Astrophysics with LLAMA through providing and integrating (band-9) receiver

• Grant number: 15/50359-0
• Support type: Regular Research Grants
• Duration: April 01, 2016 - March 31, 2018
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Astronomical Instrumentation
• Cooperation agreement: Netherlands Organisation for Scientific Research (NWO)
• Principal researcher: Jacques Raymond Daniel Lépine
• Grantee: Jacques Raymond Daniel Lépine
• Principal researcher abroad: W. Boland
• Institution abroad: Universiteit Leiden, Netherlands
• Home Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The plan is to establish a long-term collaboration between NOVA and IAG-USP, in science and in development of instruments, aiming to the best use of the LLAMA radio telescope with competitive receivers. There is a significant science case to be made for a single-pixel side-band separating receiver operating at 'band 9' frequencies (approx. 600 to 700 GHz) on a single-dish telescope at a site of exceptional atmospheric transmission. The lines emitting in Band 9 are unique probes of warm (~100 K) and/or dense (~10^7 cm-3) gas. This is material that is strongly tied to star formation: it is this densest gas that forms stars and it is the star formation activity that heats the gas to these temperatures, either directly through stellar irradiation (by direct warming or as a PDR) or through shocks associated with stellar outflows. Interesting chemical species can be accessed, including hydrides (D2H+, SH+, 13CH+, and HCI). Applications to Galactic science are plenty. Regions of massive star formation have rich line spectra, with the characteristics of the line emission changing strongly from sub-region to sub-region. Finding which regions are line rich is an essential first step to prepare ALMA proposals. The science case is not limited to galactic astronomy. In nearby galaxies, regions of star formation can be studied in a very similar way. A single-dish telescope with a band-9 receiver serves to find the regions inside the galaxies emitting most strongly in these highly excited lines, and find the wavelengths regions with most lines of interest. NOVA has strong expertise in band 9 receivers, since this Institute was responsible for the construction of 66 band 9 receivers for ALMA, and has a well-equipped laboratory for research at Terahertz frequencies. The main parts of our joint program include 1. Delivery of a Band-9 receiver cartridge built by NOVA, for LLAMA telescope; 2. Integration of LLAMA frontend including Band-9 and Band-S cartridges. The GARD lab from Gothenburg (Sweden) will deliver the band-S. These two receivers will be the first two in operation at LLAMA. 3. Joint technical R&D, first aiming to construct a band 9 receiver with image rejection and in a longer term to construct focal plane arrays. Arrays of heterodyne receivers will increase by a large factor the efficiency for obtaining maps of extended objects with LLAMA. Such cameras can be of interest for use in other areas and for spin-off to industry. Several workshops focusing both science and instrumentation will be organized within this collaboration. (AU)