KICP Seminars & Colloquia
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KICP Seminars & Colloquia, Fall 2019
Seminar schedule for Fall 2019September 30, 2019
Astronomy Special Seminar | Ore Gottlieb
University of Tel Aviv | Relativistic outflows in Neutron star mergers [Abstract] | October 1, 2019
Open Group seminar | Alex Krolewski
Berkeley | CMB Lensing Tomography at 0<z<2 with Galaxies from the unWISE Catalog [Abstract] | October 2, 2019
Wednesday colloquium | Hugh Lippincott
FNAL | Doping - not just for cyclists [Abstract] | October 4, 2019
Friday noon seminar | Susmita Adhikari
Stanford University | The Outer Profiles of Dark Matter Halos as a Probe of Cosmology, Dark Matter and Galaxy Evolution [Abstract] | October 9, 2019
Astronomy Colloquium | Daniel Stark
University of Arizona | Galaxies in the Reionization Era [Abstract] | October 10, 2019
Open Group seminar | Humna Awan
Rutgers University | Probing LSS with Large Galaxy Surveys: Systematics and Estimators [Abstract] | October 11, 2019
Friday noon seminar | Ben J P Jones
University of Texas at Arlington | Better Neutrinoless Double Beta Decay through Biochemistry [Abstract] | October 15, 2019
Open Group seminar | Austin Joyce
Columbia University | The view from the boundary: Bootstrapping inflationary correlators [Abstract] | October 16, 2019
Wednesday colloquium | Brian D Nord
Fermilab and UChicago | AI In the Sky: Implications and Challenges for the use of Artificial Intelligence in Astrophysics and in Society [Abstract] | October 17, 2019
Open Group seminar | Constance Mahony
University College London | Target Neutrino Mass Precision for Determining the Neutrino Hierarchy [Abstract] | October 18, 2019
Friday noon seminar | Carl Rodriguez
Harvard | How Do You Form a Binary Black Hole? [Abstract] | October 23, 2019
Astronomy Colloquium | John Grunsfeld
NASA | Hubble, Chicago, and the Search for Life in the Universe [Abstract] | October 25, 2019
Friday noon seminar | Sarah Wellons
Northwestern University | Simulating Galaxy Formation in the Early Universe [Abstract] | October 30, 2019
Wednesday colloquium | Yonatan Kahn
University of Illinois at Urbana-Champaign | Axions from the Lab to the Cosmos [Abstract] | November 1, 2019
Friday noon seminar | Yu Hai-Bo
University of California, Riverside | Self-Interacting Dark Matter [Abstract] | November 1, 2019
Open Group seminar | Joseph N. Burchett
UC - Santa Cruz | Galaxy ecosystems and the Cosmic Web [Abstract] | November 6, 2019
Astronomy Colloquium | TBA
| TBA | November 8, 2019
Friday noon seminar | Emmanuel S Schaan
Lawrence Berkeley National Laboratory | Lensing of the CMB and intensity maps: analogy with galaxy lensing and application to foreground cleaning [Abstract] | November 13, 2019
Wednesday colloquium | Wendy Freedman
University of Chicago | Tension in the Hubble Constant | November 15, 2019
Friday noon seminar | Katelyn Breivik
Canadian Institute for Theoretical Astrophysics | Binary evolution: a multi-messenger, multi-band puzzle [Abstract] | November 15, 2019
Open Group seminar | Nina Maksimova
Harvard | Next Generation N-body Cosmology with Abacus on the Summit Supercomputer [Abstract] | November 20, 2019
Astronomy Colloquium | TBA
| TBA | November 22, 2019
Friday noon seminar | Pitam Mitra
University of Washington | Single electron charge resolution with the first prototypes of DAMIC-M skipper CCD's [Abstract] | November 25, 2019
Open Group seminar | Jonathan Blazek
EPFL | Fun with Intrinsic Alignments: Exploring Beyond LCDM with Cosmological Surveys [Abstract] | December 4, 2019
Wednesday colloquium | Laura Newburgh
Yale University | New Probes of Old Structure: Cosmology with 21cm Intensity Mapping and the Cosmic Microwave Background [Abstract] | December 4, 2019
Astronomy Colloquium | TBA
| TBA | December 6, 2019
Friday noon seminar | Emmanuel Fonseca
McGill University | FRB Astrophysics in the Era of CHIME [Abstract] |
COLLOQUIA - October 2, 2019 | 3:30 PM | ERC 161 | Wednesday colloquium
Doping - not just for cyclists
Hugh Lippincott, FNAL
After a series of null results from the LHC and large direct detection experiments, dark matter remains frustratingly mysterious, and much of the canonical heavy WIMP parameter space is now ruled out. In this talk, I will give an update on the status of the LZ experiment, and discuss an idea to expand the parameter space that can be probed by large liquid xenon TPCs like LZ by adding hydrogen to the target, opening up sensitivity to WIMP masses well below 1 GeV. - October 9, 2019 | 3:30 PM | ERC 161 | Astronomy Colloquium
