Contributed

Blackboard talk done for the 2023 “Building a physical understanding of galaxy evolution with data-driven astronomy” KITP workshop https://datadrivengalaxyevolution.github.io/.

The COSMOS field has proved to be one of the cornerstone surveys in extragalactic astronomy. We have built a new photometric redshift catalog COSMOS2020 from the latest ultra-deep imaging from Subaru, VISTA, and Spitzer. We measure 1M sources across the 2 deg$^2$ field using both apertures and profile-fitting photometry, pairing each with two SED fitting codes to derive four sets of precise photometric redshifts. We then measure the form and evolution the Galaxy Stellar Mass Function from 0.2 < z < 7.5 to reveal a strikingly constant rate of mass assembly stretching back into the Epoch of Reionization. We also find new samples of ultra-luminous galaxies at z>7.5 which form the most robust constraints on the UV Luminosity Function at such early times, confirming an excess of luminous sources. Are we witnessing a stage before feedback has suppressed their growth? Such a scenario challenges galaxy formation theory. We will have our answer soon; five of these luminous z~9 galaxies will be followed up with spatially resolved spectroscopy in the Cycle 1 JWST NIRSpec program BEASTS (PI:John R. Weaver). I delve into the details of the PSF fitting and the cosmic variance analysis.

Talk given as part of DAWN weekly cake talk, while the project was still in development phase

Exoplanetary radii is the most commonly measured property of exoplanets, and thus our understanding of how to interpret any measured radius is crucial to the field. Atmospheric existence is often inferred from radius and mass observations, but this is based on the assumption that the interior of planets do not maintain most of the gravitational energy from their collapse. Recently, there have been doubts about this assumption. This project aims to investigate the potential consequences of planets retaining most of the energy from their collapse. Assuming the Murnaghan EOS, we find that stable rocky planets that maintain some of their gravitational energy can have sizeable radius increases, as much as 21% for a planet of 10 M⊕. Furthermore, limits on the amount of energy that can be maintained by a planet will be discussed.