The Hubble Space Telescope Advanced Camera for Surveys Emission Line Survey of Andromeda. I: Classical Be Stars
M. Peters, J.P. Wisniewski, B.F. Williams, J.R. Lomax, Y. Choi, M., Durbin, L.C. Johnson, A.R. Lewis, J. Lutz, T.A.A. Sigut, A. Wallach, J.J., Dalcanton

TL;DR
This study uses Hubble Space Telescope data to analyze classical Be stars in Andromeda, revealing their distribution, evolution, and comparison with other galaxies, and providing insights into their transient disk phenomena.
Contribution
First detailed HST survey of Be stars in Andromeda, quantifying their fraction, spectral distribution, and transient disk behavior in a metal-rich environment.
Findings
Be stars constitute about 6% of B-type stars in Andromeda.
The Be fraction decreases with spectral subtype and metallicity.
Disk-loss and regeneration episodes occur at a rate of approximately 22% per year.
Abstract
We present results from a 2-epoch HST H emission line survey of the Andromeda Galaxy that overlaps the footprint of the Panchromatic Hubble Andromeda Treasury (PHAT) survey. We find 552 (542) classical Be stars and 8429 (8556) normal B-type stars in epoch # 1 (epoch # 2), yielding an overall fractional Be content of 6.15% 0.26% (5.96% 0.25%). The fractional Be content decreased with spectral sub-type from 23.6% 2.0% (23.9% 2.0%) for B0-type stars to 3.1% 0.34% (3.4% 0.35%) for B8-type stars in epoch # 1 (epoch # 2). We observe a clear population of cluster Be stars at early fractional main sequence lifetimes, indicating that a subset of Be stars emerge onto the ZAMS as rapid rotators. Be stars are 2.8x rarer in M31 for the earliest sub-types compared to the SMC, confirming that the fractional Be content decreases in…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