Galaxies in the Reionization Era
Daniel Stark, University of Arizona
Over the past decade, deep infrared images have pushed the cosmic frontier back to just 500 million years after the Big Bang, delivering the first large sample of galaxies at redshifts 77 galaxies from ALMA, Magellan, and Keck has begun to sharpen our understanding of this reionization process while also providing a glimpse of the physical nature of early galaxies. The spectral features we are detecting at z>7 are unlike what has been seen at lower redshifts, hinting at a population of low mass galaxies undergoing frequent bursts of star formation. Surveys at lower redshift have begun to reveal insight into the ionizing efficiency of this population of low mass galaxies, providing quantitative constraints on the production and escape of ionizing radiation. In this talk, I will review the latest in observational efforts to understand galaxies in the reionization-era and discuss remaining challenges that must be addressed in advance of JWST. - October 16, 2019 | 3:00 PM | ERC 161 | Wednesday colloquium
AI In the Sky: Implications and Challenges for the use of Artificial Intelligence in Astrophysics and in Society
Brian D Nord, Fermilab and UChicago
Artificial Intelligence (AI) refers to a set of techniques --- like machine learning, deep learning, and data science --- that rely on the data itself to develop models of observed phenomena. AI algorithms have a long history of development, and there has been a recent resurgence in their research and deployment, marked by extraordinary results in many contexts, including scientific ones. However, these algorithms are far from a panacea for our challenging data-modeling tasks.
Three major changes have revolutionized the role of data in our lives: 1) the increased availability of large data sets; 2) advancements in computing hardware; and 3) insights for new mathematical and algorithmic techniques. Because of these elements, AI now permeates society --- from the promise of self-driving vehicles to entertainment choices to cancer-detection and criminal justice. Moreover, in the last few years, it has had substantial impacts on molecular chemistry, particle physics, and more recently astronomy. AI is more than likely here to stay, as well as grow as an important technique in our science toolboxes.
Nevertheless, AI has significant challenges for reaching its full potential for scientific impact --- namely, uncertainty quantification, interpretability, bias, and hybridization with physical models. These challenges also plague implementations in other contexts throughout society. Given these challenges, how do we implement these algorithms in a responsible, careful, and systematic way?
We'll discuss these topics in the context of deep learning and its application to modern astronomical surveys. Finally, we'll discuss the implications for the widespread use of AI in society. - October 23, 2019 | 3:30 PM | ERC 161 | Astronomy Colloquium
Hubble, Chicago, and the Search for Life in the Universe
John Grunsfeld, NASA
The Hubble Space Telescope story has been a fascinating study in public policy, engineering, ethics, and science. The Hubble is perhaps the most productive scientific instrument ever created by humans. In May 2009, a team of astronauts flew to the Hubble Space Telescope on space shuttle Atlantis. On their 13-day mission and over the course of 5 spacewalks they completed an extreme makeover of the orbiting observatory. They installed the Wide Field Camera-3, the Cosmic Origins Spectrograph, repaired the Advanced Camera for Surveys and the Space Telescope Imaging Spectrograph, as well as a number of maintenance activities. These Hubble spacewalks are considered the most challenging and daring efforts ever of people working in space. This mission also carried a bit of the University of Chicago with it on board. Now, still going strong on orbit, the Hubble has a full complement of instruments capable of performing state-of-the-art observations from the near infra-red to the ultraviolet end of the spectrum. In this talk we will present a narrative of the adventure, and a look at what some of the scientific results may offer in the search for life beyond Earth in our Solar System. - October 30, 2019 | 3:30 PM | ERC 161 | Wednesday colloquium
