ARO: Arizona Radio Observatory

Link to ARO Web site

I. General project/facility description

1. Overview of the facility/project
   The Arizona Radio Observatory (ARO) is a unit of Steward Observatory at the University of Arizona. Its mission is to provide facilities to promote research and education in millimeter and sub-millimeter astronomy within the state of Arizona university system and to contribute to the radio astronomical community at large. The ARO operates the Submillimeter Telescope (SMT) 10m on Mt. Graham and the Kitt Peak 12m. Both instruments have long histories and are located in Arizona. ARO operates in association with the instrumentation lab of Professor C. Walker and the Astrochemistry lab of Professor L.M. Ziurys. Both groups have graduate students that are both observers and instrument builders. It also provides some unique facilities to faculty within the state and to the general astronomical community. The organization currently consists of 20 employees, with two more engineers and an additional staff scientist starting this spring.
   The ARO was formed in 2002 from the existing Submillimeter Telescope Observatory (SMTO) and the skeleton crew that ran the former National Radio Astronomy Observatory (NRAO) 12m on Kitt Peak. The SMTO was originally a joint project between the University of Arizona and the Max-Planck Institute fuer Radioastronomie. The SMT telescope is now the sole property of the University of Arizona, as is the Kitt Peak 12m. Steward Observatory started operating the 12m facility in 2000, the year NRAO and AUI ceased operations. It officially became property of the University of Arizona in 2003.
   The major areas of millimeter/sub-millimeter science pursued at Steward Observatory include studies of the structure and dynamics of late-type stars and planetary nebula, molecular cloud morphology, star formation, and astrochemistry of interstellar and circumstellar material. These investigations require heterodyne receivers for both sensitive molecular line searches and large-scale mapping of molecular emission. The ARO provides the broad frequency coverage required for many of the scientific studies.. The 12m receivers cover the 65-183 GHz range (2 and 3 mm windows), and the SMT supports 130-500 GHz receivers. Future instrumentation is planned to operate up to 1 THz. Many of these receivers are dual polarization and single sideband. The ARO also supports array receivers, at present, the 345 GHz, seven-pixel Desert Star array, to be followed by SuperCam. ARO is also actively involved in millimeter-wave VLBI, in collaboration with M.I.T. Haystack.

2. Managing institution and organization
   The ARO is part of Steward Observatory and the University of Arizona, and is therefore integrated into the university system. Its current director, Dr. Lucy Ziurys, is a faculty member in Astronomy and Chemistry. The ARO director reports to the Associate Director of Steward Observatory. Scientific guidance is provided by the Steward Observatory Council. Faculty members participate in ARO, as do graduate students and post-doctoral fellows.

3. Funding source(s)
   
   • University of Arizona: ~ 88% of budget
   • NSF: $155,000 for VLBI observations over 3 years, in collaboration with MIT
   • Research Corporation: $100K per year for 12m operation for 3 years
   • Academia Sinica Institute of Astronomy and Astrophysics: ~$100K per year in exchange for guaranteed observing time

4. Construction history and cost
   The SMT was constructed during the period 1992 to 1994. The total cost for the construction of the facilities was $10 million. The project was a joint project between the MPIfR and UA. The 12m construction history can be obtained from NRAO.

5. Operational history and cost
   The SMT was operated by the SMTO, a joint organization of the MPIfR and UA, during the decade 1992 - 2002. The approximate annual operating budget during this period was $1.5M-$1.7M, depending on the year. The Kitt Peak 12m was operated separately from 2000-2002 by Steward Observatory with a budget of approximately $450K per year. The ARO budget (2002-Present) is approximately $2.3M per year.

II. Technical details

1. Specifics of telescope/instrument
   The technical characteristics of the ARO telescopes are summarized below. Individual highlights are described in the following sections as well.

