MATs (Monday Afternoon Talks) 4/3/2023 – Speakers: Haowen Zhang (Arizona) And Erica Thygesen (MSU)

Monday April 3, 2023 3:00 pm


MATs (Monday Afternoon Talks)

3:00pm   Haowen Zhang, University of Arizona

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 from 0 < z < 10 and SMBH observables from 0 < z < 6.5. The model includes full treatment of observational systematics (e.g., AGN obscuration and errors in stellar masses). From these data, TRINITY infers the average SMBH mass, SMBH accretion rate, merger rate, and Eddington ratio distribution as functions of halo mass, galaxy stellar mass, and redshift. Key findings include: 1) the normalization and the slope of the SMBH mass–bulge mass relation increases mildly from z = 0 to z = 10; 2) The apparent overmassive SMBHs at z~6 can be explained by selection bias in flux limited surveys. Trinity also predicts the quasar luminosity functions as a function of host galaxy mass and redshift, which will enable more accurate high-z galaxy property measurements in the JWST era.

3:30pm   Erica Thygesen, Michigan Sate University

The K2 & TESS Synergy: Combining NASA’s Planet Hunters

In the era of JWST, we are poised to study the atmospheres of transiting exoplanets with unprecedented detail – but only if we know when to look. K2 discovered hundreds of such exoplanets that we can observe with current and future missions like JWST and ARIEL, but most K2 planets have uncertainties on future transit times within the next decade of greater than four hours, making observations impractical for many facilities. Fortunately, NASA’s TESS mission has reobserved most K2 planets, providing the opportunity to significantly improve the ephemerides of these systems. The K2 and TESS Synergy is a dedicated effort to create a public catalog of updated K2 planet ephemerides and self-consistent parameters. Combining observations from K2 and TESS with archival radial velocities, we reduce uncertainties on future transit times from hours to minutes. I will present our current results and discuss our plans to reanalyze all ~250 K2 systems observed by TESS during its extended missions.

Host: Josh Borrow


  • Haowen Zhang, University of Arizona
  • Erica Thygesen, Michigan State University

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