Department News

EUSO-SPB has been launched
April 24, 2017
EUSO-SPB launched today from Wanaka, New Zealand.

The EUSO-SPB instrument is carried by a superpressure balloon designed and launched by NASA’s Columbia Scientific Balloon Facility.

EUSO-SPB emerged from the JEM-EUSO project and uses the same principle of harnessing the earth's atmosphere to detect ultra high-energy cosmic rays. EUSO-SPB will observe the nitrogen fluorescence and Cherenkov photons produced by extensive air showers.

Department members: Angela V. Olinto
Scientific projects: Extreme Universe Space Observatory at the Japanese Module

The Halo Boundary of Galaxy Clusters in SDSS
April 24, 2017
A cluster formed in a Lambda-Cold Dark Matter simulation of structure formation.

Credit: Benedikt Diemer, Philip Mansfield
Prof. Andrey Kravtsov has participated in a recent study, which presents strong evidence for the physical edge of galaxy clusters using public data from the Sloan Digital Sky Survey.

The existence of such physical edges associated with sharp density drops due to the density caustics formed by accreting matter was predicted by the Department members Benedikt Diemer and Andrey Kravtsov in 2014, as part of Diemers PhD research. In a follow-up study, Diemer and Kravtsov have shown that the-edges can be considered to be natural physical boundary of dark matter halos that provide the gravitational "back-bone" for the structures observed in the galaxy distribution.

In the recent study, co-led by Eric Baxter - a former graduate student and currently a postdoctoral fellow at the University of Pennsylvania - the density drop associated with the halo edges was detected in the galaxy distribution around cluster centers.

Cosmological simulations show that massive galaxy clusters we see today have been accreting galaxies into their deep gravitational potential over the cosmic time. The process of galaxies "falling into" the cluster's potential well is a fairly clean and universal process that depends only on basic quantities of the cluster such as mass and accretion rate. One of the result of this simple picture is a sharp feature in the number density of galaxies around clusters - an imprint of the caustic formed by the infalling galaxies as they reach the first apocenter of their orbit, or the "edge" of the galaxy cluster. Researchers called the distance of the edge the "splashback" radius, as galaxies literally "splashing back" to that radius after they accrete onto cluster.

Together with collaborators in UPenn and UIUC, Andrey Kravtsov examined distribution of galaxies around a sample of clusters identified within the SDSS. The existence of the edge in the galaxy distribution within clusters was confirmed. In addition, the analysis revealed that properties of galaxies around cluster are sensitive to existence of the edge. Outside the splashback radius, the mix of red and blue galaxies was approximately independent of the distance from the cluster center, while inside the splashback radius the mix is abruptly changes towards a larger fraction of red galaxies. This indicates that the edge is a real dynamical feature and that majority of galaxies get transformed by the cluster environment from blue to red in less than one orbital period.

Related references:

Department members: Andrey V. Kravtsov
Department students: Philip Mansfield
Scientific projects: Sloan Digital Sky Survey

The Event Horizon Telescope's historic quest
April 13, 2017
The South Pole Telescope
This week the South Pole Telescope joined a global network of telescopes to take observations which aim to capture the highest-resolution image ever taken of the supermassive black hole at the center of the Milky Way.

Read more:

Department members: Bradford A. Benson, John E. Carlstrom
Scientific projects: South Pole Telescope

Prof. Angela Olinto has been awarded a NASA grant for "Concept Study of the Probe Of Extreme Multi Messenger Astrophysics (POEMMA)"
March 20, 2017
A research team led by Prof. Angela Olinto has been awarded a NASA grant for "Concept Study of the Probe Of Extreme Multi Messenger Astrophysics (POEMMA)". The team will define the instrument and mission details necessary for the Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) to enable, for the first time, charged particle astronomy with ultra-high energy cosmic rays (UHECRs), and to discover cosmogenic tau neutrinos as well as Ultra-High Energy Neutrinos of other flavors. POEMMA will make the first all-sky survey of UHECRs to reveal the sources of these extreme energy particles. UHECRs result from extreme conditions in the extragalactic universe that are not presently understood. POEMMA will combine the well-developed Orbiting Wide-field Light-collectorsi (OWL) concept with the recently proposed CHerenkov from Astrophysical Neutrinos Telescope (CHANT) concept to form a multi-messenger probe of the most extreme environments in the universe. POEMMA will detect UHECRs through the observation of particle cascades produced by the interaction of UHECRs with the Earth's atmosphere. Particle cascades excite nitrogen molecules in the atmosphere, which fluoresce in the ultraviolet (UV). Ultra-fast UV cameras record the fluorescence light produced by the particle cascades. The fluorescence technique has been perfected by the leading ground-based UHECR observatories, like the Pierre Auger Observatory and will begin to be observed from space observations shortly with EUSO-SPB.