   	SMT	KP12m
   Site Elevation	10,453 ft.	6,280 ft
   Primary Reflector Diameter	10.0 m	12.0 m
   Prime Focus f/D	0.35	0.42
   Cassegrain focus f/D	13.8	13.8
   Surface Material	Carbon Fiber Reinforced Panels	Aluminum Panels
   Surface Accuracy	15 µ rms	75 µ rms
   Pointing Accuracy	2.5" rms	7" rms
   Aperture Efficiencies	77% at 230 GHz 49% at 490 GHz	52% at 70 GHz 49% at 115 GHz 32% at 230 GHz
   Receivers	Dual polarization SSB SIS:130-300 GHz Dual polarization DSB SIS: 320-360 GHz Single channel DSB SIS: 390-490 GHz 7-pixel 345 GHz array (March 2005) 870 µ 19-pixel bolometer	Dual polarization SSB SIS: 65-115 GHz Dual polarization SSB SIS: 120-180 GHz
   Backends	AOS : 2units, each with 1 GHz BW; 0.9 MHz resol. AOS : 1 unit with 250 MHz BW; 0.385 kHz resol. Chirp spectrometer: 215 MHz BW; 45 kHz resolution Filter banks: 2048 ch; 1MHz resol. (Feb. 2005)	Filterbanks: multiple resolutions Millimeter Autocorrelator (MAC) See details below.

   • 12 m backends

     Filterbanks	Filter Resolution	Available Channels
     	2 MHz 1 MHz 500 kHz 250 kHz 100 kHz 30 kHz	2 x 256 2 x 256 1 x 128 1 x 128 1 x 128 128
     MAC	Resolution	Effective Bandwidth
     	781.2 kHz 390.6 kHz 195.3 kHz 97.6 kHz 48.8 kHz 24.4 kHz 12.2 kHz 6.1 kHz	600 MHz 600 MHz 300 MHz 300 MHz 150 MHz 150 MHz 75 MHz 75 MHz

   • Spectral Capabilities
     The spectral coverage achieved by all ARO receiver systems is 65-300 GHz (almost continuously) and 320-500 GHz, with a gap between 375-390 GHz. The entire 65-300 GHz range is covered with dual polarization, single sideband receivers. A new 1-2 mm, dual-channel, single sideband system has been installed at the SMT. There is some spectral overlap between the telescopes (at 2mm) for Very Long Baseline Interferometry between the 12m and the 10m. At 129 GHz, the ~160 km baseline offers a resolution of 4 milliarcsec. The long-term plan is to cover an entire frequency octave in dual-channel, SSB systems.
   • Modern and Efficient Control Systems:
     Both the KP12m and the SMT now have control systems that operate with Linux base X86 hardware. These control systems consist of multiple processors in a highly distributed network. Because of the distributed design, the processing power is magnified many times over. The design lends itself to parallel processing such that many different tasks can be carried out simultaneously. The backend computers concentrate strictly on the process of data taking, while other tasks such as graphical displays, file servers and on-line analysis are handled by separate processes in other computers. For instance, while the file server is writing the just-completed scan to the data disks, the on-line analysis is reducing it and the graphics engine is displaying the results, the backend is already taking the next scan. In fact, while observing, the backend never stops. The new control system at the SMT has been in place and operational since November 2002. It replaced the VAX/CAMAC-based system which originated at the MPI. It has improved the efficiency of the SMT dramatically. "Dead-time" has decreased by a factor of two in regular observing modes (beam or position-switching) and has increased the data rates for on-the-fly mapping by a factor of 20. The SMT control system upgrade was done completely in-house by ARO staff, with assistance from the Steward Observatory Technical Division.
     
   • Remote Observing:
     Remote observing is built into the control systems at both telescopes. An astronomer can logon to either telescope from virtually anywhere in the world and initiate a software package in a matter of seconds that entirely mimics the system at the site. This capability is augmented by highly skilled telescope technicians on the site who perform all necessary local functions for the observer, such as tuning the receiver to a new frequency. The observer interacts with the site technician via a "chat window". Even a laptop computer can be used for remote observing. A unique software/hardware package has been developed over the years for this purpose, and has been thoroughly tested by observers from all over the world who use the remote capabilities. Moreover, it allows for extreme flexibility in telescope schedule, and is perfect for long-term monitoring programs and/or sudden targets of opportunity, such as the appearance of a new comet. Remote observing at the ARO is now routinely conducted from Taiwan (ASIAA) and South Africa (Potchefstroom University).

