info:eu-repo/semantics/article
New achievements of ASTE: the atacama submillimeter telescope experiment
Autor
ITZIAR ARETXAGA MENDEZ
David Hughes
Resumen
ASTE is a 10-m submillimeter telescope operating in Atacama desert in northern Chile since 2002 by NAOJ and collaborators. Thanks to the excellent observing condition at the telescope site, ASTE has been producing numerous astronomical results from star forming regions, Galactic center, Magellanic clouds, nearby galaxies, and galaxy clusters. There has been three major improvements during the years 2007-2008: continuum camera "AzTEC", new SIS receiver "CATS345", and a wide-band spectrometer "WHSF". AzTEC is a 144 element bolometer array at 270 GHz, developed by University of Massachusetts and collaborators. The mapping speed reaches 10-30 arcmin²/hr/mJy². CATS345 is a side-band separation (2SB) SIS receiver developed by University of Tokyo and NAOJ. The IF bandwidth is 4 GHz with side-band rejection ratio better than 10 dB. We have achieved the typical system noise temperature of 200-400 K (SSB) within 330-360 GHz, the best value being 150 K (SSB) at the frequency of ¹²CO(J=3-2) at 345 GHz under a typical weather condition. The new spectrometer WHSF employs of an FX type auto-correlator, ultra-high speed sampler, and digital signal transmitter. It can be operated in two modes; 4096 MHz band-width x 2 IFs or 2048 MHz band-width x 4 IFs, both with 4096 channels in spectral resolution.