Asteroseismology with the Roman Galactic Bulge Time-Domain Survey

TL;DR

The paper discusses how the Roman Galactic Bulge Time-Domain Survey can enable asteroseismology of red giant stars, providing new insights into stellar populations in the Milky Way's bulge through precise photometry and complementary data.

Contribution

It identifies key photometric requirements and observational strategies for effective asteroseismology with Roman, highlighting its potential to study stellar populations in the Galactic bulge.

Findings

Photometric precision of 1 mmag per 15 min enables red clump star detection.

Repeat observations can improve data quality or expand stellar sample.

Synergies with Gaia and exoplanet studies enhance scientific returns.

Abstract

Asteroseismology has transformed stellar astrophysics. Red giant asteroseismology is a prime example, with oscillation periods and amplitudes that are readily detectable with time-domain space-based telescopes. These oscillations can be used to infer masses, ages and radii for large numbers of stars, providing unique constraints on stellar populations in our galaxy. The cadence, duration, and spatial resolution of the Roman galactic bulge time-domain survey (GBTDS) are well-suited for asteroseismology and will probe an important population not studied by prior missions. We identify photometric precision as a key requirement for realizing the potential of asteroseismology with Roman. A precision of 1 mmag per 15-min cadence or better for saturated stars will enable detections of the populous red clump star population in the Galactic bulge. If the survey efficiency is better than expected, we argue for repeat observations of the same fields to improve photometric precision, or covering additional fields to expand the stellar population reach if the photometric precision for saturated stars is better than 1 mmag. Asteroseismology is relatively insensitive to the timing of the observations during the mission, and the prime red clump targets can be observed in a single 70 day campaign in any given field. Complementary stellar characterization, particularly astrometry tied to the Gaia system, will also dramatically expand the diagnostic power of asteroseismology. We also highlight synergies to Roman GBTDS exoplanet science using transits and microlensing.