2. New capabilities anticipated/planned in next 5-10 years
   
   • Heterodyne Receivers:
     
     • The longer-term plan at the ARO is to equip the SMT with dual polarization, single sideband receivers from 120-660 GHz with an option for the 800 GHz mixers as well. These receivers will be incorporated into two separate dewars that are used with closed cycle Gifford-McMahon refrigerator systems: one dewar will contain the 120-300 GHz mixers, and the other the 300-660 GHz systems. The latter receiver will allow for dual-channel observations at one frequency OR simultaneous measurements at two separate frequencies. Rotation of a mirror system located on top of the dewar will select any two of the eight possible mixers.
     • Mixers for some of the higher frequency bands will be available on the short term through a collaboration with ASIAA, who are supplying the mixer junctions and blocks. In the longer term, ARO will produce its own mixer blocks. A high-precision Kern milling machine has just been purchased for this purpose through C. Walker.
   • Array Receivers:
     
     • Within the next year, Desert STAR (a 7-pixel, 345 GHz heterodyne array) will go into regular operation as a facility instrument on the SMT. Desert STAR is a collaborative effort between Steward Observatory and the University of Massachusetts. The typical noise temperature of each array pixel is ~60 K. The instrument's tuning range is ~320-370 GHz. The instantaneous IF bandwidth is 2 GHz. Initially, a 8 x 256 MHz array filterbank will be used as the backend. The filterbank will eventually be complemented by an autocorrelator system (built as part of the SuperCam project, see below). During an engineering run with Desert STAR in the spring of 2004 the main beam efficiency of the SMT was measured to be ~82%.
       
     • The NSF MRI program has recently funded $2M for the construction of a 64 pixel, 345 GHz array receiver for the SMT. The instrument known as SuperCam (Superheterodyne Camera) will be the first large format array receiver ever built at submillimeter wavelengths. SuperCam is a collaborative effort, with science and instrument team members from Caltech, NRAO, U. Mass, U. Va., U. Wisconsin, Harvard, U. of Cologne, and JPL. The SuperCam frontend will use waveguide and SIS technology similar to that of Desert STAR and is expected to have similar performance. The SuperCam backend will consist of 64 independent correlator chips, each supporting 500 MHz of IF bandwidth with <0.5 MHz of spectral resolution. SuperCam will be used to map the Galactic plane in a variety of molecular species, starting with the J=3->2 transitions of ¹²CO and ¹³CO.
   • Continuum Front-end:
     
     • NASA has recently awarded a grant to upgrade and install the University of Chicago/Northwestern Hertz Polarimeter on the SMT. The Hertz instrument consists of 32 hexagonally-packed, bolometric pixels optimized for operation in the 350 µm polarimeter. The project is a joint effort between Goddard Spaceflight Center, Northwestern University, the University of Chicago, and Steward Observatory. The first engineering runs with Hertz will take place in early 2006. GSFC is constructing a more efficient polarization modulator for Hertz which will be installed a year later.
   • Spectrometer Backends:
     
     • For weak line searches, an inherent part of astrochemistry, as well as for extragalactic studies, a very stable, wide bandwidth backend is necessary. For these purposes, a new filterbank spectrometer has been constructed for the SMT with a total of 2048 channels with 1 MHz resolution. This instrument is steerable in blocks of 256 channels to any one of 8 receiver inputs and to any segment of the 4-6 GHz I.F. at the SMT. It will be used in 2 x 1024 ch. for the dual polarization receivers, hence allowing for a 1 GHz of bandwidth per channel; in addition, it will be used in the 8 x 256 ch. mode to accommodate the 7 pixel Desert STAR array receiver.
     • The new filterbanks, called the "Forbes Filterbank" for its Project Engineer David Forbes, utilizes modern surface technology. It is built on Eurocards, with automatic calibration and IF leveling. It occupies three standard 19 inch racks. The construction of this system is complete and the instrument is in the final stages of testing. The complete set of 2048 channels is projected to be on the telescope by the end of February 2005. An additional bank of 512 channels with 250 kHz resolution filters is now in the construction phase.

