Astronomy and Astrophysics – Astronomy
Scientific paper
Nov 1996
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1996apj...471l..45n&link_type=abstract
Astrophysical Journal Letters v.471, p.L45
Astronomy and Astrophysics
Astronomy
20
Radio Continuum: Stars, Stars: Pre-Main-Sequence, Shock Waves, Stars: Formation
Scientific paper
Shocks associated with the supersonic infall of matter onto a protostellar disk are sources of potentially detectable radio free-free emission: a protostar of mass ~1.5[D/(100 pc)] Msolar is sufficient to generate an 8.4 GHz flux of 100 mu Jy from its protostellar disk when viewed face-on at a distance D. The free-free emission from an accretion shock is a good diagnostic of the mass of the protostar, which determines the area of the optically thick free-free emission from the shocked surface of the inner disk. Accretion shocks are a possible explanation of recent observations of the source NGC 1333 IRAS 4, in which the measured fluxes at 4.8 and 8.4 GHz exceed the values expected for circumstellar dust emission alone. The accretion shock explanation requires the presence in this source of a protostar of mass 3.5--4 Msolar, a value that is consistent with the observed bolometric luminosity only if accretion through the disk is nonsteady and only if the protostellar luminosity lies substantially below its main-sequence value, as indeed is predicted by theoretical models for the evolution of pre--main-sequence stars. We also discuss an alternative model in which the observed free-free emission arises in shocks produced by circumstellar winds impacting dense circumstellar material.
Hollenbach David J.
Neufeld David A.
No associations
LandOfFree
Free-Free Emission from Accretion Shocks 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 Free-Free Emission from Accretion Shocks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Free-Free Emission from Accretion Shocks will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1146439