Axions from the Lab to the Cosmos
Yonatan Kahn, University of Illinois at Urbana-Champaign
As the gravitational evidence for the existence of dark matter accumulates inexorably, the particle identity of dark matter remains mysterious. One of the best theoretically-motivated dark matter candidates, with some of the most interesting experimental signals, is the axion. Axions are expected to interact very weakly with electromagnetism, which leads to the possibility of detecting axions through conversion to photons in strong magnetic fields. I will review the status of several new experiments and searches aiming to detect axion dark matter on Earth, in astrophysical systems, and produced in the laboratory. - November 6, 2019 | 3:30 PM | ERC 161 | Astronomy Colloquium
TBA
TBA, - November 13, 2019 | 3:30 PM | ERC 401 | Wednesday colloquium
Tension in the Hubble Constant
Wendy Freedman, University of Chicago - November 20, 2019 | 3:30 PM | ERC 161 | Astronomy Colloquium
TBA
TBA, - December 4, 2019 | 3:30 PM | ERC 161 | Wednesday colloquium
New Probes of Old Structure: Cosmology with 21cm Intensity Mapping and the Cosmic Microwave Background
Laura Newburgh, Yale University
Current cosmological measurements have left us with deep questions about our Universe: What caused the expansion of the Universe at the earliest times? How did structure form? What is Dark Energy and does it evolve with time? New experiments like CHIME, HIRAX, and ACTPol are poised to address these questions through 3-dimensional maps of structure and measurements of the polarized Cosmic Microwave Background. In this talk, I will describe how we will use 21cm intensity measurements from CHIME and HIRAX to place sensitive constraints on Dark Energy between redshifts 0.8 -- 2.5, a poorly probed era corresponding to when Dark Energy began to impact the expansion history of the Universe. I will also discuss how we will use data from new CMB instruments to constrain cosmological parameters like the total neutrino mass and probe structure at late times. - December 4, 2019 | 3:30 PM | ERC 161 | Astronomy Colloquium
TBA
TBA,
FRIDAY NOON SEMINARS - October 4, 2019 | 12:00 PM | ERC 401 | Friday noon seminar
The Outer Profiles of Dark Matter Halos as a Probe of Cosmology, Dark Matter and Galaxy Evolution
Susmita Adhikari, Stanford University
The distribution of matter in a dark matter halo contains information about the history of its growth. In this talk I will discuss the recent theoretical developments on how the overall matter distribution and the splashback radius in the outskirts of a cluster can be used to test the nature of gravity and dark matter models. I will also talk about the recent observational developments in measuring the distribution of galaxies and matter around the splashback radius in massive galaxy clusters in DES, SPT and ACT and what we learn about the evolution of galaxies from it. - October 11, 2019 | 12:00 PM | ERC 401 | Friday noon seminar
Better Neutrinoless Double Beta Decay through Biochemistry
Ben J P Jones, University of Texas at Arlington
The goal of future neutrinoless double beta decay experiments is to establish whether neutrino is its own antiparticle, by searching for an ultra-rare decay process with a half life that may be more than 10^27 years. Such a discovery would have major implications for cosmology and particle physics, but requires ton-scale detectors with backgrounds below 1 count per ton per year. This is a formidable technological challenge that has prompted consideration of unconventional solutions. I will discuss an approach being developed within the NEXT collaboration: high pressure xenon gas time projection chambers augmented single molecule fluorescent imaging-based barium tagging. This combines techniques from the fields of biochemistry, super-resolution microscopy, organic synthesis and nuclear physics, possibly enabling the first effectively background-free, ton-scale neutrinoless double beta decay technology. - October 18, 2019 | 12:00 PM | ERC 401 | Friday noon seminar
How Do You Form a Binary Black Hole?