III. User profile

1. % of "open skies" time
   For the year 2003, 34% of observing time went to non UA/MPIfR astronomers (31% KP12m and 37% SMT).

2. Institutional affiliations of users
   In 2003, ARO users represented some 43 institutions worldwide, roughly half from the US.

3. Student access, involvement, usage
   The ARO has explicitly stated in its calls for proposals that special attention will be given to graduate students. From the Arizona system, there were 9 graduate student involved in astronomical observations and technical developments at the ARO in 2003. Several of these now have completed their Ph.D.'s using ARO data, and several of them are mid-career. During 2003, there were several graduate students from outside institutions that used ARO, including students from U. Calgary, U.T. Austin, and MPIfR. More recent graduate student users are from U. Georgia, U.N.C.-Chapel Hill, and UA. Graduate student usage for 2003 is greater than 40% for the Kitt Peak 12m and ~25% for the SMT.
   The ARO also encourages undergraduate involvement in observations. During the past 5 years, at least 8 UA undergraduates have participated in research at the ARO, including observations, data reduction and analysis, presentations at meetings, and in publishing papers. Also, the Maria Mitchell Observatory REU program makes use of the ARO yearly. The REU group participates in routine remote observing, monitoring maser emission in hydrogen recombination lines, followed by a visit/observing run at the Kitt Peak 12m, usually in late spring/early summer, involving as many as a dozen undergraduate students.

