College of Science

SEMINAR: Matthew Povich [Cal Poly Pomona]

SEMINAR: The Duration of Star Formation in Galactic Giant Molecular Clouds

Sep 18, 2019 11:00 AM to Sep 19, 2019 12:00 PM at 8-241

Physics and Astronomy Seminar

September 12, 2019 11:00 am to 12:00 pm at Building 8, Room 241

Dr. Matthew Povich (Cal Poly Pomona)

The Duration of Star Formation in Galactic Giant Molecular Clouds 
Stars and planets are born in vast interstellar clouds of cold gas and dust called giant molecular clouds. As part of my sabbatical research at Caltech in Spring 2019, my collaborators and I have developed a novel infrared (1 - 8 µm) spectral energy distribution modeling methodology to place X-ray-identified, intermediate-mass (2 - 5 Msun), pre-main sequence stars (IMPS) on the Hertzsprung-Russell diagram. Compared to the more numerous and widely-studied low-mass stars, the temperature and luminosity of IMPS changes dramatically over the first few million years of evolution, hence IMPS serve as sensitive chronometers for measuring the ages of the youngest massive stellar populations in the Galaxy. In addition, bright X-ray emission from powerful stellar flares reveals the interior, convective structure of these magnetically-active stars, providing a new constraint for stellar evolutionary models. We apply our methodology to constrain the duration of star formation in a sample of ~20 massive star-forming regions in our Milky Way Galaxy that suffer significant differential reddening from obscuring foreground dust. The regions studied range in age from <1 Myr to ~10 Myr. We find that the duration of star formation, compared among the regions in our sample, generally agrees well with other age indicators, such as the presence of short-lived massive stars or the dust-processed total infrared emission from the clouds. Our results will improve the calibration of widely-used star formation rate tracers in the Milky Way and external galaxies.

10:50 am Refreshments

11:00 am Seminar

Building 8 - Room 241

For further information, please call (909) 869-4014