Carl Rodriguez, Harvard
When an isolated binary black hole merges in the field of a galaxy, its gravitational-wave story is complete. But when black holes merge in a dense star cluster, their merger products can remain in the cluster, where they continue to participate in dynamical encounters, form binaries, and
potentially merge again. In this talk I will describe the production of
repeated mergers in globular clusters, and how the rate of mergers depends on the initial properties (e.g. spin) of black holes formed from stars. I will show how these "second-generation" black holes differ from black holes formed from stellar collapse, and how Advanced LIGO and Virgo can already distinguish these unique astrophysical populations. - October 25, 2019 | 12:00 PM | ERC 576 | Friday noon seminar
Simulating Galaxy Formation in the Early Universe
Sarah Wellons, Northwestern University
As techniques have improved over the last decade, observations have peered deep into the Universe's history and begun to glimpse galaxies which formed in the first few billion years after the Big Bang. Evidence is mounting that galaxies in the early Universe appear and behave very differently from those nearby - for example, the most massive galaxies are extremely compact, and star-forming disks appear to have strange clumpy morphologies. In this talk, I will discuss galaxy formation at z > 2 from a theoretical perspective, presenting results drawn from both Illustris, a large-volume cosmological simulation (which allows us to compare and predict the statistical properties of galaxy populations), and FIRE high-resolution zoom-in simulations (which allow us to drill down on the physics governing individual systems). I will focus in particular on massive compact galaxies, whose varied formation and evolution present a case study on how galaxy populations evolve over time, and on massive disks, whose rapid rotation can tell us about the distribution of baryonic and dark matter in the earliest galaxies. - November 1, 2019 | 12:00 PM | ERC 576 | Friday noon seminar
Self-Interacting Dark Matter
Yu Hai-Bo, University of California, Riverside
Astrophysical observations spanning dwarf galaxies to galaxy clusters indicate that dark matter densities in their central regions are much more diverse than predicted in the prevailing cold dark matter theory. In this talk, I will show that self-interacting dark matter can provide a unified solution to a number of long-standing puzzles in astronomy and astrophysics, including the diverse rotation curves of spiral galaxies, dark matter distributions in Milky-Way satellite galaxies and density cores in galaxy clusters. - November 8, 2019 | 12:00 PM | ERC 401 | Friday noon seminar
Lensing of the CMB and intensity maps: analogy with galaxy lensing and application to foreground cleaning
Emmanuel S Schaan, Lawrence Berkeley National Laboratory
Current CMB lensing measurements rely heavily on temperature (vs polarization). In this regime, extragalactic foregrounds produce significant lensing biases, which are difficult to control with frequency cleaning or masking. After reviewing existing methods, I will clarify the analogy between galaxy lensing and CMB lensing, and use it to split the standard CMB lensing quadratic estimator into shear-only and magnification-only estimators. The different symmetries of the lensed CMB and extragalactic foregrounds make the shear-only estimator robust to this contamination, as I will demonstrate with realistic simulations. I will generalize these estimators to optimal "multipole" estimators, and show one avenue to generalize them to polarization and maximum likelihood lensing methods. Furthermore, extragalactic foregrounds are emitted at cosmological distances, and are therefore themselves lensed. This causes an additional bias to CMB lensing, but is also potentially a new signal. I will propose a method to measure the lensing of foregrounds like the cosmic infrared background, and of intensity maps like the 21cm. - November 15, 2019 | 12:00 PM | ERC 401 | Friday noon seminar
Binary evolution: a multi-messenger, multi-band puzzle
Katelyn Breivik, Canadian Institute for Theoretical Astrophysics
Recent observations of binary black hole and binary neutron star mergers have ignited interest in the formation and evolution of compact-object binary systems. However, by the time a compact-object binary merges and produces gravitational-wave/electromagnetic signals we can observe, much of the evolutionary history of the stellar progenitors is washed away. By combining binary population synthesis simulations with observations, we can constrain the uncertain processes that govern the evolution of binary stars from zero age main sequence through to compact object formation and merger. In this talk I will introduce a community developed population synthesis code: COSMIC and highlight recent work on how we can combine binary population simulations with future observations from the Laser Interferometer Space Antenna (LISA) and Gaia to constrain the formation of compact-object binaries. - November 22, 2019 | 12:00 PM | ERC 401 | Friday noon seminar