IV. Science Overview

1. Current forefront scientific programs
   
   • Studies of mass loss, dust formation, and chemistry in the envelopes of cool giant and AGB stars, proto-planetary nebulae, and planetary nebulae
     • Chemical abundances and chemical processes; modeling of multi-transition spectral line data to constrain both spatial distributions and molecular abundances
     • Emphasis on important chemical tracers which are sensitive to C/O abundance ratio, and to non-equilibrium processes, including pulsation-driven shocks and photochemistry initiated by ambient UV in outer envelopes
     • Determining mass loss histories of AGB and post-AGB stars which are evolving to PN's by modeling observations of higher CO transitions at sub-millimeter wavelengths (e.g. J=4->3)
       Time history of mass loss rates as a constraint on post-MS stellar evolution models
     • Studies of dust formation and dust loss rates by sub-mm bolometry and dust emission modeling
       Comparison with gas loss rates from CO mm and sub-mm line observations to derive dust/gas ratios in AGB star envelopes for a range of mass loss rates and spectral types (M, S, and C)
     • Detection of new interstellar molecules in AGB Envelopes(IRC+10216, CRL 2688, CRL 618)
     • Surveys of refractory species in AGB Envelopes (MgNC, NaCl, NaCN, AlF, etc in CRL 2688, CRL 618, CIT 6, etc)
     • Survey of ¹²C/¹³C ratios using the N=1->0 transition of CN in C-rich envelopes, supergiants, and H-deficient stars.
     • Chemical modeling of circumstellar envelopes
   • CO: J=2->1 and 3->2 mapping surveys of molecular clouds and star forming regions
     • Fully-sampled on-the-fly (OTF) mapping of ~few square degree regions in CO and ¹³CO J=2->1 transitions with angular resolution of 32" toward Gem OB1, W3, W51, and 1 = 30° molecular clouds
     • Fully-sampled mapping of CO J=3->2 transition with 7-beam focal plane array at 21" resolution of these star-forming clouds
     • LVG and Monte Carlo excitation modeling with constraints from 2->1 and 3->2 maps to derive physical properties, relate to SF activity
   • Star Formation and Protoplanetary Disks
     • Probing dynamics and physical conditions in protoplanetary disks using vibrationally-excited lines (e.g. CS and HCN)
     • Studying molecular cloud formation/destruction mechanisms by 1) observing the impact of cluster formation on cloud energetics and 2) surveying the properties of cloud boundary region
     • Studies of molecules in MSX cores
   • Astrochemistry
     • Searches for new molecular species in circumstellar envelopes and molecular clouds (synergistic activity with spectroscopy studies in Ziurys laboratory)
     • Studies of chemistry in molecular clouds and AGB envelopes
     • Survey of "metal"-bearing species in AGB envelopes to establish the degree of circumstellar refractory material and evaluate refractory chemistry
     • Observations of N/O-bearing molecules in dense clouds (NO, N₂O, HNO, etc) to establish the nitrogen/oxygen chemical network
     • Observational studies of PDR chemistry through observations of molecular ions such as HOC⁺, CO⁺ and HCO⁺ (synergistic with construction of the new "velocity-modulation" molecular ion spectrometer in the Ziurys lab).
     • Studies of large organic species of biological interest in molecular clouds, including vinyl alcohol, glycolaldehyde, and dihydroxyacetone (synergistic with construction/operation of new Fourier transform microwave spectrometer in Ziurys lab)
   • Extragalactic Research
     • Survey of large scale ISM properties of spiral galaxies along Hubble sequence from CO: J=1->0 emission
       Physical conditions of the circumnuclear gas in nearby active galaxies
       The ISM in early-type galaxies
     • Dust emission in gamma-ray-burst host galaxies
     • Large-scale CO(J=3->2) mapping of nearby spirals observed in the Nobeyama Extragalactic Atlas
     • Ultra-luminous infrared galaxies in the Sub-mm
     • Zero-spacing observations for the SMA Extragalactic Survey at 345 GHz and for BIMA SONG project at 115 GHz
     • Observations of x-ray selected, early-type galaxies in CO: J=1->0 and 2->1 lines
     • CO studies of peculiar galaxies in Perseus cluster
     • Surveys of J=3->2 emission in nearby, face-on spiral galaxies
   • Studies of Isotope Ratios in Interstellar and Circumstellar Gas
     • Observations of CN rotational lines (¹²CN and ¹³CN) to establish the ¹²C/¹³C ratio in the Galaxy
     • Evaluation of chemical fractionation effects of CN
     • Studies of ³⁷Cl/³⁵Cl ratio in circumstellar gas using NaCl
     • Studies of ²⁴Mg/²⁵Mg/²⁶Mg ratio in CSE's using MgNC
   • International VLBI
     • Studies of SiO masers in circumstellar material, in particular using the SMT-12m baseline
     • Images of J=3->2, v=1 maser line of SiO towards supergiant VYCanis Majoris
     • 2mm and 1mm VLBI experiments performed in collaboration with international partners
     • Studies of quasars at 2mm on short SMT / 12m baseline
     • Detection of continuum emission from quasar 3C454.3 at 1mm using SMT / IRAM 30m transatlantic baseline (resolution: <32 µarcsec.)

2. Major discoveries (through 1999)
   
   • Detections of new interstellar molecules (vinyl alcohol, glycolaldehyde, KCN, AlNC, tentative detection of CrH, etc)
   • Measurement of ¹²C/¹³C and D/H ratios at outer edges of Galaxy (D_GC > 14 Kpc) via CN, HCN, HCO⁺, etc
   • Detection of fringes at 1mm towards 3C 454.3 using SMT-IRAM 30m transatlantic baseline: highest angular resolution in astronomy achieved: <32 µarcsec
   • Detection of the J=9->8 line of CO at 1.03 THz at SMT
   • Discovery of strong J=3->2 CO emission in nearby face-on galaxies

