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We describe a system being developed for measuring the shapes of the mirrors of the Fred Young Submillimeter Telescope (FYST), now under construction for the CCAT Observatory. "Holographic" antenna-measuring techniques are an efficient and accurate way of measuring the surfaces of large millimeter-wave telescopes and they have the advantage of measuring the wave-front errors of the whole system under operational conditions, e.g. at night on an exposed site. Applying this to FYST, however, presents significant challenges because of the high accuracy needed, the fact that the telescope consists of two large off-axis mirrors, and a requirement that measurements can be made without personnel present. We use a high-frequency (~300GHz) source which is relatively close to the telescope aperture (, Proceedings Volume 11445, Ground-based and Airborne Telescopes VIII SPIE Astronomical Telescopes + Instrumentation, 2020, Online Only Conference

*Doug.Henke@nrc-cnrc.gc.ca Optical design study for an 850 GHz commissioning camera module for CCAT-prime Doug Henke*a, Doug Johnstonea,b, Lewis B.G. Kneea, Scott Chapmanc, Colin Rossc, Michel Fichd, Thomas Nikolae, Steve K. Choif, Michael D. Niemackf,g, Stephen C. Parshleyf, Gordon J. Staceyf, Eve Vavagiakisf aNRC Herzberg Astronomy and Astrophysics Research Centre, Victoria, BC V9E 2E7, Canada; bDept. of Physics and Astronomy, Univ. of Victoria, Victoria, BC V8W 2Y2, Canada; cDept. of Physics and Atmospheric Science, Dalhousie Univ., Halifax, NS B3H 4R2, Canada; dDept. of Physics and Astronomy, Univ. of Waterloo, Waterloo, ON N2L 3G1, Canada; eCornell Center for Astrophysics and Planetary Science, Cornell Univ., Ithaca, NY 14853, USA; fDept. of Astronomy, Cornell Univ., Ithaca, NY 14853, USA; gDept. of Physics, Cornell Univ., Ithaca, NY 14853, USA ABSTRACT The CCAT-prime telescope, also known as the Fred Young Submillimeter Telescope (FYST), has an unblocked 6-m aperture designed for an extraordinarily wide field-of-view to be used in cosmological and galactic studies. Located at 5600 m near ALMA, the site has extremely dry conditions which make it particularly suited for observations at shorter sub-mm wavelengths. These attributes make CCAT-prime a potential platform for the next generation “Stage IV” cosmic microwave background experiment to conduct cosmology surveys of the extragalactic sky. CCAT-prime is also ideal for polarization studies within the galaxy and time-domain observations of nearby protostars. Prime-Cam is the wide-field, first-light instrument for CCAT-prime which, when complete, will contain seven instrument modules, including cameras and spectrometers, spanning mm through sub-mm wavelengths. Not all receiver modules are currently funded—including the 350 mm (~850 GHz) camera module that motivates the extraordinary high site of CCAT-p. Recognizing that an 850 GHz commissioning camera may be needed within the next 1–2 years, an optical design study was initiated where we purposely chose to reduce the scope, cost, and complexity while still preserving diffraction-limited optics, allowing for early science until the more powerful wide field science-grade camera module replaced it. In order to minimize the cost and scope of an 850 GHz commissioning camera, the optics plan for reuse of existing detectors (ACT MBAC TES detectors or BLAST-TNG MKIDs) and interface with the existing instrument module cartridge planned for Prime-Cam. Further simplifications include restricting the field-of-view and utilizing on-axis HDPE lenses without an anti-reflection layer. Discussion of optimal detector array F-lambda scaling, analysis of power loading, and feed horn coupling efficiency is included.

