Anahita Alavi (Caltech/IPAC)

Title: Dwarf Galaxies Before the Era of JWST: A Photometric and Spectroscopic Study of Faint Star-forming Galaxies at High Redshifts

Abstract: Dwarf galaxies (M_*/M₀ < 10⁹) are the smallest and least luminous, but most abundant galaxies in the universe. These galaxies are at the forefront of many important questions in galaxy formation theory, yet observationally we are only just beginning to constrain their cosmic abundance and detailed properties, especially at high redshifts. In this talk I will show how combination of our deep UV imaging with WFC3/UVIS camera on board the Hubble Space Telescope and extensive spectroscopy observations with MOSFIRE spectrograph on Keck allowed us to 1- observe these faint galaxies at 1<z<3, which have always been below the detection limits of many surveys, and 2- better understand the formation and evolution of these long-suspected population of galaxies via studying their number density evolution (i.e, luminosity function) , star formation history (i.e., bursty SFH) and dust attenuation . Knowing that early dwarf galaxies at z>6 will be prime targets of the next generation of telescopes including JWST, I will also discuss why we target dwarf galaxies at 1<z<3. This era is a golden cosmic time to not only prepare for the future observations but to investigate some important properties, such as search for escaping Lyman continuum photons, that fundamentally cannot be studied at the JWST targeted redshifts. A key need in all of these studies is deep UV observations which allowed us to identify these faint star-forming galaxies. To wrap up my talk, I will introduce two new large UV surveys with HST, to further explore the high-redshift dwarf galaxies and how they are different than their bright counterparts.