3. Science highlights of last 5 years
   
   • Detection of submm lines of HCN and SiO in AGB star envelopes
     • Strong submm emission in high-excitation lines of HCN in M-type AGB stars, and of SiO in carbon stars implies high abundances far from LTE chemistry model predictions
     • Strong evidence for non-equilibrium chemistry produced by pulsation-driven shocks in stellar atmospheres, and definitely NOT by photochemistry in outer circumstellar envelope
   • Discovery of two new HCN maser lines in optically bright carbon stars
     • In vibrationally-excited J=3->2 and 4->3 states in stars of moderate mass loss rates and modest visual extinctions
     • Masing action not detected in high-mass loss objects in these lines
   • Determination of recent mass loss histories for proto-planetary nebulae by observations of CO J=4->3, 3->2, and 2->1 lines with high S/N ratio
     • Detailed modeling of line intensities and shapes shows that these stars have undergone sharp increases in mass loss rates over last ~10⁴ years of AGB evolution, leading to ejection of entire outer envelope. Derived quantitative values for M-dot as a function of time will constrain models for post-MS stellar evolution leading to PN formation
   • Fully sampled maps of CO and ¹³CO J=2->1 lines in molecular cloud associated with Sh 254-258 H II regions at ~30" resolution show clear evidence for sequential star formation, and reveal additional cold, dense molecular cores which are likely sites for future formation of massive stars, possibly induced by effects of present star formation
   • New advances in understanding chemistry of refractory molecules in interstellar / circumstellar gas
     • Detections of new metal-bearing molecules (in chemist's dense) in circumstellar gas
     • Evaluation of the amount of refractory material in the gas phase
     • Studies of magnesium isotope ratios
     • Modeling of circumstellar LTE chemistry
   • Studies of Ion Chemistry in Molecular Clouds
     • Detection of HOC⁺, the metastable isomer of HCO⁺, and CO⁺ towards PDR regions
     • Evaluation of CO⁺ and HOC⁺ chemistry
   • Studies of Organic Chemistry in Molecular clouds leading to "Bio-Molecules"
     • Absolute confirmation of glycolaldehyde in SgrB2 (> 50 transitions observed)
     • Detection of vinyl alcohol in SgrB2
     • Observations to confirm interstellar glycine
   • VLBI Studies of SiO masers and AGNs using short (SMT-12m) and transatlantic baselines
   • Detection of molecules (H₂CO, HCO⁺, CH₃OH, etc) in recent comets (C/2002 T7, "Linear" and C/2001 Q4 "Neat", for example)
   • Monitoring of molecules in planetary atmosphere
     • Evaluation of atmospheric conditions and diurnal effects
   • Monitoring of hydrogen recombination and methanol masers on weekly/monthly basis
     • Modeling of maser action in progress to evaluate mechanisms
   • Detections of CO in central regions of 110 galaxies in ARO surveys
     • universal ISM properties found in disks of spiral galaxies
     • very high density gas detected in several nearby Seyfert galaxies
   • Detection of strong CO: J=3->2 emission in near-by face-on spiral galaxies
   • C I at 490 GHz detected in Seyfert/LINERS for the first time

