The New Milky Way, in 3D

Presentation Date: 

Thursday, February 24, 2022


Harvard-Smithsonian Center for Astrophysics, Phillips Auditorium

Presentation Slides: 

Relevant Links


ABSTRACT: Just a century ago, astronomers were just barely recognizing that the Milky Way was a galaxy amongst many. Not-quite half a century ago, radio astronomers began to map out dense, star-forming clouds within the Milky Way. Until extraordinarily recently, the term “3D” in studies of star formation in the Milky Way and other galaxies referred to “position-position-velocity” maps made possible by spectral-line mapping using radio telescopes. While velocity measurements give deep insight into the workings of the interstellar medium, they cannot serve as a proxy for true distance within galaxies. So, researchers working with spectral-line cubes have long wished for reliable distance measurements that would bring a real 3D ISM into perspective. Today, thanks to near-miraculous innovations in data science and a wealth of new data from large surveys, including Gaia, it has just become possible to map out interstellar matter in true 3D. In this talk, I will explain how 3D dust mapping, and complementary techniques, are revealing a wealth of previously-unknown structures and phenomena associated with the “New” Milky Way. The features observed are literally “new,” in that they are caused by relatively short-timescale phenomena such as feedback from star formation, interactions of massive extragalactic objects with the Milky Way, and other as-yet unidentified phenomena. The specific results I will present include: discoveries of The Radcliffe Wave and the Perseus-Taurus Superbubble; 1-pc-resolution 3D maps of individual molecular clouds;  unraveling the origins of Barnard’s Loop in Orion; and the “Star Formation Frontier” at the surface  of The Local Bubble. I will conclude with a discussion of the wonderful opportunities and challenges these new 3D results pose to the theory and simulation communities. 

Visualization Software


WorldWide Telescope:

CoSpaces:, coded by Delightex:

Related Websites, with links to videos, press materials, journal articles (see below for QR code links to these sites)

Radcliffe Wave (Alves et al. 2020) website:

PerTau Supershell (Bialy et al. 2021) website:

Local Bubble (Zucker et al. 2022):

handout screenshot

In a hurry? These two short videos tell much of the 2021-22 story...

The Perseus-Taurus Supershell A Bubbly Origin for Stars around the Sun

Chronological Bibliography (★ = unexpected structural features  highlighted  in 2-24-22 colloquium)

Goodman AA (2012) Principles of high-dimensional data visualization in astronomy. Astronomische Nachrichten, 333:505. 

★Goodman AA, Alves J, Beaumont CN, Benjamin RA, Borkin MA, Burkert A, Dame TM, Jackson J, Kauffmann J, Robitaille T, Smith RJ (2014) The Bones of the Milky Way. The Astrophysical journal, 797:53.

Zucker C, Battersby C, Goodman A (2015) The skeleton of the milky way. The Astrophysical Journal, 815(1)

Zucker C, Schlafly EF, Speagle JS, Green GM, Portillo SKN, Finkbeiner DP, Goodman AA (2018) Mapping Distances across the Perseus Molecular Cloud Using CO Observations, Stellar Photometry, and Gaia DR2 Parallax Measurements. The Astrophysical Journal, 869(1):83. 

Zucker C, Battersby C, Goodman A (2018) Physical Properties of Large-scale Galactic Filaments. The Astrophysical Journal, 864 

Goodman AA, Borkin MA, Robitaille TP (2018) New Thinking on, and with, Data Visualization. arXiv [astro-ph.IM], 

Zucker C, Smith R, Goodman A (2019) Synthetic Large-scale Galactic Filaments: On Their Formation, Physical Properties, and Resemblance to Observations. The Astrophysical Journal, 887:186. 

Zucker C, Speagle JS, Schlafly EF, Green GM, Finkbeiner DP, Goodman AA, Alves J (2019) A Large Catalog of Accurate Distances to Local Molecular Clouds: The Gaia DR2 Edition. The Astrophysical Journal, 879:125. 

Zucker C, Speagle JS, Schlafly EF, Green GM, Finkbeiner DP, Goodman A, Alves J (2020) A compendium of distances to molecular clouds in the Star Formation Handbook. Astronomy & Astrophysics. Supplement series, 633:A51.  

★ Alves J, Zucker C, Goodman AA, Speagle JS, Meingast S, Robitaille T, Finkbeiner DP, Schlafly EF, Green GM (2020) A Galactic-scale gas wave in the solar neighbourhood. Nature, 578(7794):237–239. 

Das KK, Zucker C, Speagle JS, Goodman A, Green GM, Alves J (2020) Constraining the distance to the North Polar Spur with Gaia DR2. Monthly notices of the Royal Astronomical Society, 498(4):5863–5872.

★ Bialy S, Zucker C, Goodman A, Foley MM, Alves J, Semenov VA, Benjamin R, Leike R, Enßlin T (2021) The Per-Tau Shell: A Giant Star-forming Spherical Shell Revealed by 3D Dust Observations. The Astrophysical Journal, 919:L5. 

Zucker C, Goodman A, Alves J, Bialy S, Koch EW, Speagle JS, Foley MM, Finkbeiner D, Leike R, Enßlin T, Peek JEG, Edenhofer G (2021) On the Three-dimensional Structure of Local Molecular Clouds. The Astrophysical Journal, 919:35. 

★ Zucker C, Goodman AA, Alves J, Bialy S, Foley M, Speagle JS, Groβschedl J, Finkbeiner DP, Burkert A, Khimey D, Swiggum C (2022) Star formation near the Sun is driven by expansion of the Local Bubble. Nature, 601(7893):334–337. 

Foley, M, Goodman, AA, Zucker, C, Bialy, S, Forbes, J, Swiggum, C, Alves, J, Grosschedl, J, D’Onghia, E, Grudic, M, Bally, J, Soler, J, Leike, R, Ensslin, T (2022) A 3D View of Orion 1. Barnard’s Loop,  The Astrophysical Journal, in prep,