Astrophysical Fluid Dynamics and Methods Meeting Room: Classroom Please contact James Cho if interested in joining.

Machine Learning Group Meeting Room: Classroom Machine Learning Group Meeting Description: Please email Gabriella Contardo to join if interested in the nuts and bolts of ML x Astrophysics.

Exoplanets Meeting Room: Classroom An initial meeting for CCA astronomers interested in exoplanets. At this meeting, we will discuss what we want from an exoplanets meeting and decide on a schedule going forward.

Cosmology Informal Meeting Room: Classroom Please email Lehman Garrison to join if interested in a detailed project discussion.

Stars and Exoplanets Meeting Room: Classroom Researchers in the NYC area working on the Milky Way, stellar astrophysics, and extra-solar planets gather to discuss projects in progress and scientific issues of mutual interest. This meeting is open.

Gravitational Waves Group Meeting Room: Classroom

SF Lecture: Will Farr Room: Classroom Gerald D. Fischbach Auditorium - 160 Fifth Avenue at 21st Street, 2nd floor Black Hole Bells and Other Exciting Recent Results in Gravitational Wave Astronomy In the last five years, the exciting new field of gravitational wave astronomy has delivered many firsts: the first detection of gravitational waves — from a pair of black holes merging — in 2015; the first detection of gravitational waves from a merging pair of neutron stars — an event which also produced electromagnetic emission that was ultimately observed in various ways by roughly 30 percent of the global astronomical community — in 2017; the first catalog of binary black hole mergers that provided evidence for a maximum stellar-origin black hole mass due to an unusual type of supernova explosion in 2018; the first detection of multiple gravitational wave ‘spectral lines’ from a ‘ringing’ black hole announced in 2019; and many oddities in 2020, including a black hole merger with masses above the stellar-origin limit, a detection of an unusually massive neutron star merger, and a detection of a merger with one object with a mass that is larger than expected for a neutron star but smaller than expected for a black hole. In this lecture, Will M. Farr will discuss some of these exciting results in detail and explain the bright future of this fast-moving new field. Farr earned his B.S. in physics from Caltech and, in 2010, his Ph.D. from MIT. After a CIERA fellowship at Northwestern University, he joined the faculty at the University of Birmingham in 2013. In 2018, he moved to Stony Brook University and the Flatiron Institute’s Center for Computational Astrophysics (CCA). He is currently an associate professor of physics and astronomy at Stony Brook University and the leader of the CCA’s Gravitational Wave Astronomy group. He is a member of the LIGO Scientific Collaboration, an international collaboration of scientists studying gravitational waves detected by the LIGO instruments. Registration is required for this free webinar. Further instructions and access to join the webinar will be sent to all registrants upon sign up.

Compact Objects Group Meeting Room: Classroom

Dynamics Group Meeting Room: Classroom Dynamics Group Meeting Description: Group members meet for workshop projects. Email Kathryn Johnston if you’d like to participate.

Galaxy Formation Group Meeting Room: Classroom Galaxy Formation Group Meeting Description: By Invitation Only. Email rachel somerville if you would like to participate.

Astronomical Data Internal Group Meeting Room: Classroom Astronomical Data Internal Group Meeting Description: Group members meet for workshop projects. Email Hogg if you’d like to participate.

Cosmology X Data Science Group Meeting Room: Classroom Researchers in the NYC area working on understanding the theory and observations of the Universe via both traditional and novel tools in Data Science gather together to i) Discuss a recent/classic paper, ii) give short talks (15 mins) of their recent work, and iii) flash recent updates from their work. Lunch will be served at CCA. Please contact(ccainfo@simonsfoundation.org) at least 24hrs in advance, if you would like to be added to the participant list to attend this meeting. This meeting alternates its location between NYU-Physics and Flatiron-CCA.

CCA Colloquium: Saavik Ford Room: Classroom CCA Colloquium: Saavik Ford Flatiron Institute, 162 5th Ave, 2nd Floor Ingrid Daubechies Auditorium AGN disks have things in them--and those things are important Active Galactic Nuclei (AGN) have usually been modeled and conceptualized solely in terms of their gas content. However, given the existence of Nuclear Star Clusters (NSCs), it is reasonable to expect stars and stellar remnants will also exist in AGN disks. Their presence leads to several important consequences, notably the AGN-driven channel for mergers of compact objects, detectable with ground-based GW observatories like LIGO-Virgo. I will discuss the mechanisms and open questions of the AGN channel, including the successful predictions of the channel to date. In addition, because mergers of binary black holes in AGN disks occur in the presence of gas, there is the possibility of naturally generating detectable EM counterparts to these mergers. I will discuss the public candidate counterpart and future directions for further searches. Finally, the existence of GW-EM sources provides an independent way of measuring the Hubble Constant, H_0. With sufficient numbers of confirmed AGN GW-EM counterparts, BBH may provide the tightest constraints on the measurement of H_0, and can resolve the tension between SNe- and CMB-based measurements.