The past year has been very productive at IRAM and we are pleased to announce two major achievements.
The New Generation Receivers operating at 2 mm was installed successfully at the end of 2007. The performances of these dual polarization, 4 GHz bandwidth receivers are excellent with SSB receiver temperatures of K over most of the frequency range (129 to 174 GHz). This opens the Plateau de Bure Interferometer to a new frequency window and allows observations at high spatial resolution in the 2 mm band, including the relatively unexplored GHz frequency range. In addition, the 1 mm receivers were upgraded with new triplers that extend the high frequency range to 267 GHz. Two results obtained during the commissioning of the 2 mm receivers and with the upgraded 1 mm receivers are presented later in this Newsletter, demonstrating what can be achieved using these new capabilities.
The next steps will be to equip all Plateau de Bure antennas with 350 GHz receivers and install a new broadband correlator (WIDEX), which will be available in early 2009. These upgrades will make the Plateau de Bure interferometer the world-leading facility of its kind and enable to conduct new scientific projects. The increased sensitivity of the receivers allows the detection of many weak lines in a single track, and the continuum detection of several source types so far considered weak (such as proto-planetary disks) in less than one track, enabling survey type studies at the interferometer.
On December 3rd, 2007, ESO and IRAM signed the Band 7 Cartridge production contract for 48 units. This is an important milestone for the overall ALMA project. During the pre-production contract, IRAM already delivered eight receivers with outstanding performances. The production contract includes the fabrication, assembly, test, and delivery of 48 field-replaceable front-end modules for the ALMA Band 7, covering GHz. The production team at IRAM, together with the ALMA Front End IPT, will do its best for this ambitious and challenging undertaking.
In 2008, a major upgrade is planned at the 30-meter telescope with the installation of a new series of dual polarization 4 GHz bandwidth receivers operating at 3, 2, 1, and 0.8 mm. The installation of these new receivers, which is planned for this fall, will provide a boost in sensitivity and observing capabilities at the 30-meter for the winter 2008/2009.
Finally, the weather conditions on the Plateau de Bure as of mid-February are exceptionally good and most of the numerous observing programs that requested the extended baseline configurations have now been completed.