SkyCURTAINs: Model agnostic search for Stellar Streams with Gaia data: Dataset

Table of Links

Abstract and 1. Introduction

2. Dataset

3. SkyCURTAINs Method and 3.1 CurtainsF4F

3.2. Line detection

4. Results

4.1. Metrics

4.2. Full GD-1 stream scan

5. Conclusion, Acknowledgments, Data Availability, and References

APPENDIX A: CurtainsF4F TRAINING AND HYPERPARAMETER TUNING DETAILS

A1. CurtainsF4F features preprocessing

A2. Hyperparameter tuning

2 DATASET

We demonstrate the SkyCURTAINs method on the Gaia Data Release 2 (GDR2) (Gaia Collaboration et al. 2018) dataset. GDR2 contains detailed astrometric and photometric information for over 1.3 billion sources in the Milky Way galaxy. The dataset characterises the source by the right ascension (𝛼) and declination (𝛿), the parallax (𝜛), proper motions in right ascension (𝜇𝛼) and declination (𝜇𝛿), the apparent magnitude (𝐺), and the colour information in the form of the GBP and GRP bands (𝐺BP − 𝐺RP). The newer Gaia Data Release 3 (GDR3) comes with improved measurements on radial velocities, but as the SkyCURTAINs method does not utilise this information, we use the GDR2 dataset. This allows for a direct comparison with the Via Machinae and CWoLa methods, which were developed using the GDR2 dataset.

The kinematic cuts are applied to reject distant stars that produce an overdensity in the proper motion at ∼ 0 mas/yr and reduce the sensitivity of the model to overdensities produced by stellar streams. The cut on magnitude removes stars that are too dim and ensures we have a uniform coverage of stars from the Gaia dataset. The cut on colour isolates older, low-metallicity stars, which are more likely to be stellar stream members.