Highlights - Volume 494-1 (January IV 2009)

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HIGHLIGHTS: this week in A&A

Volume 494-1 (January IV 2009)


In section 6. Interstellar and circumstellar matter

“Resolved 24.5 micron emission from massive young stellar objects”, by W.J. de Wit, M.G. Hoare et al., A&A 494, p. 157

One of the obstacles impeding the understanding of the mechanisms underlying high-mass star formation is the lack of high-resolution images at wavelengths (essentially the mid and far IR) where a substantial fraction of the protostellar luminosity is emitted. The Subaru 24.5 micron images presented by De Wit et al. in the article highlighted in this issue represent a step towards resolving this problem. Surprisingly, they find a 1/r density dependence in several objects in the inner envelope suggesting rotational support on scales of 1000 AU. 


In section 9. The Sun

“The solar chromosphere at high resolution with IBIS.II. Acoustic shocks in the quiet internetwork and the role of magnetic fields”, by A. Vecchio, G. Cauzzi, and K.P. Reardon, A&A 494, p. 269

The solar chromosphere is in a highly dynamic state and its heating is still a matter of hot debate. This study investigates new high-resolution ground-based imaging spectrometer data from the chromosphere and the underlying photosphere. The authors relate (chromospheric) acoustic shocks to the photospheric dynamics and magnetic field. They find that the magnetic field also plays an important role in structuring the quiet Sun chromosphere, i.e. outside strong magnetic field concentrations. 


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© Astronomy & Astrophysics 2009