The team will receive funds for an 18-month comprehensive study.

Department members: Angela V. Olinto
Scientific projects: Pierre Auger Observatory

Dr. Maria A. Weber has been Awarded a NSF Astronomy & Astrophysics Postdoctoral Fellowship
February 20, 2017
Dr. Maria A. Weber has been awarded a NSF Astronomy & Astrophysics Postdoctoral Fellowship (AAPF) for her proposal "Simulations of Magnetic Self-Organization and Flux Emergence in Low-Mass Stars Across the Tachocline Divide".

The NSF AAPF is a prized fellowship for highly qualified, recent doctoral scientists to carry out an integrated program of independent research and education. The program is intended to recognize early-career investigators of significant potential and to provide them with experience in research and education that will establish them in positions of distinction and leadership in the community.

Dr Weber's research will investigate the generation and emergence of magnetism in both fully convective M dwarfs and those with an imposed tachocline. It will be done in collaboration with Prof. Robert Rosner and Prof. Fausto Cattaneo, and Dr. Lucianne Walkowicz (Adler).

Dr Weber's education and outreach program will seek to increase public science literacy by inspiring scientific communication through 3D visualizations and training students in the skills necessary to deliver impactful public presentations. She will work in Adler's Space Visualization Lab (SVL) to create visualizations of her models for use in planetariums across the country. She will use 3D printing technology and virtual reality platforms as novel approaches to render her model outputs in a transportable way, benefiting tactile learners and reaching underserved groups through Adler's Galaxy Ride and UChicago's Life Long Learning (L3) program.

At UChicago, Dr. Weber will also develop a new program called SciComm Academy to mentor graduate and advanced undergraduate students in the design and delivery of public scientific talks about their research.

Department members: Fausto Cattaneo, Randall H. Landsberg, Robert Rosner

Diversity, Climate and Inclusion
February 17, 2017
The Diversity Committee is working to establish a public web presence that both details the department's commitment to diversity, and details activities undertaken by the department and the committee to promote diversity. Part of our attention and effort is focused on the climate of the department - a welcoming and inclusive climate is necessary (though not sufficient) for diversity. We are currently learning a great deal - from scientific literature that addresses issues of diversity, climate and inclusion, through to on-campus resources and efforts, from companion departments in the PSD, efforts than span the physical sciences, and organisations and events that are university wide. We are also tapping into broader resources, from professional organisations that intersect with us.

Eventually, much of this information will be archived and accessible through the diversity webpage; this should be in place by the end of the academic year 2017. In the meantime, here are some initial links to academic papers of interest, resources from across the university, and beyond. Also, stay tuned for another Tuesday pizza lunch talk on a diversity-related topic on February 21st.

Department Diversity Committee

University Resources:
Broader Resources:

Department members: Hsiao-Wen Chen, Daniel Fabrycky, Michael D. Gladders, Daniel E. Holz, Stephan S. Meyer
Department students: Gourav Khullar

Hsin-Yu Chen has been selected for a Cronin Fellowship
February 15, 2017
Please join me in congratulating Hsin-Yu Chen who has been selected for a Cronin Fellowship for 2017. The James Cronin Graduate Student Fellowship honors Professor Cronin though support of exceptional Ph.D. candidates. The Cronin Fellowship will support Hsin-Yu's research work up to the end of Summer quarter 2017, when she is expected to graduate.

Congratulations Hsin-Yu!

Angela V. Olinto,
Homer J. Livingston Professor and Chair Department of Astronomy & Astrophysics

Department members: Daniel E. Holz, Angela V. Olinto
Department students: Hsin-Yu Chen

Deflategate: Cold Wet Footballs, Ideal Gas Laws and Accusations of Cheating
February 8, 2017
Just in time for Super Bowl LI, students in the Space Explorers Program examined the physics and media frenzy of Deflategate. During the 2015 AFC championship game, NFL officials discovered that the pressure in several footballs used by the New England Patriots had decreased below permissible levels. This sparked a national controversy known as "Deflategate". The NFL (as well as many enemies the four-time Super Bowl champions Patriots had made in the football world) argued that the pressure drop could only be caused by cheating, especially because Tom Brady favors underinflated balls. (note: each team controls 12 footballs used when they are on offense mandated to be between 12.5 and 13.5 psi ). Patriots' fans argued that the drop was caused either by well known laws of physics, or by an elaborate NFL conspiracy.

