Highlights - Volume 471-2 (August IV 2007)

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HIGHLIGHTS: this week in A&A

Volume 471-2 (August IV 2007)


VLA observations of the supernova remnant W44

The low-frequency radio emission and spectrum of the extended SNR W44: new VLA observations at 74 and 324 MHz”, by G. Castelletti, G. Dubner, C. Brogan, and N.E. Kassim, A&A 471, p. 515

The interaction of supernova remnants with surrounding molecular clouds is interesting both because of the effects on the surroundings (stimulating star formation, for example) and because of the effects on the remnant itself (particle acceleration, for example). This paper applies low-frequency radio techniques to the study of the well-known supernova remnant W44 and gives evidence that the radio spectral index varies considerably in the region of interaction.



IR integral-field spectroscopy of SN 1987A

Infrared integral field spectroscopy of SN 1987A”, by K. Kjaer, B. Leibundgut, C. Fransson, P. Gröningsson, J. Spyromilio, and M. Kissler-Patig, A&A 471, p. 595

SN 1987A in the Large Magellanic Cloud was the brightest supernova in the last few centuries and is close enough to study its transition to a supernova remnant. The authors use the SINFONI integral-field spectrograph supported by adaptive optics to obtain a dynamical map of the interaction between the inner circumstellar ring and the supernova shock and to map the cooling in the shocked material.


In section 1. Letters

“Low-mass lithium-rich AGB stars in the Galactic bulge: evidence for cool bottom processing?”, by S. Uttenthaler, T. Lebzelter, S. Palmerini, M. Busso, B. Aringer, and M.T. Lederer, A&A 471, p. L41

This paper reports the discovery of two asymptotic giant branch (AGB) stars with solar lithium abundance. The very probable conclusion is that an extra mixing process works below the convective envelopes of these stars. This may lead to a new picture of AGB nucleosynthesis.  


© Astronomy & Astrophysics 2007