Event Type: Monday Afternoon Science Talks

Rebecca Surman & Victoria DiTomasso

November 26, 2025

Rebecca Surman, University of Notre Dame Victoria DiTomasso, Harvard CfA

Yixian Chen & Zachary Stone

November 26, 2025

Yixian Chen, UC Santa Cruz Unorthodox planet-disk interaction: Eccentricity, Turbulence and Winds The classical circumplanetary disk (CPD) pattern is prograde – in other words, aligned with the Protoplanetary disk. Using 3D global hydrodynamic simulations, we show that when planet eccentricity is large enough, the CPD can become retrograde due to impact velocity relative to the

Richard Pan & Pipit Triani

November 26, 2025

Richard Pan, Tufts University Pipit Triani, Harvard CfA  

Wata Chanita Tubthong & Weizhe Liu

November 26, 2025

Wata Chanita Tubthong (Tufts University) Small circumbinary planets are truly rarer than small single-star planets All circumbinary planets (CBPs) confirmed up-to-date are gas giants. No circumbinary super Earth has been discovered, despite the super Earths making up ~80% of the planet population around single stars. This is owing to the inherently biased nature of the

Sabrina Berger and Yang Sun

August 26, 2025

Sabrina Berger (The University of Melbourne) Title: Simulations Meet JWST to Understand AGN at Cosmic Dawn Abstract: The James Webb Space Telescope (JWST) is transforming our understanding of active galactic nuclei (AGN) in the early Universe. For the first time, astronomers have detected and characterized galaxies hosting luminous quasars at z > 6. JWST has

Scott Lucchini

August 26, 2025

Scott Lucchini, Harvard CfA Title: The Circumgalactic Medium at 200 pc Abstract: The circumgalactic medium (CGM) plays a crucial role in the baryon cycle by mediating all of the gas flows in and out of the galaxy. However, simulating this region is difficult due to its immense volume and low densities. Fixed spatial resolution is

Myles Sherman & Isabel Sands

August 14, 2025

Myles Sherman (Caltech) Searching for Long-Period Radio Transients with the DSA-110 In this talk, I will describe the design and commissioning tests for the DSA-110 Not-So-Fast Radio Burst (NSFRB) search pipeline, a 1.4 GHz image-plane single-pulse search sensitive to 134 ms-160.8 s radio bursts. Extending the pulse width range of the DSA-110 Fast Radio Burst

Alexa Gordon & Jacob (Jake) Nibauer

August 14, 2025

Alexa Gordon (Northwestern University) Revealing the Progenitor(s) of Fast Radio Bursts through their Environments Abstract: Fast radio bursts (FRBs) are a new class of highly energetic, extragalactic transients. Despite thousands of FRBs detected to date, many fundamental questions remain, including their progenitor(s) and emission mechanism(s). The ability to localize FRBs to sub-arcsecond precision–pinpointing them to

Peter Scherbak & Saugata Barat

August 14, 2025

Peter Scherbak (Caltech) Title: Rapid Binary Mass Transfer: Circumbinary Outflows and Angular Momentum Losses across Mass Transfer Rates Abstract: High rates of stable mass transfer (MT) occur in some binary star systems, producing luminous transients and driving circumbinary outflows. We perform hydrodynamical simulations of a donor star transferring mass to a point-mass accretor across a range of

Philippe Yao & Yonadav (Barry) Ginat

August 14, 2025

Philippe Yao: Theoretical Models for Repeating Nuclear Transients: Stellar Orbits, Disk Encounters & Mass Transfer Barry Ginat: The Small-Scale Limit of the Cold-Dark-Matter Power-Spectrum

Ajay Gill & Shaunak Mondak

August 14, 2025

Ajay Gill (MIT AeroAstro) Title: A study of galaxy clusters and filaments with the Sunyaev–Zeldovich effect using multifrequency cosmic microwave background observations Abstract: Galaxy clusters are the largest gravitationally bound objects in the universe. Their study probes the evolution of large-scale structure in the universe. I will discuss a new methodology to study the thermal

