Performance of the New 0.4 mm Receiver ( GHz) at the Sub- Millimeter Telescope of the Arizona Radio Observatory Jessica L. Edwards L.M. Ziurys R.W. Freund E.F. Lauria The University of Arizona The 66th Ohio State University International Symposium on Molecular Spectroscopy

Receiver Information Commissioned for general use at the SMT in January 2011 The mixers are double sideband SIS junctions provided by the Space Research Organization of the Netherlands (SRON) Same devices used for Band 9 of ALMA Covers frequency range from GHz ( arcsecond beam) Dual linear polarization with 4 GHz of IF bandwidth from 4-8 GHz

ARO Band 9 Receiver

Performance Receiver noise temperatures range from 75–90 K Average system temperatures are ~2,000 K for water vapor levels in the atmospheres ≤ 2 mm This kind of weather accounts for ~20% of available observing time between December and March (~600 hours) Main beam efficiencies at 690 GHz using Jupiter and Saturn were measured to be 61% and 52%, respectively

Focus on Venus NS Focus on Venus Pointing and Focusing Pointing on Saturn Focus on Saturn NS Focus on Saturn Pointing on Venus

Data! Baselines are stable 5 minute Position Switching scan on NGC 6537 PS 5’ CO(6-5) at 691 GHz Tsys ~ 2300 K

CO(6-5) NGC 6537 (The Red Spider Nebula) Young Planetary Nebula, 1,600 years old Extremely hot central white dwarf ~400,000 K K4-47 Young, compact PN 900-2,000 years old CO(6-5) ~0.2’

Schuster, Humphreys, & Marengo AJ 131, 603 O-rich Supergiant 40 solar masses High mass loss R Leo O-rich AGB Star 390 pc HCN(8-7)

Summary Good rx for observations closer to star and hot cores due to small beam size MoleculeFrequency (GHz) E upper (K) MoleculeFrequency (GHz) E upper (K) SO 15(14)-14(13) CO (6-5) SO 2 34(0,34)-33(1,33) HCO + (7-6) HCO + (8-7) SiC 2 17(4,13)-17(2,16) H 2 S 3(1,2)-3(0.3) SiS (34-33) N 2 H+ (7-6) HCN (8-7) CF + (6-5) HNC (7-6) HCl (1-0)

Acknowledgements Dr. Ziurys, Dr. Woolf Dr. Emily Tenenbaum, Lindsay Zack The rest of the Ziurys Group Arizona Radio Observatory Engineers, Operators NASA and NSF for funding