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arXiv · 1006.2848

On the origin of [NeII] 12.81 micron emission from pre-main sequence stars: Disks, jets, and accretion

M. Guedel·F. Lahuis·K. R. Briggs·J. Carr·A. E. Glassgold·Th. Henning·J. R. Najita·R. van Boekel·E. van Dishoeck
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Abstract

(Abridged) We have conducted a study of [NeII] line emission based on a sample of 92 pre-main sequence stars mostly belonging to the infrared Class II, including 13 accreting transition disk objects and 14 objects driving jets and outflows. We find several significant correlations between L[NeII] and stellar parameters, in particular LX and the wind mass loss rate, dM/dt. Most correlations are, however, strongly dominated by systematic scatter. While there is a positive correlation between L[NeII] and LX, the stellar mass accretion rate, dMacc/dt, induces a correlation only if we combine the largely different subsets of jet sources and stars without jets. Our results suggest that L[NeII] is bi-modally distributed, with separate distributions for the two subsamples. The jet sources show systematically higher L[NeII], by 1-2 orders of magnitude with respect to objects without jets. Jet-driving stars also tend to show higher mass accretion rates. We therefore hypothesize that the trend with dMacc/dt reflects a trend with dM/dt that is more physically relevant for [NeII] emission. L[NeII] measured for objects without known outflows and jets is found to agree with simplified calculations of [NeII] emission from disk surface layers if the measured stellar X-rays are responsible for heating and ionizing of the gas. The large scatter in L[NeII] may be introduced by variations of disk properties and the irradiation spectrum, as previously suggested. The systematically enhanced [NeII] flux from jet sources clearly suggests a role for the jets themselves, as previously demonstrated by a spatially resolved observation of the outflow system in the T Tau triple.

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M. Guedel, F. Lahuis, K. R. Briggs, J. Carr, A. E. Glassgold, Th. Henning, J. R. Najita, R. van Boekel, E. van Dishoeck. 2010-06-14. On the origin of [NeII] 12.81 micron emission from pre-main sequence stars: Disks, jets, and accretion. https://doi.org/10.1051/0004-6361/200913971

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