MATs (Monday Afternoon Talks), 11/13/2023 — Speakers: Mahdi (Sum) Qezlou & Bhagya Subrayan

Monday November 13, 2023 3:00 pm

MATs (Monday Afternoon Talks)

3:00pm – 3:30pm, Mahdi (Sum) Qeziou

Cosmology and galaxy evolution with Ly-alpha tomography
Ly-alpha tomography surveys have produced 3D maps of the Lya opacity of the intergalactic medium (IGM) at z ~ 2.5 with Mpc resolution, offering a new window to discover high-redshift large-scale structures like the progenitors of present-day massive galaxy groups and clusters. This presentation explores the complementarity of Ly-alpha tomography with conventional galaxy surveys. In the largest IGM map to date, the Lyman-α Tomographic IMACS Survey (LATIS), we detect both previously known galaxy protoclusters and a novel population that was missed by galaxy spectroscopic surveys. I also present our independent constraints on the stellar vs. halo mass relation from LATIS tomography. Additionally, I’ll discuss our recent work demonstrating synergies between these tomographic maps and the upcoming line intensity map (LIM) experiments at cosmic noon. This cross-correlation allows one to detect emission from the faintest galaxies, enabling unbiased cosmological and galaxy evolution studies. Throughout the presentation, I will share our progress to date and the promising prospects for the future, covering both the modeling of these new mapping techniques using the largest cosmological hydrodynamic simulations, which is required to fully realize the potential of these techniques, alongside the latest observations in this emerging field.

3:30pm – 4:00pm, Bhagya Subrayan

Maximizing Scientific Return from All Sky Surveys with Time-Critical Inferencing: The “Scary Barbie” story
The Legacy Survey of Space and Time (LSST) by the Rubin Observatory, set to begin operations in 2025, will revolutionize time domain astrophysics by discovering several millions of transients over its planned time, bringing in a new era of “big data” to time domain astrophysics. LSST ’ s transformative capabilities to advance our understanding of the Universe comes with the alarming realization that its grand scope introduces imminent big data challenges. In my talk, I will discuss our latest research in developing automated systems to identify, prioritize and design strategies to follow-up transients from all sky surveys. I will focus on the capability of real-time characterization of transients to make scientifically driven predictions that can efficiently design follow-up strategies. Additionally, I will discuss the utility of such automated systems to detect anomalies from all-sky surveys, with AT 2021lwx aka “Scary Barbie” as an example. AT 2021lwx is one of the most energetic, luminous and long-duration transient ever observed, most likely an extreme tidal disruption candidate event by supermassive black hole (SMBH) at play. Intriguingly, no host galaxy associated with the theorized SMBH has been detected yet at the location of AT 2021lwx, which makes it puzzling.

Hosts: Minghao Yue, Daniele Michilli


  • Mahdi (Sum) Qeziou, UCR & Carnegie
  • Bhagya Subrayan, Purdue University