Karthik Yadavalli & Zeyuan Xuan

August 14, 2025

Karthik Yadavalli (Harvard/CfA) Title: Radiative Transfer Modeling Supernovae to Understand Progenitor Physics Abstract: The specifics of the final-stage evolution and death of a massive star are not perfectly known. In particular, how the population of stars that lead to type Ib and Ic SNe (SNe Ib/c) experience core-collapse and ultimately explode as supernovae is so

Junehyong Jeon & Vedant Chandra

August 14, 2025

Junehyong Jeon: Formation and Evolution of Supermassive Black Holes in the Early Universe Vedant Chandra: Tales from the Milky Way’s Distant Horizon

Chun Huang & Aimee Schechter

August 14, 2025

Chun Huang (Washington University in St. Louis) Linking Multiwavelength Pulsar Emission to Super-Dense Physics inside neutron star The utilization of Pulse Profile modeling techniques could simultaneously provide measurements for Neutron star Mass Radius and offer insights into their hotspot distribution. Presently, these methodologies rely on meta models of the equation of state (EOS) and employ

Yilun Ma & Jamie Lin

April 26, 2025

Talk 1: Yilun Ma, 3:00pm – 3:30pm Searching for little red dots across redshifts Little red dots (LRD) are a population of red, compact, broad-line objects discovered by JWST at 5<z<8. They show a characteristic V-shaped SED, where a blue UV continuum is followed by a steep red rise in optical, and they are otherwise not

Sunil Simha

March 21, 2025

Talk: Sunil Simha, 3:00pm – 3:30pm Cosmic accountancy: Baryon budgeting using FRB dispersion measures Fast Radio Bursts (FRBs) are being detected and precisely localized (~<1’’) at an accelerating pace due to the efforts of several FRB experiments worldwide. Chief among these is the CHIME telescope and its outriggers, which are well on their way to localizing

Dave Clements

March 21, 2025

Talk: Dave Clements, 3:00pm – 3:30pm The deepest Herschel-SPIRE Field We present the first results from the deepest far-IR observations ever made. These come from the Herschel-SPIRE dark field, a region observed multiple times over the entire course of the Herschel mission for calibration and instrument health purposes. Our final images combine 141 separate observations

Saiyang Zhang & Lizhong Zhang

March 5, 2025

Talk 1: Salyang Zhang, 3:00pm – 3:30pm The imprint of primordial black holes over cosmic history My presentation will discuss the role of Primordial Black Holes (PBHs) as one of DM components throughout cosmic history. I will specifically focus on PBH candidates in the solar mass range of approximately 10-100 $M_{\odot}$ and massive PBHs of $10^6

Christopher Lindsay

March 5, 2025

Talk: Christopher Lindsay, 3:00pm – 3:30pm Stellar astrophysics and galactic archaeology with asteroseismology The analysis of stellar oscillations, known as asteroseismology, has enabled detailed studies of the interior structures of stars, particularly subgiants and red giants. Since many areas of astrophysics rely on stellar modeling, asteroseismology provides a vital tool for improving our understanding of how

Marie Lau

March 2, 2025

Talk : Marie Lau, 3:00pm – 3:30pm Probing Quasar/galaxy evolution, feeding, and feedback: Extremely Red Quasars (ERQs) and the Quasar-Associated Inflows Legacy Survey (QUAILS) My research focuses on understanding the evolution, feeding, and feedback processes in quasar-host galaxies, particularly through extremely red quasars (ERQs) and quasar-associated absorption lines. First, I study ERQs at cosmic-noon redshifts. Using

Jesse Han

February 28, 2025

Talk : Jesse Han, 3:00pm – 3:30pm Hypervelocity Stars Trace a Supermassive Black Hole in the Large Magellanic Cloud Hypervelocity stars (HVSs) are produced by the Hills mechanism when a stellar binary is disrupted by a supermassive black hole (SMBH). The HVS Survey detected 21 unbound B-type main-sequence stars in the Milky Way’s outer halo that