One of the most promising technologies to enable and enhance large survey capabilities for radio astronomy is the use of focal plane phased array antenna feeds, or more simply, phased array feeds (PAFs). PAFs allow for full and continuous coverage of the telescope’s field of view (FoV), and combined with cryogenic amplifiers, can result in survey speed improvements several orders of magnitude better than current multiple-feed-horn cameras. In order to locate cryogenic PAF elements and amplifiers at the telescope focal plane, a radio-frequency transparent vacuum vessel is required. Unlike typical radomes, the transmission properties must be exceptionally good when dealing with weak astronomical signals. The dome must also be sufficiently strong to carry the mechanical load on the vacuum vessel due to atmospheric pressure. Furthermore, the thermal loading on the internal cryogenic stages from the dome must be manageable for the cooling system. We have solved these problems by using a combination of welded polyethylene sheet to maintain the vacuum integrity and a closed-cell rigid foam to transfer the mechanical load to the opposite side of the vessel (a welded aluminum structure). The PAF elements and amplifiers operate at 20 K, while the foam transfers the mechanical load through an 80 K temperature stage, which also serves as a low-temperature radiation shield for the 20 K sections. The poor thermal conductivity of the foam, combined with G10-CR thermal standoffs on the opposite side, ensures the 80 K stage is sufficiently thermally isolated from room temperature conduction. The radiative loading is reduced via the usual employment of multi-layer insulation. In order to facilitate instrument maintenance and future upgrades, a modular PAF element mechanical strategy is employed. The design is such that a PAF-element-amplifier unit can be replaced without accessing the 20 K stage owing to the use of a “cryo-clamp” that uses materials with different coefficients of thermal expansion to tightly hold the units when cold. Cooling is supplied by three two-stage Gifford-McMahon cryo-coolers. This paper presents these design details for the cryostat of the ALPACA (Advanced L-Band Phased Array Camera for Arecibo), an instrument currently being designed and built for the 305 m radio telescope of the Arecibo Observatory in Puerto Rico.

Brigham Young University (BYU), in collaboration with Cornell University, is developing the Advanced Cryogenic L-band Phased Array Camera for Arecibo (ALPACA) as a user provided facility instrument on the Arecibo 305 m radio telescope. This instrument will consist of a fully cryogenic 69-element phased array feed (PAF) and real-time digital beamformer back end capable of producing 40 simultaneous dual polarized beams with approximately 305 MHz of instantaneous bandwidth at 1.4 GHz. The target design goal is to operate with a system noise temperature of 25 K. We report on simulation results and a preliminary overview of the design and progress of the instrument’s development.

We present the novel design of microfabricated, silicon-substrate based mirrors for use in cryogenic Fabry-Perot Interferometers (FPIs) for the mid-IR to sub-mm/mm wavelength regime. One side of the silicon substrate will have a double-layer metamaterial anti-reflection coating (ARC) anisotropically etched into it and the other side will be metalized with a reflective mesh pattern. The double-layer ARC ensures a reflectance of less than 1% at the surface substrate over the FPI bandwidth. This low reflectance is required to achieve broadband capability and to mitigate contaminating resonances from the silicon surface. Two silicon substrates with their metalized surfaces facing each other and held parallel with an adjustable separation will compose the FPI. To create an FPI with nearly uniform finesse over the FPI bandwidth, we use a combination of inductive and capacitive gold meshes evaporated onto the silicon substrate. We also consider the use of niobium as a superconducting reflective mesh for long wavelengths to eliminate ohmic losses at each reflection in the resonating cavity of the FPI and thereby increase overall transmission. We develop these silicon-substrate based FPIs for use in ground (e.g. CCAT-prime), air (e.g. HIRMES), and future space-based telescopes (e.g. the Origins Space Telescope concept). Such FPIs are well suited for spectroscopic imaging with the upcoming large IR/sub-mm/mm TES bolometer detector arrays. Here we present the fabrication and performance of multi-layer, plasma-etched, silicon metamaterial ARC, as well as models of the mirrors and FPIs., Comment: Presented at SPIE Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation III, June 14, 2018

We present the detailed science case, and brief descriptions of the telescope design, site, and first light instrument plans for a new ultra-wide field submillimeter observatory, CCAT-prime, that we are constructing at a 5600 m elevation site on Cerro Chajnantor in northern Chile. Our science goals are to study star and galaxy formation from the epoch of reionization to the present, investigate the growth of structure in the Universe, improve the precision of B-mode CMB measurements, and investigate the interstellar medium and star formation in the Galaxy and nearby galaxies through spectroscopic, polarimetric, and broadband surveys at wavelengths from 200 m to 2 mm. These goals are realized with our two first light instruments, a large field-of-view (FoV) bolometer-based imager called Prime-Cam (that has both camera and an imaging spectrometer modules), and a multi-beam submillimeter heterodyne spectrometer, CHAI. CCAT-prime will have very high surface accuracy and very low system emissivity, so that combined with its wide FoV at the unsurpassed CCAT site our telescope/instrumentation combination is ideally suited to pursue this science. The CCAT-prime telescope is being designed and built by Vertex Antennentechnik GmbH. We expect to achieve first light in the spring of 2021., Ground-based and Airborne Telescopes VII, June 10-15, 2018, Austin, USA, Series: Proceedings of SPIE; no. 10700

