The Initial Mass Function of Low-Mass Stars and Brown Dwarfs in Young Clusters

Details The Initial Mass Function of Low-Mass Stars and Brown Dwarfs in Young Clusters The Initial Mass Function of Low-Mass Stars and Brown Dwarfs in Young Clusters

2000-04-27

arxiv.org/abs/astro-ph/0004386v1

Astrophys.J.540:1016-1040,2000

Astronomy and Astrophysics

Astrophysics

34 pages, 13 figures, for color image see http://cfa-www.harvard.edu/~kluhman/trap/colorimage.jpg

Scientific paper

10.1086/309365

We have obtained images of the Trapezium Cluster (140" x 140"; 0.3 pc x 0.3 pc) with the Hubble Space Telescope Near-Infrared Camera and Multi-Object Spectrometer (NICMOS). Combining these data with new ground-based K-band spectra (R=800) and existing spectral types and photometry and the models of D'Antona & Mazzitelli, we find that the distributions of ages of comparable samples of stars in the Trapezium, rho Oph, and IC 348 indicate median ages of \~0.4 Myr for the first two regions and ~1-2 Myr for the latter. The low-mass IMFs in these sites of clustered star formation are similar over a wide range of stellar densities and other environmental conditions. With current data, we cannot rule out modest variations in the substellar mass functions among these clusters. We then make the best estimate of the true form of the IMF in the Trapezium by using the evolutionary models of Baraffe et al. and an empirically adjusted temperature scale and compare this mass function to recent results for the Pleiades and the field. All of these data are consistent with an IMF that is flat or rises slowly from the substellar regime to about 0.6 Msun, and then rolls over into a power law that continues from about 1 Msun to higher masses with a slope similar to or somewhat larger than the Salpeter value of 1.35. For the Trapezium, this behavior holds from our completeness limit of ~0.02 Msun and probably, after a modest completeness correction, even from 0.01-0.02 Msun. These data include ~50 likely brown dwarfs. We test the predictions of theories of the IMF against various properties of the observed IMF.

Affiliated with

Also associated with

No associations

Rating

The Initial Mass Function of Low-Mass Stars and Brown Dwarfs in Young Clusters does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Initial Mass Function of Low-Mass Stars and Brown Dwarfs in Young Clusters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Initial Mass Function of Low-Mass Stars and Brown Dwarfs in Young Clusters will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-397611