Mass-Loss Rates for Massive Stars from Stellar Bowshocks VI
Abstract
Measuring spectral lines through ultraviolet (UV) spectroscopy is an effective method to determine mass-loss rates of massive stars with strong winds, consistently agreeing with theoretical predictions. However, in the limit of weak winds, UV-derived mass-loss rates differ from theory by a factor of ~100, known as the "weak-wind problem." In this study, we employ a novel method to measure mass-loss rates for massive stars with weak winds: balancing the momentum flux between the stellar wind and interstellar material using infrared bowshock data from the Spitzer 24-micron and Herschel 70- and 160-micron surveys. Optical spectra of early B-type and late O-type stars producing infrared bowshock nebulae were gathered using the Wyoming Infrared Observatory (WIRO) 2.3-meter and Apache Point Observatory (APO) 3.5-meter telescopes. After, spectra were interpolated with solar metallicity model spectra from the Potsdam Wolf-Rayet (PoWR) OB-I model grid to determine temperatures and surface gravities using temperature- and surface gravity-sensitive spectral line ratios. Our measured effective temperatures varied between 15,000- and 35,000-Kelvin and log-gravities between 2.8 and 4.1, consistent with typical early B-type and late O-type stars. With the aid of Gaia parallaxes and proper motions, we calculated mass-loss rates of massive stars that host stellar bowshock nebulae. A subset of the star sample is presented in this work. This work is supported by the National Science Foundation under REU grant AST 1852289.
- Publication:
-
American Astronomical Society Meeting Abstracts #243
- Pub Date:
- February 2024
- Bibcode:
- 2024AAS...24340806S