Single electron charge resolution with the first prototypes of DAMIC-M skipper CCD's
Pitam Mitra, University of Washington
The DAMIC (Dark Matter In CCDs) experiment has pioneered the detection of nuclear and electronic recoils in the silicon bulk of charge coupled devices (CCDs) to search for dark matter particles. A 40g detector is presently being operated at the SNOLAB underground laboratory. The DAMIC-M experiment---to be installed at the Laboratoire Souterrain de Modane in France---is the successor to DAMIC at SNOLAB. This kg-size detector will feature a novel CCD readout with unprecedented single electron-hole pair resolution. First prototypes of DAMIC-M CCDs were packaged and characterized. A resolution of 0.07 electrons was achieved. In this talk, I will present the packaging procedure, the implementation of the CCD readout sequence, and the characterization of the first CCDs. I will also summarize the experimental design and science goals of the DAMIC-M experiment. - December 6, 2019 | 12:00 PM | ERC 401 | Friday noon seminar
FRB Astrophysics in the Era of CHIME
Emmanuel Fonseca, McGill University
Fast radio bursts (FRBs) are millisecond-duration signals of extragalactic origin; the nature of the FRB source is largely unknown and the subject of active debate. The discovery of repeating sources has further amplified their mysterious nature since non-cataclysmic models must be able to explain the diverse observed properties of the FRB phenomenon. Current projections indicate that thousands of FRBs occur across the sky per day, though most premier facilities are not suited for detecting many FRBs over a large sky area and in real time, thus making large-sample analyses difficult until now. In this talk, I will discuss the autonomous FRB detection instrument built for the Canadian Hydrogen Intensity Mapping Experiment (CHIME). I will highlight recent science results from the CHIME/FRB project and share prospects for localizing repeating FRB sources found by CHIME/FRB to their host galaxies, the latter of which enables multi-wavelength studies of the sources and their environment.
OPEN GROUP SEMINARS - October 1, 2019 | 11:00 AM | ERC 401 | Open Group seminar
CMB Lensing Tomography at 0<z<2 with Galaxies from the unWISE Catalog
Alex Krolewski, Berkeley
CMB lensing tomography has the potential to map the amplitude and growth of structure over cosmic time, provide some of the most stringent tests of gravity, and break important degeneracies between cosmological parameters. I use the unWISE photometric galaxy catalog to create three samples at median redshifts z~0.6, 1.1, and 1.5, and cross-correlate them with the most recent Planck CMB lensing maps. The resulting significance of 58.7 at 300 < ell < 1000 is the highest significance detection to date of CMB lensing cross-correlation. The redshift distribution of the two-band unWISE galaxies is a major source of systematic error. I primarily use cross-correlations with BOSS galaxies and quasars and eBOSS quasars to measure the redshift distribution, supplemented with cross-matching to deep COSMOS photometric redshifts. I demonstrate how to propagate the uncertainty in the redshift distribution to the modeling of the signal, and perform a number of null tests. Finally, I discuss the cosmological implications of this measurement and lessons learned for CMB lensing cross-correlations with future photometric surveys such as LSST. - October 10, 2019 | 1:30 PM | ERC 445 | Open Group seminar
Probing LSS with Large Galaxy Surveys: Systematics and Estimators
Humna Awan, Rutgers University
Studying cosmology with large galaxy surveys requires an unprecedented understandingand mitigation of systematics -- a challenge that can be addressed on two fronts: quantification of the impacts of systematics, and new tools to mitigate them. Addressing the first, I will discuss work on the artifacts induced by the observing strategy for the Large Synoptic Survey Telescope (LSST) and present large dithers as an effective mechanism to mitigate the induced artifacts (Awan et al. 2016, ApJ, 829, 50) -- a result that has now been adopted for the LSST observing strategy. I will also quantify the impacts of Milky Way dust on Large-Scale Structure (LSS) studies and the resulting cosmological parameter estimation. As for new tools, I will present a galaxy angular correlation function estimator that corrects for sample contamination arising from photometric-redshift estimation (Awan & Gawiser, 2019, submitted to ApJ); our framework allows for optimization of the estimator to improve the precision of cosmological parameter estimation. While these techniques are motivated by preparations for LSST, they are applicable to DES, DESI, HETDEX, Euclid, and WFIRST. - October 15, 2019 | 1:00 PM | ERC 419 | Open Group seminar
The view from the boundary: Bootstrapping inflationary correlators
Austin Joyce, Columbia University
