Astrophysics Seminar: Evan Núñez, CalTech

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Location: 184 Nieuwland Science Hall (View on map )

Looking Inside and Out: Observationally Connecting the Inner Circumgalactic and Ionized Interstellar Medium of z~2-3 Galaxies with KBSS-InCLOSE

Evan Núñez
Graduate Student
CalTech

Connecting galaxy properties (e.g., ionized interstellar medium or ISM, stellar mass) with the physical conditions of the inner circumgalactic medium (CGM) of z~2-3 star-forming galaxies is necessary to understand the evolution of baryons in the galaxy due to the ubiquity of strong galactic outflows and presence of inflowing/recycled gas at this epoch (i.e., galaxy scale baryon cycle). To accomplish this, we spearhead a new survey that builds upon the Keck Baryonic Structure Survey (KBSS) QSO fields, which will characterize the Inner CGM of QSO Line Of Sight Emitting (InCLOSE) Galaxies at z~2-3. KBSS-InCLOSE has found previously undetected galaxies near the KBSS QSOs with the combination of HST imaging and Keck spectroscopy from KCWI, MOSFIRE, and HIRES. I will present an overview of the survey which, at present, has more than 40 galaxies spanning untouched impact parameters (11-100kpc) at this redshift. Then I will showcase the first results from the survey involving an analysis of two QSO fields with galaxies that are associated with high NHI gas. Among other things, we find that these galaxies' CGM contains a significant amount of mass (HI and metal absorption covering hundred of km/s, bright and extended Lya emission), their CGM metallicity and dust extinction is <1/10 that of the ISM suggesting their CGM is not well mixed, and some of the highest metallicity gas in their CGM will escape their gravitational potential hinting that this mass preferentially propagated from their ISM as dense projectiles of undiluted core collapse supernova products instead of diffuse shells.

Hosted by Prof. Kirby