1
    Science at the ARO with ALMA-Style Frontends
Lucy M. Ziurys R.W. Freund And the Staff of ARO
2
The Arizona Radio Observatory

• ARO An independent research unit of Steward
  Observatory
• Consists of two mm/sub-mm Single Dish Telescope
  Facilities
• Sub-millimeter Telescope (SMT)
• - 10 m dish on Mt. Graham, Arizona at
  10,543 ft.
• - Surface accuracy 15 µm rms
• - Pointing good to 1 rms
• - ?B 80 at 230 GHz 49 at 490 GHz
• - Operation at ? 1 mm
• ? One of worlds best antennas
• Kitt Peak 12 m
• - Kitt Peak site 6,280 ft
• - ?B 75 at 70 GHz
• - 2 and 3 mm workhorse
• ? Begun to equip facilities with
• ALMA-type receivers

SMT
12 m
3
The New Technology of ALMA-Type Mixers

• New Type of SIS Mixers developed specifically
  for ALMA
• Sideband-Separating
• Two mixers with RF and IF Quadrature Hybrids
• obtain upper and lower sideband simultaneously
  but separated with good image rejection and two
  IF outputs
• 4 GHz instantaneous BW
• per IF
• ? Unequaled Stability
• Most sensitive SIS mixers
• ? Dual polarization 4 IFs

Perfect Devices for Single-Dish Spectroscopy ?
Emphasis of ARO
4
New ALMA-Type Receivers at ARO
1) 1 mm (210-280 GHz) Receiver SMT -
Utilizes ALMA Band 6 Mixers (NRAO) -
Sideband-Separating - Dual Polarization with
4 IFs - Tsys as good 105 K, SSB, on sky 2)
0.4 mm (600 - 720 GHz) Receiver SMT -
Utilizes ALMA Band 9 Mixers (SRON) - Dual
Polarization, currently DSB - Upgrade
planned to SBS Mixers 3) 3 mm (85 -116 GHz)
Receiver 12 m - Uses ALMA Band 3 Mixers
(HIA) - Double Polarization -
Sideband-Separating
New CO detections 0.4 mm
3 mm receiver at 12 m
5

• Mixer in hand to working receiver
• ? Not a trivial task
• ? 1mm receiver as an example

Mixer Block (from NRAO)
Dewar incorporated Into Receiver package
Incorporation into Insert (one per polarization
Inserts put into Dewar
6
The Power of the ARO ALMA-type Receivers

• Sensitivity

63 hours

• HCO J 1?0 line at 89 GHz
• Previous 3 mm receiver (NRAO vintage)
• with 63 hours integration

• Same spectrum
• New ALMA-type 3 mm receiver
• with 4 hours integration

7

• Stability

• Versatility

• Position-switched spectrum
• 4 offset
• ? note the baseline

• Four IF Mode with steerable IF frequency
• Dual polarization signals for 12CO and 13CO
• at 230 and 220 GHz simultaneously

8

• Image Rejection

CO Signal Sideband
H Pol
V Pol
CO J 1 0 115 GHz W51 New 3 mm ALMA-type
Receiver 12 m Dual Polarization
CO Image Sideband
H Pol
V Pol
Image Rejection gt 19 db H Pol gt 26 db V Pol
9
Science with ALMA-Type Receivers New Molecules

• Test of Receiver Sensitivity and Stability
• ? Ability to detect new molecules
• 1 mm receiver at SMT used for comparative
  spectral line survey of circumstellar envelopes
  of IRC10216 and VY CMa
• IRC10216 C-rich object at 150 pc
• VY CMa O-rich shell at 1.5 kpc
• Continuous coverage 215-285 GHz
• Compare O-rich and C-rich regimes
• Most sensitive 1 mm survey
• to date
• Typical Tsys lt 200 K (SSB)
• Survey 70 complete

10
Survey Results thus far..

• Two new oxide species in VY CMa PO and AlO
• Two phosphorus molecules in IRC10216 PH3 and
  HCP

VY CMa
Tenenbaum Ziurys 2008
Tenenbaum et al 2007
Tenenbaum Ziurys 2009
11
Re-discovering VY Canis Majoris

• Record Sensitivity at 1 mm enormous advantage
• Discovered interesting new morphology and
• chemistry in O-rich Shell of Supergiant VY CMa
• First new source of new interstellar molecules
  in
• 25 YEARS (after Orion, SgrB2, TMC-1, IRC10216)

• Random sporadic mass loss from photospheric
  supergranules
• Large convection cells in red giants,
  supergiants (Schwarzschild 1975)

12
Complex Chemistry in Planetary Nebulae

• Planetary Nebulae Final Stage for Intermediate
  Mass Stars
• Strong UV Radiation Field from Central White
  Dwarf Star
• ? Destroy all Molecules
• Study of oldest Planetary Nebula with ALMA
  receivers HELIX NEBULA
• ? Found numerous polyatomic species
• Detections of CCH, H2CO, C3H2
• Widespread distribution of HCO

Helix Nebula
1000
13
HCO J 1 ? 0 Helix Nebula
CO
CO
HCO thus far found at every position
14
VLBI at 1 mm of SgrA
SMT-JCMT
SMT-CARMA

• Angular size of SgrA 37 (16.9,-10.5) µsec
• ? 4 Schwarzschild radii
• Density determined rules out alternatives to MBH
• Probes size scales near Event Horizon
• (Doeleman et al. Nature 2008)

SMT-JCMT
15
In Conclusion

• Receivers utilizing ALMA-Type Sideband
  Separating Mixers
• NRAO/HIA Design
• Offer a major step forward in sensitivity and
  stability
• Have already been instrumental in
• ? Detecting new molecules at mK level
• ? Unraveling new molecular content of
  uninteresting sources
• Key Factor in success of 1 mm VLBI
• Bright Future for Exciting New Scientific
  Discoveries using increase in receiver
  performance with new ALMA Technology

Thank you to NRAO CDL, HIA, and SRON Also Thank
you to staff of ARO