[seminar] Astro Journal Club on November 8th (Wednesday, 3 p.m.)

[Lana Ceraj]

Dear all,

on our next AJC next Wednesday (Nov 8th) at 3 p.m. (sharp) in the seminar room F-201 of the Physics Department we are going to talk about quenching in early type galaxies.

Presenter: Ivan Delvecchio, dr. sc.

Title of paper: The surprisingly large dust and gas content of quiescent galaxies art z>1.4

Authors: T. Gobar et al. (2017)

Abstract: 
Early type galaxies (ETG) contain most of the stars present in the local Universe and, above a stellar mass of ~5e10 Msun, vastly outnumber spiral galaxies like the Milky Way. These massive spheroidal galaxies have, in the present day, very little gas or dust, and their stellar populations have been evolving passively for over 10 billion years. The physical mechanisms that led to the termination of star formation in these galaxies and depletion of their interstellar medium remain largely conjectural. In particular, there are currently no direct measurements of the amount of residual gas that might be still present in newly quiescent spheroids at high redshift. Here we show that quiescent ETGs at z~1.8, close to their epoch of quenching, contained 2-3 orders of magnitude more dust at fixed stellar mass than local ETGs. This implies the presence of substantial amounts of gas (5-10%), which was however consumed less efficiently than in more active galaxies, probably due to their spheroidal morphology, and consistently with our simulations. This lower star formation efficiency, and an extended hot gas halo possibly maintained by persistent feedback from an active galactic nucleus (AGN), combine to keep ETGs mostly passive throughout cosmic time. 

Link to paper: https://arxiv.org/abs/1703.02207


If you’d like to present a paper from the field of astrophysics, please contact me via this email (lceraj at phy.hr <mailto:lceraj at phy.hr>). All slots but the one on November 15th are still free.


Information about upcoming AJC seminars and links to previous AJC presentations and corresponding papers you can find at a webpage: https://lanaceraj.wixsite.com/ajc-main 
If you have comments on a design and purpose of the AJC webpage and suggestions how to improve it, please talk to me after the seminar next Wednesday.

See you all on Wednesday.

Cheers,
Lana
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