Twenty-eight (28) high school students in KICP's Space Explorers program put these arguments to the test. Over the course of two weeks, students critically evaluated over a dozen arguments made by both sides, ranging from court documents, to college lectures, to tweets. Despite the strong opinions, contradictory claims, and often factually incorrect information found in these arguments, the Space Explorers managed to identify the critical questions that needed to be resolved to determine if Deflategate could be caused by purely innocuous physics and designed an experiment to address them. Their experiment revolved around measuring the effect that wetness had on the rate at which cold footballs warm up and increase in pressure.

To date their results are inconclusive. One trial found nothing suspicious about the pressure drop, and a second could not explain the low pressures in the Patriots' footballs. The Space Explorers themselves are split down the middle about how to interpret their results and will debate the best way to resolve this difference at the pre-Super Bowl Saturday class.

Department students: Philip Mansfield

KICP Space Explorer Naa Ashitey is the Quest Bridge Finalist for the University of Chicago
December 12, 2016
KICP Space Explorer Naa Ashitey (third from the left) is the Quest Bridge Finalist for the University of Chicago
Naa will join the UChicago Class of 2021 with a full four-year scholarship as a pre-med/psychology major. She has been a participant in the KICP Space Explorers Program for the past three years.

QuestBridge is a nonprofit program designed to assist high-achieving, academically motivated students from low-income backgrounds apply to top colleges around the nation. The program features the National College Match, in which students rank and apply to up to eight of QuestBridge's partner colleges. Students who are matched receive a generous four-year, no-loan scholarship.

Department members: Randall H. Landsberg

Mark SubbaRao to become IPS President-Elect
December 12, 2016
Congratulations to Associate, and Adler Planetarium Astronomer, Mark SubbaRao, who will become the President-Elect of the International Planetarium Society on January 1, 2017.

Mark SubbaRao won the recent International Planetarium Society (IPS) election and will assume the role of President-Elect of this prestigious society at the beginning of 2017. In two year's time he will become the President of the IPS for a two year term.

In his candidate's statement, Mark said "I am running for IPS President to help shape the future of the planetarium, this wonderful medium which can inspire the public like nothing else.
... If elected, I will focus on building a more active organization and expanding professional development opportunities. We will support research that demonstrates how effective the planetarium is."

Read the entire statement at the International Planetarium Society website.

Department members: Mark Subbarao

The Diversity Committee, and A Message from the President and Provost
December 2, 2016
The Department's newly formed Diversity Committee: Gourav Khullar, Daniel Holz, Hsiao-Wen Chen, Michael Gladders (Chair), Stephan Meyer, and Daniel Fabrycky.
The Department's newly formed Diversity Committee has just begun work, and we look forward to productive engagement with you on issues of diversity, inclusion, and department climate. Recent national events have led many in our departmental and broader university community to feel at risk, personally and professionally. We reaffirm the department's commitment to diversity and inclusion, and pledge to continue work to ensure that the Department of Astronomy and Astrophysics is a welcoming place to all. Both the President and Provost have released a statement regarding recent events, linked here.

Department members: Hsiao-Wen Chen, Daniel Fabrycky, Michael D. Gladders, Daniel E. Holz, Stephan S. Meyer
Department students: Gourav Khullar

Congratulations to Prof. Jacob Bean!
November 29, 2016
Prof. Jacob Bean
Dear Colleagues,

It is a pleasure to share with you the great news that Jacob Bean has been promoted to Associate Professor with tenure. Please join me in congratulating him!

All the best wishes,

Angela V. Olinto,
Homer J. Livingston Distinguished Service Professor and Chair Department of Astronomy & Astrophysics

Department members: Jacob L. Bean, Angela V. Olinto

Chicago high school students visit to experience "A day in the life of a scientist"
November 15, 2016
Professor Freedman talks about life as a scientist with the students.
University Professor Wendy Freedman has been invited to be the 2016-2017 Robert A. Pritzker Visiting Scientist in Residence at Chicago's Francis W. Parker School. The program aims to expand science education opportunities at Parker and foster an ongoing dialogue among students and teachers about current issues in science.