Tiger Hsiao

January 24, 2025

Talk 1: Tiger Hsiao, 3:00pm – 3:30pm First star clusters observed in the early universe with JWST and gravitational lensing Understanding when, how, and why the first generation of stars and galaxies formed is crucial for revealing the early chapters of cosmic history. To reveal the first chapter of cosmic history and understand our cosmic

Grant Donnelly & Andra Stroe

January 24, 2025

Talk 1: Grant Donnelly, 3:00pm – 3:30pm Touched by fire: insights from PAHs in active galaxies The space between the stars in galaxies is sprinkled with particles of condensed matter collectively referred to as “dust”. Absorbing large amounts of starlight and consequently glowing in the infrared, dust is a critical component of interstellar radiative transfer,

Ben Lakeland

January 24, 2025

Talk 1: Ben Lakeland, 3:00pm – 3:30pm Using the sun to find earth twins Radial-velocity (RV) spectroscopy is a vital tool in exoplanet science, both as an independent detection method and as follow-up characterization for transiting exoplanets. State-of-the-art RV spectrographs have the instrumental sensitivity to detect sub-meter-per-second variations necessary to detect small exoplanets. Despite this,

Charlie Mpetha

January 21, 2025

Talk: Charlie Mpetha, 3:00pm – 3:30pm The infall region of galaxy clusters as a complementary probe to cluster abundance Galaxy cluster abundance measurements provide a classic test of cosmology. However, they exhibit a strong degeneracy between the amplitude of density fluctuations σ8, and the matter density Ωm, as do other similar low-redshift tests such as

Minori Shikauchi

October 1, 2024

Talk: Minori Shikauchi, 3:00pm – 3:30pm A blind search for gamma-ray burst afterglows with CHIME Short gamma-ray bursts (sGRBs) are energetic and explosive events in the Universe.  The coincident detection of GRB 170817A and a gravitational wave (GW) from a binary neutron star (BNS) merger raises questions about the conditions in which BNS mergers cause

Shreya Anand & Dhayaa Anbajagane

October 1, 2024

Talk 1: Shreya Anand, 3:00pm – 3:30pm Testing whether Collapsars Synthesize r-process elements A rare sub-class of stripped envelope massive-star explosions, dubbed broad-lined Ic supernovae (SNe Ic-BL) have been highlighted as one of the potential sites of r-process nucleosynthesis capable of enriching our solar neighborhood with heavy elements. Here we present the first systematic study

Tom Rose & Congyao Zhang

October 1, 2024

Talk 1: Tom Rose, 3:00pm – 3:30pm Observing AGN fueling via molecular absorption lines Molecular gas plays a significant role in powering AGN. Unfortunately, observing this gas on small spatial scales is difficult because it can normally only be seen en masse through emission lines. I will present observations of molecular gas in several massive

Haowen Zhang & Erica Thygesen

October 1, 2024

Talk 1: Haowen Zhang, 3:00pm – 3:30pm Trinity: self-consistent dark matter halo-galaxy-supermassive black hole connection from z=0-10, and predictions on high-z quasars in the JWST era We present TRINITY, a flexible empirical model that self-consistently infers the statistical connection between dark matter haloes, galaxies, and supermassive black holes (SMBHs). TRINITY is constrained by galaxy observables

Lalitha Sairam & Genevieve Schroeder

October 1, 2024

Talk 1: Lalitha Sairam, 3:00pm – 3:30pm When stars misbehave: the impact of stellar activity on exoplanet research and the need for a public forecast The study of exoplanets has unveiled a diverse array of worlds beyond our solar system. However, the detection and characterization of exoplanets remain challenging due to the magnetic activity of

Xiurui Zhao & Sebastian von Hausegger

October 1, 2024

Talk 1: Xiurui Zhao, 3:00pm – 3:30pm Active galactic nuclei in the NuSTAR era Active galactic nuclei (AGN), which represent the rapidly growing phase of the supermassive black holes (SMBH), radiate across the whole electromagnetic spectrum from radio to Gamma-rays. X-rays, which are seen in most AGN, are an important tool to study the physics

