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Performance of the New 0.4 mm Receiver (602-720 GHz) at the Sub-Millimeter Telescope of
the Arizona Radio Observatory
Jessica L. EdwardsL.M. ZiurysR.W. FreundE.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 602-720 GHz (10-12 arcsecond beam)
• Dual linear polarization with 4 GHz of IF bandwidth from 4-8 GHz
Arizona
Observatory Radio
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
1 2 3
0.4
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
Arizona
Observatory Radio
CO(6-5)
NGC 6537 (The Red Spider Nebula)Young Planetary Nebula, 1,600 years oldExtremely hot central white dwarf~400,000 K
K4-47Young, compact PN
900-2,000 years old
CO(6-5)
~0.2’
~0.2’
Schuster, Humphreys, & Marengo. 2006 AJ 131, 603
O-richSupergiant
40 solar masses
High mass loss
R Leo O-rich AGBStar
390 pc
HCN(8-7)
HCN(8-7)
Summary• Good rx for observations closer to star and hot
cores due to small beam sizeMolecule Frequency
(GHz)Eupper (K)
Molecule Frequency (GHz)
Eupper (K)
SO 15(14)-14(13) 602.02165 221 CO (6-5) 691.47308 116
SO2 34(0,34)-33(1,33) 606.70344 516 HCO+ (7-6) 624.20846 119HCO+ (8-7) 713.34209 154
SiC2 17(4,13)-17(2,16) 607.61015 206 H2S 3(1,2)-3(0.3) 708.47074 137
SiS (34-33) 616.32827 371 N2H+ (7-6) 652.09558 125
HCN (8-7) 708.8770 153 CF+ (6-5) 615.36691 103
HNC (7-6) 634.51082 121 HCl (1-0) 625.91523 30
Arizona
Observatory Radio
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
Arizona
Observatory Radio