As part of her activities, Professor Freedman recently arranged for students to visit the Eckhardt Research Center for a discussion and tour of the KICP and Astronomy & Astrophysics labs and the Pritzker Nanofabrication Facility. Students visited the PNF and the KICP labs of Professor Erik Shirokoff (where Associate Fellow Peter Barry described the lab equipment and activities), and gathered in Professor Stephan Meyer's lab to see a camera that will be used in a balloon-borne experiment to detect cosmic ray showers. Professors Meyer and Freedman also spoke to students about various aspects of their research and their lives as scientists.

Department members: Wendy L. Freedman, Stephan S. Meyer, Erik Shirokoff

SPT-3G Camera Has Shipped to the South Pole
November 1, 2016
The SPT-3G camera is on its way to the South Pole! SPT-3G shipped from Fermilab on Friday October 28 and is expected to arrive at the South Pole on November 12, 2016. In February 2017, SPT-3G will begin a 4-year survey to make new, sensitive measurements of the cosmic microwave background (CMB). You can read more about the SPT-3G camera at "SPT-3G: A Next-Generation Cosmic Microwave Background Polarization Experiment on the South Pole Telescope".

Department members: Bradford A. Benson, John E. Carlstrom, Clarence L. Chang, Thomas Crawford, Stephan S. Meyer, Stephen Padin, Erik Shirokoff
Scientific projects: South Pole Telescope

Richard (Dick) H. Miller, pioneer of computational astrophysics, celebrated his 90th
September 2, 2016
Joan Palmer, Pat Palmer, Dick Miller, and Angela Olinto
Miller's research has dealt with a variety of topics. His early work focused on photometry of galaxies and the interpretation of results in stellar dynamical terms. A shift to n-body computational methods led to the discovery that the gravitational n-body problem is chaotic. In 1966, he proposed the design and construction of a large Michelson Stellar Interferometer with a 1-km baseline. He pioneered n-body computations with large numbers of particles (100 000) and the use of motion pictures to present and study the results. He developed the first n-body computation that showed spiral structure in a disk galaxy model (1970).

Department members: Richard H. Miller, Angela V. Olinto, Patrick E. Palmer

2016 Yerkes Summer Institute: Spy vs. Spy
August 16, 2016
Instructors: Camille Avestruz, Zoheyr Doctor, Gourav Khullar, Richard G. Kron, Randall H. Landsberg, James Lasker, Phil Mansfield, Sam Passaglia, Rebecca Pierce, Jason Poh.

The 2016 Yerkes Summer Institute (YSI) was filled with secrecy, deception, and espionage. At YSI, high school students in the Space Explorers program played the role of 20th-Century spies to handle secret information: revealing, concealing and distorting information. Through three day-long lab activities, the students explored connections between spying and science. In the "Secret Photos" lab, they studied angular size, resolution, and the film-development process in order to effectively gather information on "enemy operatives" using 35 mm cameras. In the "Radio Beams" lab, students designed, built, and tested a system to transmit audio via an amplitude-modulated (AM) laser, which allowed them to secretly communicate across long distances. Lastly, techniques to securely communicate were examined in the "Codes and Ciphers" lab, which also served as an introduction to modern cryptography. After cycling through these three day labs, the students broke into three new groups and took one of the labs a step further: one group doctored photographs to spread false information, another built AM radio transmitters and receivers, and the last created treasure hunts using codes and ciphers for the clues. Nighttime activities included: observations with the Yerkes telescopes, astrophotography, explorations of the constellations which focused on what current research can tell us about them (e.g. most know exoplanets were found by Kepler in the constellation Cygnus); and bad weather activities that included examinations of the veracity of viral internet photos, and stories of famous spies. The week's spy-themed activities not only introduced the students to the importance of privacy in the digital age, but also to the concepts and skills that are integral to any modern STEM career.

Department members: Richard G. Kron, Randall H. Landsberg
Department students: Zoheyr Doctor, Gourav Khullar, James Lasker, Philip Mansfield, Sam Passaglia, Jason Poh

Congratulations to Dr. Sean Johnson!
July 18, 2016
Dr. Sean Johnson
Congratulations to Sean Johnson for successfully defending his Ph.D. dissertation on "Studies of the relationship between galaxies and the inter/circum-galactic medium".

