expand Johns Hopkins’ “outsized influence” on the field of cosmology

When it comes to the hottest issues in cosmology today — such as the Hubble Tension or better understanding the properties of dark matter — Johns Hopkins faculty and researchers stand at the front of the line.

Two men stand on either side of a large telescope pointed upward and to the left in the atrium of Johns Hopkins University's astronomy building.
(l-r) David Nataf and Jose Luis Bernal are the past and present recipients, respectively, of the Allan C. and Dorothy H. Davis Fellowship in physics and astronomy.

“Pound for pound, our cosmology faculty are as strong or stronger than anywhere else,” says Marc Kamionkowski, a professor in the Henry A. Rowland Department of Physics and Astronomy. He cites the presence of four members of the National Academies, a Nobel Laureate (Adam Riess), and someone who’s earned virtually every prize in the field except the Nobel (Charles Bennett). “If you leave aside the biomedical sciences, the highest collection of internationally recognized talent at Johns Hopkins is the cosmologists and astrophysicists in this department.”

Yet, Hopkins is at a disadvantage compared with its peers — the California Institute of Technology (CalTech), Massachusetts Institute of Technology (MIT), Harvard, Princeton, Stanford and others — in one key area. Although the department has several endowed fellowships that offer partial support for postdoctoral fellows, only one provides full funding.

“Johns Hopkins has a good reputation [in the field] — people know about the department and know they’re good at the work,” says Dominika Wylezalek, a former Hopkins postdoctoral fellow and current senior postdoctoral fellow at the European Southern Observatory (ESO). “But it is true that Hopkins is not known for having independent fellowships that can help ensure new, good ideas are coming in every year.”

“We have an outsized influence in the field, and we can do even more to advance the field if we have steady support for postdoctoral fellowships. Anyone who supports these kinds of fellowships will support the training of future leaders in this field.”

Marc Kamionkowski Professor in the Henry A. Rowland Department of Physics and Astronomy

Hopkins leaders, including university Provost Sunil Kumar, consider the endowment of independent physics and astronomy postdoctoral fellowships a high priority. Kumar has committed institutional support for three three-year fellowships to begin in fall 2020. The Krieger School is seeking additional support to ensure the availability of these fellowships in perpetuity.

“These postdoctoral fellows elevate the general level of intellectual activity taking place in the department,” says Professor and Department Chair Tim Heckman. “Not having a source to support these fellowships makes us less competitive with both our peers and other programs we’d objectively place ourselves above.”

Attracting a “Different Level” of Fellow

There are generally two kinds of postdoctoral fellowships in this field. In one, faculty apply for federal grants or other sources of funding and, once received, use some of that money to hire fellows. Although helpful in burnishing a young researcher’s resume, these fellowships have narrow focuses, usually exclusive to the research of the hiring faculty member. Independent postdoctoral fellows have the opportunity to determine their own research agenda and explore new ideas that can energize colleagues in their department.

A portrait of physics and astronomy postdoctoral fellow Jose Luis Bernal.
“[Hopkins] was one of my preferred places” to continue studies, says Jose Luis Bernal. The Davis Fellowship “was the final push I needed to have no doubt at all to come here.”
“To apply for this kind of fellowship, you have to showcase that you have a plan and set of ideas,” says Wylezalek, whose Hopkins experience was partially supported by funds from two different fellowships. “There’s a different level of applications the department will receive with this kind of [independent] fellowship.”

The Allan C. and Dorothy H. Davis Fellowship is the only award in the department of physics and astronomy that fully supports a postdoctoral fellow. It’s proven an effective tool in persuading top researchers to choose Hopkins’ department of physics and astronomy over distinguished peers. Jose Luis Bernal, who arrived at Hopkins in 2019, was considering offers from Harvard and the University of Cambridge and a NASA Postdoctoral Program fellowship at CalTech’s Jet Propulsion Laboratory.

