Calendar

Oct
13
Fri
PDS Atmospheres Node meeting
Oct 13 @ 10:30 am – 11:30 am
Colloquium: Kyoung-Soo Lee (Host: Moire Prescott)
Oct 13 @ 3:15 pm – 4:15 pm
Colloquium: Kyoung-Soo Lee (Host: Moire Prescott) @ BX102

Colloquium Title

Kyoung-Soo Lee, Purdue University

Abstract text

Oct
16
Mon
Pizza Lunch: Ken Naiff
Oct 16 @ 12:30 pm – 1:30 pm
Pizza Lunch: Ken Naiff @ AY 119

Dark Sky Images

Ken Naiff

Ken, an retired engineer, is a highly technically skilled and artistic
astrophotographer.  He will be sharing some of his work and elaborating on
the technical methods and processing techniques he applies to obtain his
unique and enhanced images.  You can see Ken’s work at:

https://darkskyimagesbyken.com/products

 

Oct
20
Fri
Planetary Group meeting
Oct 20 @ 10:30 am – 11:30 am
Colloquium: Benjamin Oppenheimer (Host: Kristian Finlator)
Oct 20 @ 3:15 pm – 4:15 pm
Colloquium: Benjamin Oppenheimer (Host: Kristian Finlator) @ BX102

Breaking the Self-Similarity of Galaxy Formation: A Circumgalactic Medium Perspective

Benjamin Oppenheimer, University of Colorado Boulder

If you could see a dark matter halo directly without knowing the scale, you probably could not distinguish a Milky Way halo from a cluster-sized halo.  However, if you look at the galaxies, you would likely see a dominant spiral galaxy in the former and a many quenched and quenching galaxies in the latter.  The study of galaxy formation aims to understand how very different galaxies form in dark matter halos of different masses.  I will argue for the importance of understanding the gaseous baryons in this context.  In contrast to the hot intracluster medium detected in emission in clusters, the circumgalactic medium (CGM) has to be probed by absorption lines toward background quasars and tells a vastly different and complicated story.  I will demonstrate, with the aid of hydrodynamic simulations, how the CGM is multi-phase (with cool ~10^4 K clouds embedded in a hot, ambient medium), plus how non-equilibrium ionization processes altering the heavy element ions we probe in spectra.  The next frontiers in the CGM require understanding the dynamics encoded not only in absorption line spectra of the UV, but in the X-ray via emission and absorption.

 

 

Oct
23
Mon
Pizza Lunch: Kristian Finlator
Oct 23 @ 12:30 pm – 1:30 pm
Pizza Lunch: Kristian Finlator @ AY 119

Vastly Improved Simulations of the Hydrogen Reionization Epoch: Too Much for One Paper?

Oct
27
Fri
PDS Atmospheres Node meeting
Oct 27 @ 10:30 am – 11:30 am
Nov
3
Fri
Planetary Group meeting
Nov 3 @ 10:30 am – 11:30 am
Nov
6
Mon
Pizza Lunch: Ethan Dederick
Nov 6 @ 12:30 pm – 1:30 pm
Pizza Lunch: Ethan Dederick @ AY 119

Cool Science Results

Nov
9
Thu
Special Pizza Lunch: Jane Rigby
Nov 9 @ 1:00 pm – 2:00 pm
Special Pizza Lunch: Jane Rigby @ AY 119

Galaxy Evolution in High Definition Via Gravitational Lensing

Dr. Jane Rigby

Deputy Project Scientist for JWST, NASA Goddard Space Flight Center

Abstract: In hundreds of known cases, “gravitational lenses” have deflected, distorted, and amplified images of galaxies or quasars behind them.  As such, gravitational lensing is a way to “cheat” at studying how galaxies evolve:  lensing can magnify galaxies by factors of 10–100 times, transforming them from objects we can barely detect to bright objects we can study in detail.   For such rare objects, we are studying how galaxies formed stars at redshifts of 1–4, the epoch when most of the Universe’s stars were formed. For lensed galaxies, we can obtained spectral diagnostics that are currently unavailable for the distant universe, but will become routine with next-generation telescopes.

In particular, I’ll discuss MEGaSaURA, The Magellan Evolution of Galaxies Spectroscopic and Ultraviolet Reference Atlas, which comprises high signal-to-noise, medium spectral resolution (R~3300) spectra of 15 extremely bright gravitationally lensed galaxies at redshifts of 1.6<z<3.6.   The sample, drawn from the SDSS Giant Arcs Survey, are many of the brightest lensed galaxies known.  The MEGaSaURA spectra reveal a wealth of spectral diagnostics: absorption from the outflowing wind; nebular emission lines that will be key diagnostics for JWST, GMT, and TMT; and photospheric absorption lines and P Cygni profiles from the massive stars that power the outflow.