UPDATE: Zenodo migration postponed to Oct 13 from 06:00-08:00 UTC. Read the announcement.

Poster Open Access

Unresolved Binary Stars Cause an Observed Mass Dependent Age Gradient in Upper Scorpius

Sullivan, Kendall; Kraus, Adam

Young stellar associations represent a key site for the study of star formation, but to accurately compare observations to models of stellar evolution, the age of an association must be determined. The Upper Scorpius star-forming region is the youngest section of the Scorpius-Centaurus OB association, which is the largest collection of nearby, young, low-mass stars. The true age of Upper Scorpius is not clear, and an observed mass-dependent age gradient in Upper Scorpius, as well as in other star-forming regions, complicates age measurements. We have conducted a synthetic red-optical low-resolution spectroscopic survey of a simulated analog to the Upper Scorpius star-forming region to investigate the effects of unresolved binary stars on age measurements of a stellar population. We find that the observed mass-dependent age gradient in Upper Scorpius can be explained by a population of undetected binary stars. For a simulated population with an age of 10 (RMS = 2) Myr, we measure an age of 10.5 (RMS = 3.5) Myr for F stars, and 7.5 (RMS = 5.8) Myr for M stars. This discrepancy is caused by the mass-dependent mass ratio distribution and the variable steepness of the mass-luminosity relation. Our results support the previously suggested 10 Myr age for Upper Sco, with a small intrinsic age spread.

Files (1.1 MB)
Name Size
cool_stars_poster.pdf
md5:0c145f5bfc105e1802c724612488c7ae
756.9 kB Download
poster_preview.png
md5:0664816997da735c69bfeb4bc9744f72
303.8 kB Download
  • Dotter, A. 2016, ApJS, 222, 8

  • Pecaut, M., et al. 2012, ApJ, 746, 154

  • Pecaut, M.; Mamajek, E., 2016, MNRAS. 461, 1

  • Preibisch, T., et al. 2002, AJ, 124, 1

  • Slesnick, C., et al. 2008, ApJ, 688, 1

  • Rizzuto, A., et al. 2015, MNRAS, 448, 3

161
128
views
downloads
All versions This version
Views 161161
Downloads 128128
Data volume 87.4 MB87.4 MB
Unique views 150150
Unique downloads 120120

Share

Cite as