“[Hopkins] was one of my preferred places from the very beginning,” says Bernal, who arrived from the Institute of Cosmos Science at the University of Barcelona. “The opportunity to have the Davis Fellowship was the final push I needed to have no doubt at all to come here.”

Some of Bernal’s work will focus on finding new ways to measure the expansion rate of the universe — the issue at the heart of the Hubble Tension. His office is in the same hallway as Kamionkowski’s research group, with which he met during an early visit to Hopkins and with whom he’ll collaborate during his fellowship.

“I look for people who are going to be interactive, inventive, and have ideas rather than waiting around to be told what to do,” Kamionkowski says. “Jose was entrepreneurial and interactive, but he also had the technical tools — the ability to do the work.”

“It’s Good to Have That Stimulus”

As Bernal begins his Davis Fellowship, his predecessor, David Nataf, sits in an office just one floor above him in Hopkins’ Bloomberg Physics and Astronomy Building.

Nataf’s research focuses on the history of the Milky Way galaxy and how that knowledge contributes to our understanding of the universe. Working with the Sloan Digital Sky Survey — a vast database of stars — Nataf and his collaborators determined that, when the Milky Way formed, it did so not from a large number of small star clusters but a small number of large clusters. In the process, his team was able to assess the quality of the Sloan survey’s data: what elements were measured reliably, in which contexts, for which stars, and how some calculations should be changed to support future projects. The work is informing predictions for data to be gathered by the James Webb Space Telescope, which will launch in 2021 to succeed the 30-year-old Hubble Space Telescope.

A portrait of physics and astronomy postdoctoral fellow David Nataf.
Postdoctoral fellows like David Nataf help enrich the undergraduate experience for physics majors. Two students he mentored are now pursuing graduate studies in astronomy and cosmology.

“[Nataf] did a huge amount of work, first proposing the problem, then discussing how best to go about it in analyzing the data. He had to step on some people’s toes who weren’t quite doing the right thing,” says Professor Rosemary Wyse, who worked with Nataf during Davis Fellowship. “It’s good to have that stimulus from these really active, broadly knowledgeable people.”

As his research took flight, Nataf invited some undergraduates along for the ride. Physics students interested in astronomy and cosmology can engage in research in large part due to the presence of postdoctoral fellows like Nataf. One of his students is now pursuing a graduate degree at MIT. Another is due to finish her Hopkins degree in 2020 and is applying to graduate schools in both the United States and United Kingdom.

“That might be one of the best things to come out of Hopkins for me,” Nataf says. “I feel very fortunate to work with these students.”

“This kind of opportunity enriches the physics major experience,” Wyse says. “That’s one of the draws of Hopkins — that undergraduates can do cutting-edge research.”

Contributing Ideas — And Leadership

Providing a training ground for up-and-coming scholar-leaders like Nataf is an important way Hopkins can contribute to the advancement of this area of science. Nataf and Bernal are among dozens of postdoctoral fellows Wyse and Kamionkowski have mentored in their respective tenures at Hopkins. The majority of those fellows have gone on to faculty positions at other institutions, won prestigious awards and prizes, and built bridges between Hopkins scholars and their counterparts in other departments.

“We have an outsized influence in the field, and we can do even more to advance the field if we have steady support for postdoctoral fellowships,” Kamionkowski says. “Anyone who supports these kinds of fellowships will support the training of future leaders in this field.”

One of those leaders is Wylezalek, who credits support from her Hopkins fellowships with enabling, among other things, the travel required to secure her position with the ESO two years ago. And her subsequent success at the ESO has led to an Emmy Noether Programme grant from the Deutsche Forschungsgemeinschaft — the German equivalent of the United States’ National Science Foundation. She’s in the process of hiring a full staff to launch her grant-supported work at the University of Heidelberg.

“I’m very excited about starting a research group and having the additional resources to work on the projects I have in mind, and some I started at Hopkins,” she says.

Make Your Gift

Interested in supporting independent postdoctoral fellows in physics and astronomy?

Topics: Foundations, Krieger School of Arts and Sciences, Fuel Discovery, Support Scholars