Band 2 Workshop NRAO May 29, 2013 ALMA Band 2: Future Prospects for Scientific Studies Lucy M. Ziurys Staff and Students Arizona Radio Observatory University of Arizona

Band 2 Workshop NRAO May 29, 2013 “3 mm Low” at the ARO 12 m In 2000: Arizona took over the former NRAO 12 m at Kitt Peak 3 mm Low Receiver (65 – 88 GHz): Previous generation SIS mixers Used for many science projects over past years Conducted MIC/MMIC test observations at ARO 12 m in spring 2013 ARO 12 m 3 mm Low receiver

Band 2 Workshop NRAO May 29, 2013 Important Molecular Transitions MoleculeFrequency (GHz) H 2 CO1 0,1 → 0 0, N2D+N2D+ J = 1→ HDO1 1,0 →1 1, HCPJ = 2→ DCO + J = 1→ DCNJ = 1→ SiOJ = 2→ H 13 CO + J = 1→ DNCJ = 1→ NH 2 D1 + 1,1 → 1 - 0, SO2 2 → HNO1 0,1 →0 0, Importance of 67 – 90 GHz Region Many known spectral lines Unique physical and chemical tracers Contains fundamental transitions of important molecules H 2 CO: Abundant molecule, excellent thermometer and biologically relevant Deuterated Species: DCO +, N 2 D+, DCN, HDO, NH 2 D HNO: Key species in N/O chemical network J = 2 → 1 lines of SiO, SO, HCP: Refractory and sulfur chemistry

Band 2 Workshop NRAO May 29, 2013 Deuterium: cosmological origin in universe (D/H ~ ) Abundance not altered by star formation D/H ratio: Examine chemical fractionation in ion-molecule reactions Significance of Deuterated Species in Band High D/H ratios found in molecular clouds Particularly high in COLD clouds Used to examine chemical pathways Tracer of cloud evolution J = 1 → 0 transition: very important

Band 2 Workshop NRAO May 29, 2013 Refractory Chemistry SiO: Related to refractory material, dust grain evolution Also known to trace jet structures (HH212: Cabrit et. al. 2012) HCP: Phosphorus analog of HCN Only observed in circumstellar envelopes (Agundez et al.; Milam et al.) Tracer of phosphorus chemistry in dense clouds ?

Band 2 Workshop NRAO May 29, 2013 New Molecules: Band 2 Zack, Halfen, & Ziurys, 2011, ApJ(Letters), 733, L36 T R * (mK) V LSR (km s -1 ) Searching for new molecules Many blended/contaminated transitions Band 2 may provide critical and/or confirming lines Case for FeCN (First Fe-bearing species) 84 GHz transition (J = 10.5 → 9.5): essential for identification

Band 2 Workshop NRAO May 29, 2013 Ubiquitous H 2 CO Excellent thermometer (multiple transitions) “Bio-marker”: Precursor to sugar Ribose (RNA, DNA) Common molecule in molecular clouds Abundant in Outer Galaxy (D GC ~ kpc) 72 GHz Transition FAVORABLE (1 01 → 0 00 ) H 2 CO 20.3 kpc Blair et al. 2008

Band 2 Workshop NRAO May 29, 2013 H 2 CO in Diffuse Clouds H 2 CO common in diffuse clouds Observed in absorption towards many site lines (Liszt and Lucas 2003, 2006, etc.) Abundance H 2 CO/H 2 ~ 4 x Factor of 5 less than cold molecular clouds 3C111

Band 2 Workshop NRAO May 29, 2013 H 2 CO in Planetary Nebulae: Helix Helix Nebula: one of oldest known PNe (~ 12, 000 yrs.) UV impinging on remnant shell material for some time H 2 CO widespread in Helix (Zack & Ziurys 2013) Abundance f (H 2 CO/H 2 )~ 0.3–2.1 × Helix Nebula ~1000 " T K ~ 30 K N(H 2 ) ~ 10 5 cm -3

Band 2 Workshop NRAO May 29, 2013 ~2’ H 2 CO in Red Spider Nebula Red Spider (NGC 6537): Young PNe at 1,600 yrs Highest excitation planetary nebula known Presence of Si VI emission Interesting bipolar morphology H 2 CO present with f ~ 2 x (relative to H 2 ) Edwards & Ziurys Ap.J. Letters, in press

Band 2 Workshop NRAO May 29, 2013 SgrB2(N): Galactic Center SgrB 2(N) at Band 2 Spectrum: GHz: ARO 12 m data Part of SgrB2(N) survey in 1,2,3 mm windows Halfen et al.

Band 2 Workshop NRAO May 29, 2013 Fairly dense in lines at 10 mK level (SSB) Many organic-type species (C 2 H 5 CN, HCOOCH 3,CH 3 OCH 3, etc.) Also unidentified lines (“U”)

Band 2 Workshop NRAO May 29, 2013 Finished survey near 69 GHz as part of MIC testing Comparative 12 m data: 7. 7 hours integration POSITION SWITCHING: Off Position: 30 ‘ in AZ Frequency of 69.2 GHz (same relative T. scale) SIS MIC

Band 2 Workshop NRAO May 29, 2013 Long integration at 72 GHz (H 2 CO): 31 hours Beam-switching towards IRC Notice image contamination !! SISMIC

Band 2 Workshop NRAO May 29, M Retirement: April 1, 2013 But additional observations must wait… 12 m now retired

Band 2 Workshop NRAO May 29, 2013 Speeches from Past and Current Directors… Mark Gordon Darrel Emerson

Band 2 Workshop NRAO May 29, 2013 Final Blessing of the 12 m Paul Gabor, S.J. Vatican Observatory

Band 2 Workshop NRAO May 29, 2013 Ceremonial Signing of the 12m Panel

Band 2 Workshop NRAO May 29, 2013 A moment of silence as the compressors are turned off for the last time.

Band 2 Workshop NRAO May 29, 2013 April 2, 2013: Work begins to dismantle old 12 m

Band 2 Workshop NRAO May 29, 2013 Lift Elevation Axis, Yoke, Pedestal from Dome

Band 2 Workshop NRAO May 29, 2013 Now outside dome with Tom Folkers

Band 2 Workshop NRAO May 29, 2013

In Conclusion Observations have already shown Band 2 has much to offer scientifically 12 tests suggest use of MIC or MMIC may be acceptable instead of SIS NRAO-style (Kerr/Pan designs) SIS hard to beat Concerns about stability and image rejection with MMIC/MIC’s receivers Image rejection: properly-matched mixers in down-converter Further use of MIC and MMIC needed to draw concrete conclusions ARO will pursue Band 2 with new 12 m Next priority after installation of Band 3 receiver

Band 2 Workshop NRAO May 29, 2013 ALMA Development Fund NSF URO