ASIAA The Yuan Tseh Lee Array (formerly AMiBA)


YTLA (formerly AMiBA) is designed, constructed, and operated by ASIAA, with major collaborations with the National Taiwan University Electrical Engineering (NTUEE) and Physics (NTUP) Departments, and the Australia Telescope National Facility (ATNF). Additional contributions were also provided by Carnegie Mellon University (CMU), the National Radio Astronomy Observatory (NRAO), and the Jet Propulsion Laboratory (JPL). The construction of YTLA includes a novel hexapod mount, a carbon fiber platform, carbon fiber reflectors, low-noise receivers, a broadband correlator, sensitive and stable electronics, a retractable cover, site infrastructures, and software development.

The YTLA is sited on the slope of Mauna Loa at an altitude of 3,400m, in the Big Island of Hawaii. The telescope was build and operated in two phases. The first phase comprised of seven 0.6m antennas, with scientific observations 2007 - 2008, had detected six galaxy clusters in the redshift range of 0.09 to 0.32. The second phase expanded the array to thirteen 1.2m antennas, enhancing the ability to detect clusters at higher redshifts.

The project completed the design study of YTLA (2001-2002), fielded a 2-element prototype on Mauna Loa (2002), contracted and constructed all components (2002-2005), secured and developed the site on Mauna Loa (2004), took delivery of all components (2005), and integrated and commissioned the system (2006). In Oct. 2006 the seven element system was dedicated to Academy President Yuan-Tsh Lee for his continued support of the project.

Science operations took place in 2007-2008, and ten science papers have been published in the Astrophysical Journal between 2009 and 2011. The 13-element 1.2m expansion was completed in June 2009, and it was followed by periods of intense re-commissioning to meet the more stringent requirements. The new array is shown to be 8 times more sensitive for point sources, increasing the observation speed by a factor of 60. Routine science operation has resumed in 2011.

Construction Progress

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The ground-breaking ceremony was held in April 2004. On March 23 2006, we have five receivers installed on the platform and get first light with single base line. The pictures show the site progress in past years.