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Journal Club Seminars

Contents

The Journal Club talks take place on Fridays from 12:00 - 1:00pm in SERF 383. Generally pizza and soda are served.

The Journal Club is crafted to be a very informal and friendly environment where graduate students can present talks on any subject of interest to them, be it a recent journal paper, their own research work, or any topic.

Everyone is welcome to attend.

If you are interested in giving a talk, please contact: Jung-Tsung Li

Past journal club talks are listed in the sidebar by year.

Upcoming Journal Club Seminars

FALL 2018


November 23, 2018

NOTE: Journal Club Cancelled Today - Thanksgiving Day Holiday



November 30, 2018

Grace's Title: "Spatially Resolved Metal Loss from M31"
Dr. Laha's Title: "The role of ionized and molecular outflows in quasar evolution"

Grace Telford (12:00-12:30)
Graduate Student
University of Washington
Sibasish Laha (12:30-1:00)
Postdoctoral Scholar
UCSD-CASS

Grace's Abstract: As galaxies evolve, they must enrich and exchange gas with the intergalactic medium, but the mechanisms driving these processes remain poorly understood. In this work, we leverage missing metals as tracers of past gas flows to constrain the history of metal ejection and redistribution in M31. This nearby, roughly L∗ galaxy is a unique case where spatially resolved measurements of the gas-phase and stellar metallicity, dust extinction, and neutral ISM gas content are available, enabling a census of the metal mass present in stars, gas, and dust. We combine spatially resolved star formation histories from the Panchromatic Hubble Andromeda Treasury survey with a model of metal production by Type II SNe, Type Ia SNe, and AGB stars to calculate the history of metal production in M31. We find that 62% of the metals formed in the M31 disk are missing in our fiducial model. For any reasonable modeling choices, the missing metals from M31’s disk far exceed the metal mass that has been detected in M31’s circumgalactic medium. We then use the metal production histories to place constraints on the timing of this metal loss and on the required redistribution of newly produced metals within the disk in the last 1.5 Gyr.

Dr. Laha's Abstract: The reason for cosmic down sizing of quasars is still a big puzzle in astronomy and it is commonly believed that the central active galactic nucleus (AGN) must have played a significant role in quenching itself, in a self-regulatory mechanism popularly termed “AGN feedback” . The AGN feedback also plays a crucial role in black hole and host galaxy coevolution across cosmic time. In this talk I will discuss the nature and impact of pc scale outflows from AGN, detected in X-rays, popularly known as warm absorbers (WAX sample study, Laha et al. 2014, 2016), as well as kpc scale outflows detected in IR and sub-mm, popularly known as Molecular outflows (MOX sample study, Laha et al. 2018). These different types of outflows are believed to be strong contenders for removing gas and dust from the vicinity of the super massive black hole and thereby starving it to death (quenching). However, the exact nature of the interaction of these outflows with that of the host galaxy gas and dust is still highly debated. Although we largely believe that feedback is an important mechanism by which the quenching happens, it brings us to an interesting question: Is there any fundamental difference between the central engines of the local AGN compared to their high redshift counterparts? Are they simply scaled down (lower black hole mass) versions of their higher redshift counterparts, or are different in some other way? I will present results from a sample study of low luminosity quasars (LLQSO study, Laha et al. 2018) in the local Universe to address this issue.