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

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ARO Band 9Receiver

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

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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

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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

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