Collaborative Research: Mass-Loss Rates for OB Stars Driving IR Bowshocks

点击翻译按钮获取中文摘要

Principal Investigators (PIs) Kobulnicky and Povich will improve measurements of wind driven mass loss from massive stars. Just like a boat moving through water, a stellar wind collides with the interstellar medium and creates a bowshock. The PIs will teach several hundred undergraduate students at Cal Poly Pomona and the University of Wyoming, and members of the Wyoming Lander high school astronomy club how to participate in the online Zooniverse-Milky Way Project. Students will analyze infrared images and characterize the bow shocks. University students will also participate in a summer observing program at the Wyoming Infrared Observatory (WIRO) and the Apache Observatory (APO). The team will determine the physical properties of over 400 stars.Post-main-sequence mass loss driven by stellar winds effects the stellar structure, chemical yield, the light curve of the supernova, and the formation of a compact object. The PIs apply the principle of momentum flux balance between a stellar wind impinging upon an ambient interstellar medium moving relative to the star to estimate the mass loss rate. The crowd-sourced measurements from archival Spitzer Space Telescope, Wide-field Infrared Survey Explorer (WISE) and Herschel Space Observatory datasets will constrain the geometry of the infrared stellar bow shock nebulae. Cross-matching with the GAIA database will yield stellar distances and proper motions. Students will reduce and analyze the data taken with the WIRO spectrograph and the APO Kitt Peak Ohio State Multi-Object Spectrograph (KOSMOS). The team will produce an empirically based prescription for wind-driven stellar mass-loss rates as a function of stellar temperature, gravity, rotation rate, and evolutionary stage, more than quadrupling previous samples.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.