April 23, 2019


Speaker: Jane Rigby (NASA-Goddard)

Contact Information: jane.r.rigby@nasa.gov

Title: A Magnified Vision of How Galaxies Evolve

Abstract:

In hundreds of known cases, "gravitational lenses” deflect, distort, and magnify images of galaxies behind them. 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. We have taken advantage of these natural telescopes to build Megasaura: The Magellan Evolution of Galaxies Spectroscopic and Ultraviolet Reference Atlas. Megasaura is an atlas of high signal-to-noise, medium spectral resolution (R~3000) spectra of 21 extremely bright gravitationally lensed galaxies at redshifts of 1.7<z<3.6. The Megasaura spectra reveal a wealth of spectral diagnostics: absorption lines from gas being blown out of the galaxy, emission lines from gas heated by newly-formed stars, and photospheric absorption lines and P Cygni profiles from the massive stars that power the outflow. These will be key diagnostics for future telescopes (JWST and beyond) that with Megasaura we can study now. Indeed, Megasaura will be the definitive spectral atlas of its kind until the advent of 20–30m ground-based telescopes in the late 2020s, giving insight into the processes by which galaxies evolve over cosmic time.

Visit Schedule:

Tuesday (23 Apr 2019):

  • 9:00 AM: Michael Strauss (025C Peyton)

  • 9:30 AM:

  • 10:15 a.m.: Astro Coffee/reception

  • 11:00 a.m.: Colloquium!

  • 12:15 p.m.: Bahcall lunch

  • 1:30 PM: Neta Bahcall (137)

  • 2:00 p.m.: Ed Jenkins (115)

  • 2:30 p.m.: Renyue Cen (111)

  • 3:00 p.m.: Sean Johnson (Peyton 103)

  • 3:30 p.m.: Tea with grad students

  • 4:00 p.m.: Jenny Greene (001)

  • 4:30 p.m.: Rachael Beaton (Petyon 107)

  • 5:00 p.m.: Evan Schneider (Peyton 107)

  • 5:30 p.m.: Jill Knapp

  • 6:00 p.m.: DINNER WITH HOST - meet in Grand Central

Dinner Sign-up (students have priority; 8 MAX) - add your name here:

1. Speaker: Jane Rigby

2. Faculty host: Michael Strauss

3. Postdoc host: Sean Johnson

4. Rachael Beaton

5. Evan Schneider

6. Renbin Yan

7.

8.

NO MORE THAN 8 PEOPLE (otherwise it is very difficult to properly interact with the speaker)