The CCAT-prime telescope is a 6-meter aperture, crossed-Dragone telescope, designed for millimeter and sub-millimeter wavelength observations. It will be located at an altitude of 5600 meters, just below the summit of Cerro Chajnantor in the high Atacama region of Chile. The telescope's unobscured optics deliver a field of view of almost 8 degrees over a large, flat focal plane, enabling it to accommodate current and future instrumentation fielding >100k diffraction-limited beams for wavelengths less than a millimeter. The mount is a novel design with the aluminum-tiled mirrors nested inside the telescope structure. The elevation housing has an integrated shutter that can enclose the mirrors, protecting them from inclement weather. The telescope is designed to co-host multiple instruments over its nominal 15 year lifetime. It will be operated remotely, requiring minimum maintenance and on-site activities due to the harsh working conditions on the mountain. The design utilizes nickel-iron alloy (Invar) and carbon-fiber-reinforced polymer (CFRP) materials in the mirror support structure, achieving a relatively temperature-insensitive mount. We discuss requirements, specifications, critical design elements, and the expected performance of the CCAT-prime telescope. The telescope is being built by CCAT Observatory, Inc., a corporation formed by an international partnership of universities. More information about CCAT and the CCAT-prime telescope can be found at www.ccatobservatory.org., Event: SPIE Astronomical Telescope + Instrumentation, 2018, Austin, Texas, USA; Proceedings Volume 10700, Ground-based and Airborne Telescopes VII; 107005X (2018)

CCAT-prime will be a 6-meter aperture telescope operating from sub-mm to mm wavelengths, located at 5600 meters elevation on Cerro Chajnantor in the Atacama Desert in Chile. Its novel crossed-Dragone optical design will deliver a high throughput, wide field of view capable of illuminating much larger arrays of sub-mm and mm detectors than can existing telescopes. We present an overview of the motivation and design of Prime-Cam, a first-light instrument for CCAT-prime. Prime-Cam will house seven instrument modules in a 1.8 meter diameter cryostat, cooled by a dilution refrigerator. The optical elements will consist of silicon lenses, and the instrument modules can be individually optimized for particular science goals. The current design enables both broadband, dual-polarization measurements and narrow-band, Fabry-Perot spectroscopic imaging using multichroic transition-edge sensor (TES) bolometers operating between 190 and 450 GHz. It also includes broadband kinetic induction detectors (KIDs) operating at 860 GHz. This wide range of frequencies will allow excellent characterization and removal of galactic foregrounds, which will enable precision measurements of the sub-mm and mm sky. Prime-Cam will be used to constrain cosmology via the Sunyaev-Zeldovich effects, map the intensity of [CII] 158 $\mu$m emission from the Epoch of Reionization, measure Cosmic Microwave Background polarization and foregrounds, and characterize the star formation history over a wide range of redshifts. More information about CCAT-prime can be found at www.ccatobservatory.org., Comment: Presented at SPIE Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX, June 15th, 2018

A common optical design for a coma-corrected, 6-meter aperture, crossed-Dragone telescope has been adopted for the CCAT-prime telescope of CCAT Observatory, Inc., and for the Large Aperture Telescope of the Simons Observatory. Both are to be built in the high altitude Atacama Desert in Chile for submillimeter and millimeter wavelength observations, respectively. The design delivers a high throughput, relatively flat focal plane, with a field of view 7.8 degrees in diameter for 3 mm wavelengths, and the ability to illuminate >100k diffraction-limited beams for < 1 mm wavelengths. The optics consist of offset reflecting primary and secondary surfaces arranged in such a way as to satisfy the Mizuguchi-Dragone criterion, suppressing first-order astigmatism and maintaining high polarization purity. The surface shapes are perturbed from their standard conic forms in order to correct coma aberrations. We discuss the optical design, performance, and tolerancing sensitivity. More information about CCAT-prime can be found at ccatobservatory.org and about Simons Observatory at simonsobservatory.org., Event: SPIE Astronomical Telescopes + Instrumentation, 2018, Austin, Texas, USA; Proceedings Volume 10700, Ground-based and Airborne Telescopes VII; 1070041 (2018)

We have developed a fully cryogenically cooled phased array feed (PAF) prototype camera and tested it on the Arecibo Radio Telescope in the summer of 2013. The camera consists of 19 dual-polarized elements on a hexagonal grid. The array elements are modified sleeve dipoles specially designed to be reinsertable, to include a noise injection coupling port and to operate at 18 K. Experimental results for observations on the Arecibo Telescope demonstrate performance of the cryogenic amplifiers, digital beamforming, and sensitivity over the PAF field of view, and provide an important proof of concept for a full-scale PAF receiver.

