Proper motions in the disk of the Milky Way

An animated infographic is made with which illustrates how the wavy pattern in a plot of proper motions in galactic longitude as a function of longitude arises from the differential rotation of the Milky Way's disk. This is part of the outreach for Gaia DR3 in connection with the paper Gaia Data Release 3: Golden Sample of Astrophysical Parameters Gaia Collaboration, Creevey, O.L., et al., 2022, A&A.

Repository contents

• data folder with data from the Golden sample paper
• notebooks Jupyter notebooks with code to reproduce the analysis of the OBA sample and the Milky Way rotation curve modelling from the Golden Sample paper.
  • This folder also contains the Stan model code.
• mw_disk_rotation folder with the Processing and Java code for the animation of the rotating disk
• img, text, frames, video folder containing the images produced with the Python code, the video text and frames, and the video (frames and video are not stored on Github)

Python dependencies

NumPy, SciPy, Matplotlib, Astropy, PyGaia, CmdStanPy, HealPy, ArviZ, corner, Gala, Cartopy, scikit-learn

Reproducing the video

1. Download the necessary data (see this notebook).
2. Run python observational-plots.py -l and then do cp img/B_star_pml_vs_galon.png frames/
3. Run python intro-frames.py
4. Run the Processing script and do not forget to uncomment the line saveFrame("../frames/frame-######.png");. NOTE: this also generates a file lines-ffmpeg.txt (not stored on Github) which contains the timings and input text files for the captions with the Processing animation. It will be read by the bash-script below.
5. Run ./makevideo.sh

Tools used for making the video

• Main animation: Processing
• Stills: Python, Matplotlib, Cartopy
• Adding frames together and overlaying text: FFmpeg, GNU Bash

Credits

Credits: ESA/Gaia/DPAC

Video license: CC BY-SA 3.0 IGO

Acknowledgements

Based on the paper by the Gaia Collaboration Gaia Data Release 3: A Golden Sample of Astrophysical Parameters

Gaia Data Release 3 was published on June 13, 2022

Main Video/Data sets: ESA/Gaia/DPAC, Anthony Brown, Yves Frémat, Orlagh Creevey, Rosanna Sordo, Céline Reylé, Tineke Roegiers

Narrator: Orlagh Creevey

Ideas for video inspired by: Brunetti & Pfenniger, 2010, A&A 510, A34

Night sky image: ESA/Gaia/DPAC/André Moitinho, CC BY-SA 3.0 IGO

Milky Way image: Stefan Payne-Wardenaar/MPIA