SDSS Milky Way as A Galaxy Symposium Series I

Bulges, bars and their influence on galaxies

3rd June 2021 - 10:00-12:00 EDT

Zoom info TBC - please register your interest using this form:
Registration Form

Add event to your Calendar

This is the first in a series of symposia organised by the SDSS IV Milky Way as a galaxy (MWAG) working group, and intended to promote science and discussion in and around the theme of understanding the context of the Milky Way within the broader realm of galaxy formation and evolution.

The scope of these symposia is to bring MWAG science out of telecons and into a more widely accessible domain and to trigger new ideas and discussion. The format will be three science talks, ~20(+10) minutes in length, followed by a 30 minute structured discussion.

The first symposium will be focused towards understanding bars, bulges and their influence on galaxies as a whole. We have three invited speakers (click the dropdown for abstracts):

The Milky Way as a barred galaxy in the LCDM cosmological context
Francesca Fragkoudi (ESO, Garching)

Abstract ABSTRACT TBC!

Effects of Bars on Galaxies: Gas Ionization and Stellar Distributions
Dhanesh Krishnarao (STSci, Baltimore)

Abstract Bars are prominent features of disk galaxies that transfer angular momentum across large scales, funnel gas across large radial extents, and drive resonances out to large scales. SDSS MaNGA and the citizen science project Galaxy Zoo:3D provide a unique sample to examine these complex phenomena through statistical studies. This talk will discuss some background of the large scale effects of bars based on N-body and hydrodynamic simulations of Milky Way like galaxies and apply their insight towards extragalactic samples of MaNGA galaxies. Two key results are: 1) gas surrounding bars tend to have unusual ionized gas properties compared to the rest of the disk and the inter bar regions. 2) The g-band light distribution of face on-barred galaxies may be used to identify bar resonances without requiring any kinematic information.

Signatures of the Galactic bar as seen by Gaia
Wilma Trick (MPA, Garching)

Abstract The central bar of our Galaxy is expected to strongly affect the structure of the stellar disk. Regions in the disk, where the orbits are in resonance with the bar's pattern speed, exhibit arches in velocity space and ridges in orbital action space. The biggest ridge is expected at the bar's outer Lindblad resonance (OLR). And indeed, Gaia DR2 has revealed seven different ridges, among them the "Hercules", "Sirius" and "Hat" moving groups. Are these observed ridges caused the bar? This talk will... (i) ...review how OLR orbits cause characteristic features in the radial velocities. This has been used to measure the bar's pattern speed from data, but has led to still unresolved ambiguities. (ii) ...show how the bar resonances contribute to vertical signatures observed in the disk. (iii) ...present that, by including metallicities as tracers for the stars' birth location, we might be able to distinguish between different resonances.

To be followed by a discussion and chaired jointly by Ted Mackereth and Nick Boardman, MWAG co-chairs

Please note that the symposium is intended for members of the SDSS IV and V collaboration and will have discussion focused on how the surveys within them can provide new insight on the problems. However, attendance by non-members is permissible with their agreement to commit to and abide by the SDSS non-disclosure agreement. Completion of the regsitration form and attendance will bind you to these terms.

All symposium attendees will be bound by the SDSS Code of Conduct.