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15529
Seminars

Astrophysics & Space Sciences seminar with Richard Feder-Staehle and Lindsey Gordon

Richard Feder-Staehle from UC Berkeley / LBNL and Lindsey Gordon from UMN (Hosted by Tansu Daylan) will be presenting the Astrophysics & Space Sciences seminar on "From Pixels to Primordial Non-Gaussianity and Beyond: Mission Status and Science with the SPHEREx All-Sky Survey" and "AGN Jets in Complex Cluster Environments", respectively.

From Pixels to Primordial Non-Gaussianity and Beyond: Mission Status and Science with the SPHEREx All-Sky Survey with Richard Feder-Staehle

Modern astronomical surveys using imaging and spectroscopy have dramatically improved our understanding of large-scale structure formation and astrophysics over cosmic history. SPHEREx, NASA’s most recent MIDEX mission, began survey operations on May 1st, 2025 and will deliver the first all-sky, low-resolution spectroscopic survey in the near-infrared spanning 0.75 - 5.0 um, enabling novel science investigations in inflationary cosmology, galaxy formation/evolution, Galactic ices, and more. In this talk, I will introduce SPHEREx and describe the science data modeling currently being pursued to produce the largest galaxy redshift survey (by volume) to date. After highlighting science opportunities and work ahead, I will take a step back and discuss the more general challenges of robust source detection and photometry, which underpin the success of nearly all downstream science cases. In this portion of the talk I will describe recent developments in probabilistic cataloging (PCAT) – a Bayesian, transdimensional, forward modeling framework designed for improved source detection and deblending – and, as time permits, comment on prospects for SPHEREx and other modern surveys.

AGN Jets in Complex Cluster Environments with Lindsey Gordon

AGN jets are the powerful magnetized plasma outflows from the central supermassive black holes of galaxies. Jets are a key component in the feedback cycle of clusters, reheating gas to prevent the massive cooling rates and star formation that is expected but not observed in cluster centers. Cosmological simulations typically implement AGN feedback using a generalized prescriptive model, which produces imperfect galaxy and gas populations. In this work, we model the jets from galaxy to cluster scale to study in detail their feedback on the surrounding intracluster medium (ICM) and the ICM's feedback on the jet's morphology. We consider a wide parameter space of gas turbulence in the ICM and the role of hierarchical galaxy cluster mergers in the gas dynamics. The presence of background turbulence produces quantifiably shorter, smaller jets, with high conversion rates of injected magnetic energy into thermal.
 

Sponsored by the McDonnell Center for the Space Sciences.