I will describe the construction of slow-roll inflationary correlation functions directly from symmetry principles. From this perspective, the imprints of massive particles present during inflation can be parameterized in a systematic way, utilizing tools from conformal field theory. These techniques can also be applied to spinning particles (like the graviton) and help shed light on the analytic structure of cosmological correlators. - October 17, 2019 | 1:30 PM | ERC 445 | Open Group seminar
Target Neutrino Mass Precision for Determining the Neutrino Hierarchy
Constance Mahony, University College London
The ordering of the neutrino mass eigenstates, the neutrino hierarchy, is a key question in neutrino physics. Recently, many works have performed a joint analysis of neutrino oscillation and cosmological data to determine the neutrino hierarchy. They have found a range of odds in favour of the normal hierarchy; however these results have been driven by differing approaches to incorporating prior knowledge about neutrinos. In this talk I will present a hierarchy-agnostic prior, which guarantees that the final odds are driven by the data, and show that the hierarchy cannot currently be determined. The determination of the hierarchy is limited by the neutrino mass scale $Sigma_{
u}$ measurement. I will therefore present a target precision $sigma(Sigma_{
u})$ for conclusively establishing the normal hierarchy with future data. - November 1, 2019 | 3:00 PM | ERC 419 | Open Group seminar
Galaxy ecosystems and the Cosmic Web
Joseph N. Burchett, UC - Santa Cruz
Host: Nickolay Gnedin
Forming new generations of stars in galaxies critically depends on both feeding and feedback processes that fuel and regulate their gas supply. The circumgalactic medium (CGM) serves as both a gas reservoir and mediator of all interactions between galaxies and their environments. Not only do matter and energy transport in or out of a galaxy occur in the CGM, but larger scale effects such as ram-pressure or tidal stripping in groups and clusters must first impact the CGM. On even larger scales, the total gas budget that must feed these reservoirs is distributed among the filaments, sheets, nodes, and voids of the Cosmic Web. I will present observations at each of these scales demonstrating 1) feedback caught in the act via a 40 kpc scale outflow mapped in emission, 2) the suppression of cold halo gas reservoirs in groups and clusters, and 3) how gas in the intergalactic medium is distributed with respect to the Cosmic Web traced by galaxies and is shock-heated in the centers of filaments. Toward this final point, I will present a new Cosmic Web reconstruction method inspired by the /Physarum polycephalum/ slime mold, which recovers the environmental dependencies of galaxy properties with high fidelity. - November 15, 2019 | 3:00 PM | ERC 419 | Open Group seminar
Next Generation N-body Cosmology with Abacus on the Summit Supercomputer
Nina Maksimova, Harvard
Abacus is a high-performance, high-accuracy N-body code capable of solving supercomputer-sized problems on a single node at a fraction of the node-hours of other codes, while simultaneously retaining significantly higher accuracy. I will talk about our current work on producing a massive suite of N-body simulations on the Summit supercomputer, which we will make publicly available in 2020. - November 25, 2019 | 3:30 PM | ERC 401 | Open Group seminar
Fun with Intrinsic Alignments: Exploring Beyond LCDM with Cosmological Surveys
Jonathan Blazek, EPFL
Several current and future surveys, including DES, KiDS, and LSST, utilize weak lensing and galaxy clustering observables to constrain the underlying cosmological model. Astrophysical effects can contaminate these observations with systematic uncertainties. I will discuss one of these effects, the intrinsic alignments (IA) of galaxies. Mitigating IA in standard cosmological analyses is an important priority for future projects. However, I will focus on novel applications of IA to probe other physics, ranging from galaxy formation to violations of the equivalence principle in the dark sector.
ASTRONOMY SPECIAL SEMINARS - September 30, 2019 | 3:00 PM | ERC 576 | Special Seminar
Relativistic outflows in Neutron star mergers
Ore Gottlieb, University of Tel Aviv
Relativistic outflows in Neutron star mergers Following a double Neutron star merger a relativistic jet propagates and interacts with the outflowing ejecta that surrounds the merger. As a result, matter is pushed around the jet to form a hot cocoon which applies pressure on the jet and potentially collimates it. After the jet breaks out from the merger ejecta, the cocoon expands and emits radiation over large angles throughout the entire electromagnetic spectrum. I will first discuss the evolution of the jet-cocoon system inside the ejecta and its effect on the morphology and emission from the outflow. Then I will present the different emission mechanisms of the jet+cocoon system, from the first seconds to years later, and how they compare with the set of observables in GW170817. I will conclude with what we expect from future events and what the jet-cocoon emission can tell us about Neutron star mergers and beyond.
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Overview