September 10, 2019

Speaker: Alyssa Goodman

Contact Information: agoodman@cfa.harvard.edu

Title: Teasing Out the True Milky Way

Abstract: It has been nearly 100 years since the "Great Debate," where Heber Curtis correctly argued that Thomas Wright's 1750 ideas about our Milky Way being one of many "galaxies," each a flattish disk of a multitude of stars, was correct. Since then, astronomers have made sharper and sharper images of galaxies beyond our own, often revealing intricate sprial structure. But, for the mostpart, our potentially super-close-up view of our own Galaxy's structure has been ruined by our unfortunate vantage point within its disk. Work over the past century indicates that the Milky Way is a barred spiral, but even the Galaxy's number of arms is still at-issue. In this talk, I will discuss how four techniques are being combined to tease out the true structure of the Milky Way. In particular, our collaboration* is combining 3D-dust mapping, searches for extraordinarily long galactic filaments called "Bones," position-position-velocity observations of gas, and numerical simulations to create a new, and sometimes very surprising, view of our Galaxy. Unexpected results to be presented include: several-hundred-pc long, ~1-pc wide, gaseous "Bones" lying in, and likely defining, the gravitational mid-plane of the Milky Way; a 2.5 kpc-long damped sine wave with 200-pc amplitude that seems to be the Local Arm (and the undoing of "Gould's Belt"); and simulations that suggest the need for feedback and/or magnetic fields, and/or stranger physics (dark matter in the disk?) in order to explain the Bones and/or the Local Arm's Wave.

Visit Schedule:

MONDAY (Sep 09, 2019)

(visitor room: 105A )

  • 10:30 a.m.: Astro Coffee

  • 11:00 a.m.: Robert Lupton (basement; 25D)

  • 11:30 a.m.: Jill Knapp (Peyton 106)

  • 12:00 p.m.: Jo Dunkley (Grand Central, walk to Prospect)

  • 12:30 p.m.: take Alyssa to lunch! (Prospect 12:20--1:15pm)

  • 1:00 p.m.: Lachlan Lancaster (Peyton 032)

  • 1:30 p.m.: Luke Bouma (Peyton 023A)

  • 2:00 p.m.: Neta Bahcall (Peyton 137)

  • 2:30 p.m.: Jenny Greene (Peyton 001)

  • 3:00 p.m.: Bruce Draine (Peyton 108)

  • 3:30 p.m.: Melinda Soares-Furtado (Peyton 020)

  • 4:00 p.m.: Miles Cranmer (Peyton 012)

  • 4:30 p.m.: Brandon Hensley (Peyton 104) / David Spergel

  • 5:00 p.m.: Alwin Mao (Peyton 019)

  • 5:30 p.m.: Robert Vanderbei (209 Sherrerd Hall -- meet in visitor room Peyton 105A)

  • 6:00 p.m.: DINNER WITH HOST (Please note, the dinner will be a joint dinner with IAS/PU scheduled for Monday 9/9th) - meet in Grand Central

You may text Alyssa at 617-230-7080 if you are trying to find where she may be

Joint Dinner with IAS scheduled for Monday Sept.9th.

Dinner Sign-up (grad students & postdocs are encouraged; 8 MAX) - add your name here:

1. Speaker: Alyssa Goodman

2. Faculty host: Bruce Draine

3. Postdoc host: Philip Mocz

4.

5. Zack Li

6. Melinda Soares-Furtado

7. Robert Vanderbei

8. Alwin Mao

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