The impact of chromospheric activity on observed initial mass functions
Abstract
Using recently established empirical calibrations for the impact of chromospheric activity on the radii, effective temperatures, and estimated masses of active low-mass stars and brown dwarfs, we reassess the shape of the initial mass function (IMF) across the stellar/substellar boundary in the Upper Sco star-forming region (age ~ 5-10 Myr). We adjust the observed effective temperatures to warmer values using the observed strength of the chromospheric Hα emission, and redetermine the estimated masses of objects using pre-main-sequence evolutionary tracks in the H-R diagram. The effect of the activity-adjusted temperatures is to shift the objects to higher masses by 3%-100%. While the slope of the resulting IMF at substellar masses is not strongly changed, the peak of the IMF does shift from ≈0.06 to ≈0.11 M ⊙. Moreover, for objects with masses
Citation
Stassun , K G , Scholz , A , Dupuy , T J & Kratter , K M 2014 , ' The impact of chromospheric activity on observed initial mass functions ' , Astrophysical Journal , vol. 796 , no. 2 , 119 . https://doi.org/10.1088/0004-637X/796/2/119
Publication
Astrophysical Journal
Status
Peer reviewed
ISSN
0004-637XType
Journal article
Rights
© 2014. The American Astronomical Society. All rights reserved.
Description
K.G.S. acknowledges NSF grants PAARE AST-0849736 and AAG AST-1109612. The work of A.S. for this paper has been supported by the Science Foundation Ireland through the grant 10/RFP/AST278.Collections
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