4. Main future science questions to be addressed
   
   • Understanding the detailed physics of molecular cloud formation, core formation, and cloud destruction: What are the life-cycles of molecular clouds? How do they form, evolve, and become disrupted? How does matter cycle between atomic and molecular phases? How and under what conditions do molecular clouds form stars? How do outflows, shocks, and UV radiation regulate star formations? What are the strengths of magnetic fields in molecular clouds ? To shed new light on these long-standing questions, we will use the excellent capabilities of the SMT for high-fidelity molecular line imaging in the mm/submm bands to do CO mapping of molecular clouds in J=2->1 and 3->2 transitions over large areas with focal plane arrays. The target fields will be selected to emphasized those with significant new data that is or will be available at other wavelengths:
     • Selected GMCs within ~3 kpc, including SPITZER c2d Legacy project targets; and regions mapped in CO J=1->0 with FCRAO
     • Selected regions of galactic plane 1st quadrant, in coordination with SPITZER GLIMPSE project
     • One or more high-latitude translucent clouds
     Data analysis will incorporate LVG and 3-D Monte Carlo radiative transfer modeling to derive cloud properties and dynamics, and relate these to star formation activity revealed from data at other wavelengths. A program will also be initiated to measure the Zeeman effect (from Stokes parameters with MAC) in 3 mm lines of suitably-tunable molecules i.e. open-shell molecules
   • Mass loss, dust formation, and chemistry in the envelopes of cool evolved stars: How do dust formation rates depend on stellar properties and composition? What chemical processes produce the rich variety of molecular species detected in such envelopes? How does the mass loss affect or depend on the evolution of the star?
     Specific observational programs will include:
     • Studies of other vibrationally-excited HCN lines in a larger sample of carbon stars to try to determine excitation mechanisms and why some stars are masers, others are not
     • Chemistry of other elements in circumstellar envelopes: especially compounds containing Si, S, Mg, Al, Na, Fe; abundances as shock diagnostics; relationship to mass loss rates, photospheric composition, stellar properties, and evolutionary state
     • Dust emission properties by continuum observations and polarimetry with bolometer arrays
     • Searches for new molecules containing refractory elements, based on new laboratory data acquired "in-house"
     • Evaluation of gas-phase vs. solid-state refractory components
     • Comparison of gas-phase compositions with meteoritic material
     • Detailed modeling of circumstellar chemistry and contribution of shocks
     • Studies of heavy element isotope ratios to constrain nuclear processes
   • Astrochemistry
     • Refractory Chemistry: How do metal-bearing species form in circumstellar envelopes? How much refractory material remains in the gas-phase? How does circumstellar chemistry change with stellar evolution? How much molecular material survives the final stages of AGB mass loss? What are the constraints on dust grain composition ?
     • What are the carriers of the refractory elements in dense clouds? Are these elements all depleted into dust grains? Are we "missing" some potential interstellar species?
     • Ion Chemistry: What are the important molecular ions in PDR regions? How is their chemistry linked? Do PDR conditions produce some unique species? How does ion chemistry vary from PDR regions to dense clouds? What is the ionization balance in these objects?
     • Chemistry of large organic species: Are there limits on the complexity of interstellar species? Can gas-phase interstellar chemistry produce the precursors to molecules of true biological significance (sugars, amino acids, etc)? Can we actually conclusively identify complex species using radio and millimeter astronomy? What are the criteria for identification of large organic molecules? How are complex species formed in the ISM? Does life really begin in molecular clouds as opposed to planet surfaces? What is the role of comets in the transport of interstellar material to planet surfaces? How complex are molecules in comets?
   • Isotope ratios: Are there really isotope gradients in the Galaxy? What are the relative contributions of Galactic chemical evolution vs. chemical fractionation? What are the "true" tracers of ¹²C/¹³C ratio? What stars contribute to ¹²C and ¹³C?
   • VLBI: Is transatlantic VLBI feasible at 1mm? Can we image the "event horizon" of super-massive Black Holes, in AGN's and powerful radio galaxies? Can we "detect" the supposed black hole, Sgr A* ?
   • Extragalactic research: What are the properties of GMC's and GMA's in nearby galaxies? What are the differences between active, starburst and normal galaxies along the Hubble sequence? What are the properties of low-surface brightness galaxies?

5. Synergies with other major forefront facilities
   
   • Participation in International Millimeter VLBI
   • Provided backup observations for INTEGRAL and ODIN satellites
   • Participation in comet campaigns, including NASA Deep Impact Ground - Based Radio Science Team
   • Provided both zero-spacing data and target sources for millimeter interferometers, in particular, Berkeley interferometer group.
   • Galactic Plane surveys described above designed to complement existing efforts (e.g. the Molecular Ring Survey, the AST/RO Survey, and Spitzer Legacy Programs).
   • Heterodyne focal plane array technology being developed for the SMT is a collaborative effort between many institutions.

