ALMA Science Workshop May 14-15, 2004 ca. Mar 2, 2004 The Large Millimeter Telescope

ALMA Science Workshop May 14-15, 2004 Gopal Narayanan, Min Yun, F. Peter Schloerb University of Massachusetts Luis Carrasco Instituto Nacional de Astrofisica, Optica, y Electronica presented on behalf of the INAOE-UMass LMT Collaboration

ALMA Science Workshop May 14-15, 2004 Sierra Negra The LMT Site ● state of Puebla, MX ● excellent mm-wave transmission ● 4600m elevation ● 19 degrees Latitude ● Benign conditions ● Development nearly complete Sierra Negra Pico de Orizaba

ALMA Science Workshop May 14-15, 2004 LMT Specifications

ALMA Science Workshop May 14-15, 2004 LMT Time Line ● 1997: Site Selection ● : Antenna Design ● : Site Preparation and installation of Foundation ● 2001: Factory Steel Fabrication and Trial Assembly ● : Installation of Steel at Site ● : Fabrication of Surface Panels ● : Installation of Surface Panels ● 2005: Commissioning Begins

ALMA Science Workshop May 14-15, 2004 LMT Design Surface Segments Elevation Wheels Alidade Foundation Backstructure Receiver Cabin

ALMA Science Workshop May 14-15, 2004 Construction at Site January 2001January 2002February 2002 May 2002 July 2002 April 2003

ALMA Science Workshop May 14-15, 2004 Present Status at Site April 2004

ALMA Science Workshop May 14-15, 2004 Initial LMT Instruments ● Spectral Line – SEQUOIA – 32 element array for 3mm band – Array Autocorrelation Spectrometers – Redshift Receiver – 3mm ultrawide band receiver – 1mm SIS Receiver ● Continuum – BOLOCAM II – 144 element focal plane array – SPEED – special array for spectral energy distribution measurements

ALMA Science Workshop May 14-15, 2004 ● 85 – 115 GHz dual-polarized 16 pixel receiver ● 5 – 20 GHz IF allows 2 lines to be observed simultaneously ● FCRAO/LMT On-the-Fly Mapping Technique with Focal Plane Arrays powerful for large scale-mapping SEQUOIA Goldsmith, Narayanan, Heyer, Snell & Brunt (2004)

ALMA Science Workshop May 14-15, 2004 Redshift Search Receiver ● Ultra-wideband receiver for astronomical search for the highly redshifted spectral lines from distant galaxies. ● GHz gives high probability of detecting one line from galaxies with redshift greater than 1.1 and 2 lines for Z > 3 2mm, 5mm PWV, T RCR = 60K

ALMA Science Workshop May 14-15, 2004 ● Dual polarization – two beams ● Backend spectrometer is analog autocorrelator with 6.5 GHz bandwidth per section. 30 MHz resolution.

ALMA Science Workshop May 14-15, 2004 LMT Redshift Measurements Simulations based on dusty QSO BR ULIRG Line Ratios LMT has sensitivity to conduct follow-up studies on objects discovered in continuum surveys.

ALMA Science Workshop May 14-15, mm SIS Commissioning Receiver for LMT (testbed for future focal-plane array)

ALMA Science Workshop May 14-15, 2004 First Generation Continuum Receivers for LMT BOLOCAM II Imaging continuum receiver copy of the BOLOCAM instrument (Caltech, JPL, Cardiff, Colorado) 144 element focal plane array - key technology for Herschel/SPIRE BLAST BOLOCAM detector array

ALMA Science Workshop May 14-15, 2004 LMT Continuum Studies of Distant Objects LMT will discover many 1000's of protogalaxies with continuum maps. Simulation by Chapin, Hughes and Gaztenaga - INAOE Simulation of ~1 hour LMT observation with Bolocam II at 1.1 mm 9.5x9.5 arcmin (0.02 sq. deg.) 0.5 mJy rms

ALMA Science Workshop May 14-15, 2004 SPEED designed to measure mm- wave SED of previously detected objects simultaneous multi- frequency measurements matched beams in all bands high per-pixel sensitivity takes advantage of new bolometer technologies TES detectors Frequency Selective Bolometers First Generation Continuum Receivers for LMT Ch.4 Ch.3 Ch.2 Ch.1 FSB Detector FSB Backshort

ALMA Science Workshop May 14-15, 2004 Protogalaxy Interrogation with SPEED SED of CFRS14A SPEED SPEED 5σ sensitivities after 4 minutes of integration at LMT.

ALMA Science Workshop May 14-15, 2004 Comparison of LMT to Other Telescopes

ALMA Science Workshop May 14-15, 2004 Performance Comparison With Respect to the LMT

ALMA Science Workshop May 14-15, 2004 Analog Autocorrelator ● Like digital autocorrelator but delays and multiplies done with analog circuitry. No input digitizer, so no loss of S/N. Much wider bandwidth practical. ● Analog delay lines Nyquist sampled for 8 GHz bandwidth. Only GHz used. ● 64 lags on each tapped line, 4 lines per board. 256 lags total giving 31 MHz resolution, all on a single circuit board. ● Taps are summed and multiplied with silicon diodes. ● Circuit board includes A/D converters and digital signal processing. ● 24 boards cover full receiver bandwidth of 144 GHz. ● Total materials cost about $10/resolution element.

ALMA Science Workshop May 14-15, 2004 LMT Sensitivity to Distant Dusty Starburst Galaxies

ALMA Science Workshop May 14-15, 2004 Operations The Large Millimeter Telescope Observatory ● LMTO Role – Telescope maintenance and operation – Development of plans for upgrades – Telescope user support – Outreach ● LMTO Organization – Governing Board composed of INAOE and UMass personnel oversees LMTO. – LMTO is separate entity with an indepentent Director and Staff.

ALMA Science Workshop May 14-15, 2004 LMTO: A Scientific Collaboration between the US and Mexico

ALMA Science Workshop May 14-15, 2004 LMT Site MM-wave Transmission 8mm ppt-H 2 O 2mm ppt-H 2 O 8mm H 2 O 2mm H 2 O Site Opacity Quartiles based on Radiometric Measurements Predicted Transmission for 2mm and 8mm ppt water vapor

ALMA Science Workshop May 14-15, 2004 Antenna Design ● Antenna Designer: MAN Technologie ● "Open Air" Design (no enclosure). ● Active Surface – 180 trapezoidal surface segments. – Actuators at four corners of segments. – open-loop lookup table for positioning. ● Use of Active Surface eliminates gravitational distortion as major error source.

ALMA Science Workshop May 14-15, 2004 Antenna Fabrication ● Steel Fabrication – Adriann's de Mexico, Tlanepantla, Mexico – Supervision by Antedo, Inc., Cupertino CA. – Steel Fabrication is complete; antenna being assembled at site ● Surface Panels – Design and Development by Composite Optics Inc. (COI), San Diego, CA – Fabrication at Adriann's de Mexico – Panel fabrication to begin this year.

ALMA Science Workshop May 14-15, 2004 LMT Surface Segment Surface Panel Subframe Actuator for Computer Control

ALMA Science Workshop May 14-15, 2004 Composite Optics Inc. San Diego CA Critical Design Review for First Panel

ALMA Science Workshop May 14-15, 2004