Evan Bauer & Ryan Lau

October 1, 2024

Talk 1: Evan Bauer, 3:00pm – 3:30pm Modeling runaway donor stars to understand supernovae in white dwarf binaries In the quest to understand the physics and astrophysics of how Type Ia supernovae occur, we have recently turned attention toward better understanding the physics of mass transfer and detonation in double white dwarf binary systems. These

Jean Somalwar

October 1, 2024

Talk: Jean Somalwar, 3:00pm – 3:30pm Tidal disruption events in the VLA Sky Survey The ubiquity of supermassive black holes in galactic centers leads to a cornucopia of dramatic phenomena. One of the most spectacular of these occurs when a star ventures near the SMBH and is shredded in a tidal disruption event (TDE). TDEs produce bright,

Cheng-Lin Liao & Ben Zhang

October 1, 2024

Talk 1: Cheng-Lin Liao, 3:00pm – 3:30pm Extending to the brightest end: physical properties of the 870um brightest dusty star-forming galaxies at z~3 Dusty star-forming galaxies (DSFGs), luminous in the infrared, are dust-rich galaxies with intense star formation (SFR~10-1000 Msun/yr) predominantly at cosmic noon (z~1-3). They are crucial for understanding galaxy formation and evolution, as

Will Roper & Alex Gough

September 30, 2024

Talk 1: Will Roper, 3:00pm – 3:30pm Massive compact galaxies in the Epoch of Reionization – this can’t be right…a tale of confusion, surprise, and compact galaxies Massive galaxies in the early universe are thought to be highly compact, an assertion which the first Webb observations have only strengthened. Indeed, in the First Light And

Molly Wolfson & Jubee Sohn

September 30, 2024

Talk 1: Molly Wolfson, 3:00pm – 3:30pm Constraining reionization with the Lyman-a forest flux auto-correlation function Reionization is a major phase change in our universe’s history and understanding this transition remains a major open problem. One measurable signature of reionization is the mean free path of ionizing photons (λmfp) which rapidly evolves at the end

Manas Vishal

September 30, 2024

Talk: Manas Vishal, 3:00pm – 3:30pm A discontinuous Galerkin method for the distributionally-sourced s=0 Teukolsky equation With the detection of first gravitational waves in 2015 by the laser interferometers at Laser Interferometer Gravitational wave Observatories (LIGO) located in Hanford and Livingston that was followed by a Nobel prize, there is an urgent need of more

Jack Neustadt & Jon Zink

September 30, 2024

Talk 1: Jack Neustadt, 3:00pm – 3:30pm Looking beyond the lamppost: a new method of understanding AGN continuum variability The variability of Active Galactic Nuclei (AGNs) has been studied for decades, with the UV/optical continuum observed to stochastically fluctuate at the 10% level over timescales of weeks to months. Fundamentally, this variability should be driven

Adriana Dropulic & Madeleine McKenzie

September 30, 2024

Talk 1: Adriana Dropulic, 3:00pm – 3:30pm StreamGen: morphologies and orbits of semi-analytic satellite galaxies Stellar streams are excellent probes of dark matter halos and their structure. Interestingly, the Milky Way’s stellar streams are significantly more clustered in the inner regions of the Galaxy compared to those in simulations. These simulations are expensive and can

Zhihui Li

September 30, 2024

Talk: Zhihui Li, 3:00pm – 3:30pm Unveiling the multiphase, clumpy structure of the Circumgalactic Medium of High-z galaxies In this talk, I will present our recent progress on constraining the physical properties of the ”cool” (T ~ 104K) phase of the circumgalactic medium (CGM) via modeling Lya emission and low-ionization-state (LIS) metal absorption lines. We developed

Jesse Han & Arpit Arora

September 30, 2024

Talk 1: Jesse Han, 3:00pm – 3:30pm A galactic mystery ‘unwarped’ The outer disk of the Milky Way Galaxy is warped and flared. Several mechanisms have been proposed to explain these phenomena, but none have quantitatively reproduced both features. Recent work has demonstrated that the Galactic stellar halo is tilted with respect to the disk