6. Unique contributions
   
   • Broad frequency coverage and many stable, sensitive receiver systems and backends that allow for deep line searches, complemented by an active supporting laboratory spectroscopy group that focuses on potential interstellar molecules - a prime combination for astrochemical studies; also an innovative instrument lab.
   • Two millimeter telescopes separated by ~150 km that results in a unique "short" VLBI baseline at 2 mm; both sites have masers, close enough to constitute a quasi-connected array; also currently in a crucial position for the worldwide mm VLBI network.
   • Routine remote observing that has allowed for weekly maser monitoring and flexible scheduling for unexpected targets of opportunity such as comets. (ARO telescopes operate 24 hours a day, October-July).

V. Education/Outreach activities

1. Visitor facility
   The ARO receives no outside funding currently so outreach activities are done on a "volunteer basis". Both telescopes routinely host small tour groups, at their request. The 12m, for example has participated in the TLRBSE program (Teacher Leaders in Research Based Science Education), allowing a large group of teachers to tour the facility and see it in action. Also, ARO has given tours of the 12 m to Cornell alumnae groups, and to groups sponsored by Harvard/Smithsonian. The 12 m also participates in Kitt Peak tours, sponsored by NOAO, and both telescopes have participated in Astronomy Camp at Steward Observatory.
   The 12 m this spring will also take part in the NASA Astrobiology Institute Arizona-U. Washington exchange. Faculty and graduate students from the life sciences from U. Washington will participate in several days observing at Kitt Peak at 4 facilities, one of which is the 12m. They will do a "lab" concerning observing and identifying organic species in space. Material explaining radio astronomy and molecular spectroscopy will be sent to the participants at U. Washington several weeks in advance. A tutorial will be given at Kitt Peak prior to the observing. The goal is to foster an appreciation for methods and techniques of the astronomical sciences to those from the life sciences, fostering exchange between the scientific disciplines and learning "to speak their language". This program will likely evolve to a yearly event.
   The SMT is also involved in scientific programs at Discovery Park, a space, science, and cultural center located in Safford, AZ. This center was established to help foster an appreciation and interest in science and technology in rural south-eastern Arizona (see www.discoverypark.com). The SMT staff gives tours of the telescope, as requested, every Saturday from April through November as part of the Discovery Park Observatory Tours.

2. Student programs
   The ARO has supported the REU program of Maria Mitchell Observatory on an annual basis. Maria Mitchell receives observing time for remote work and yearly, a group of students from Maria Mitchell come to the telescope to observe. The ARO dorms are made available to the whole group, so they can experience "real observing". As many as a dozen students have come one time to the 12m. Other REU groups would be welcome at ARO.
   The UA itself has very active graduate and undergraduate participation in real-time observing at the ARO. Through SORAL (Steward Observatory Radio Astronomy Lab), it also has graduate student participation in instrument-building for the ARO facilities.

3. Other (as apply)
   

VI. Documentation/website URLs

1. URL of facility website
   
   • Arizona Radio Observatory: http://aro.as.arizona.edu/
   • Ziurys Astrochemistry Group: http://www.chem.arizona.edu/faculty/ziur/ziur-group.html
   • Steward Observatory Radio Astronomy Laboratory: http://soral.as.arizona.edu/

2. URL of EPO website
   
   • ARO: http://aro.as.arizona.edu/outreach.htm
   • Steward Observatory: http://www.as.arizona.edu/outreach/outreach.html

3. URL(s) of any brief overviews of project/facility
   
   • SMT: http://aro.as.arizona.edu/smt_docs/smt_telescope_specs.htm
   • 12M: http://aro.as.arizona.edu/12m_docs/12_meter_description.htm

4. URL(s) of miscellaneous documentation
   
   • http://aro.as.arizona.edu/documentation.htm