"Sean's thesis work casts new light on the intricate physical processes that drive the baryon cycles between star-forming regions and the intergalactic space. He led an ambitious survey of the galactic environments around chemically-enriched gas revealed in strong absorption against a background source. Sean's thesis sample represents the first of its kind in terms of both the scale and depth of galaxy survey data in quasar fields. It provides a pathfinder for future large-scale studies that will combine wide-field galaxy surveys with absorption spectroscopy to advance our understanding of chemical enrichment in low-density regions away from galaxies."
- Hsiao-Wen Chen, PhD advisor

Sean will be starting as a Carnegie-Princeton/Hubble fellow at Princeton in the fall.

Department members: Hsiao-Wen Chen
Department students: Sean Johnson

Congratulations to Dr. Asher Berlin!
July 8, 2016
Dr. Asher Berlin
Congratulations to Asher Berlin for successfully defending his Ph.D. dissertation on "Phenomenology of Particle Dark Matter".

"Asher's work has covered a broad range of topics related to dark matter and efforts to reveal its particle nature. He has worked on theory calculations relevant to underground and space-based dark matter searches and to searches for dark matter at the Large Hadron Collider. More recently, he has worked on non-standard ways in which dark matter may be have created in the early universe."
- Dan Hooper, PhD advisor

Asher has received a Post Doctoral Fellow position at SLAC.

Department members: Dan Hooper
Department students: Asher Berlin

Congratulations to Dr. Jonathan Richardson!
June 23, 2016
Dr. Jonathan Richardson
Congratulations to Jonathan Richardson for successfully defending his Ph.D. dissertation on "Experimental Constraints on the Exotic Shearing of Space-Time".

"Jon's thesis represents an important milestone. He's done much of the critical work to make the Holometer experiment a reality. It's the most sensitive instrument ever built to study tiny random jitters of space. In his thesis, he shows that the scale of random shear jitter is more than an order of magnitude less than the Planck length, which was the theoretical expectation. The experiment essentially rules out this effect. He's working with our team now to reconfigure the machine to study the other possibility, a jitter of rotational motion, at similar sensitivity. There is some hope that this effect in the laboratory may connect with the cosmic dark energy problem."
- Craig J. Hogan

Jonathan has received a Research Fellow position at the University of Michigan.

Department members: Craig J. Hogan, Stephan S. Meyer
Department students: Jonathan Richardson

Congratulations to Prof. Angela V. Olinto!
May 31, 2016
Angela V. Olinto named a Homer J. Livingston Distinguished Service Professor effective July 1, 2016.

Department members: Angela V. Olinto

Congratulations to Dr. Laura Kreidberg!
May 24, 2016
Dr. Laura Kreidberg
Congratulations to Laura Kreidberg for successfully defending her PhD dissertation on "Snapshots of Faraway Places: Intensive Atmosphere Characterization of Extrasolar Planets."

"Laura conducted the most ambitious observational programs ever on the topic of exoplanet atmospheres for her dissertation. She used large investments of Hubble and Spitzer Space Telescope time to measure exoplanet atmospheric compositions, thermal structures, energy budgets, and dynamics to understand planetary origins and physics. The papers resulting from her work are the new benchmarks in the field, and provide a foundation for studying the atmospheres of potentially habitable planets with future facilities."
- Jacob L. Bean, Ph.D. advisor

Starting this summer Laura will be a Junior Fellow of the Society of Fellows at Harvard University and a Fellow of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics.

Department members: Jacob L. Bean
Department students: Laura Kreidberg

Megan Bedell wins a Harper Dissertation Fellowship
May 22, 2016
Dear Colleagues,

Please join me in congratulating Megan Bedell for winning a William Rainey Harper Dissertation Fellowship for the 2016-17 academic year. The intent of the award is two-fold: to recognize significant achievement and to facilitate completion of the doctoral degree. This award, one of the University of Chicago's highest honors, recognizes significant achievement during graduate studies and professional promise.

Congratulations Megan!

Angela V. Olinto,
Homer J. Livingston Professor and Chair Department of Astronomy & Astrophysics

Department members: Jacob L. Bean, Angela V. Olinto
Department students: Megan Bedell

Wayne Hu elected to the National Academy of Sciences
May 3, 2016
Wayne Hu is the Horace B. Horton Professor in the Department of Astronomy & Astrophysics, Enrico Fermi Institute, and the College. His research focuses on the theory and phenomenology of structure formation in the Universe as revealed in Cosmic Microwave Background anisotropies, gravitational lensing, galaxy clustering and galaxy clusters.

Department members: Wayne Hu