CMB-S4 is a proposed experiment to map the polarization of the Cosmic Microwave Background (CMB) to nearly the cosmic variance limit for the angular scales that are accessible from the ground. The science goals and capabilities of CMB-S4 in illuminating cosmic inflation, measuring the sum of neutrino masses, searching for relativistic relics in the early universe, characterizing dark energy and dark matter, and mapping the matter distribution in the universe have been described in the CMB-S4 Science Book. This Technology Book is a companion volume to the Science Book. The ambitious science goals of the proposed "Stage-IV" CMB-S4 will require a step forward in experimental capability from the current Stage-III experiments. To guide this process, the community summarized the current state of the technology and identify RD Receiver Optics; Focal-Plane Optical Coupling; and Focal-Plane Sensor and Readout.

This paper presents the current concept design for ALPACA (Advanced L-Band Phased Array Camera for Arecibo) an L-Band cryo-phased array instrument proposed for the 305 m radio telescope of Arecibo. It includes the cryogenically cooled front-end with 160 low noise amplifiers, a RF-over-fiber signal transport and a digital beam former with an instantaneous bandwidth of 312.5 MHz per channel. The camera will digitally form 40 simultaneous beams inside the available field of view of the Arecibo telescope optics, with an expected system temperature goal of 30 K.

This paper presents the results of the optical design tradeoff study that result in a reduction in complexity, size and cost of the structure for the sub-millimeter 25 m class CCAT telescope. Four optical configurations are presented; dual reflector Cassegrain and Gregorian options, and Gregorian Nasmyth and quasi-Nasmyth options. All configurations are shown to have diffraction limited performance.

We report the detection of 13CO(J=6-5) emission from the nucleus of the starburst galaxy NGC 253 with the redshift (z) and Early Universe Spectrometer (ZEUS), a new submillimeter grating spectrometer. This is the first extragalactic detection of the 13CO(J=6-5) transition, which traces warm, dense molecular gas. We employ a multi-line LVG analysis and find ~ 35% - 60% of the molecular ISM is both warm (T ~ 110 K) and dense (n(H2) ~ 10^4 cm^-3). We analyze the potential heat sources, and conclude that UV and X-ray photons are unlikely to be energetically important. Instead, the molecular gas is most likely heated by an elevated density of cosmic rays or by the decay of supersonic turbulence through shocks. If the cosmic rays and turbulence are created by stellar feedback within the starburst, then our analysis suggests the starburst may be self-limiting.

We have begun a survey of the [CI] 370 μ m fine structure line and of mid-J CO line emission from ULIRGs and starburst galaxies using our grating spectrometer ZEUS on the CSO. Here we present observations from six ULIRGs: Mrk 231, Zw 049.057, NGC 6240, Arp 299, Arp 220, and IRAS 17208. The CO (6-5)/FIR ratio in ULIRGs appears to be lower for ULIRGs than for LIRGs. Comparing the CO SEDs of the ULIRGs shows the necessity of obtaining CO rotational transitions up to at least J = 7 to properly constrain LVG models.

We report the detection of the 158 μ m [CII] line from the LIR ~ 1014 L ๏ galaxy FSC 10026+4949 at z = 1.12. This is the first detection of [CII] from the z = 1-3 epoch of enhanced starformation. The L [CII ] /L FIR ratio is 1.3 × 10-3 , larger than the ratio typically seen in local ULIRGs, but similar to that measured in normal and starburst galaxies. This high ratio implies that the UV fields powering the far-infrared emission are of only modest intensity, and that FSC 10026+4949 may be undergoing a galaxy-wide starburst.

We report the first detection of a mid-J isotopic CO line from an external galaxy. We detected the 13CO (6-5) line from the starburst nucleus of NGC 253. The line is suprisingly bright with an integrated intensity 7% of the 12CO (6-5) line, indicating optical depth in the 12CO line. Our LVG modeling shows that a single warm (T ~ 120 K), dense (n ~ 104 cm-3) component emits most of the 12CO and 13CO line emission from J = 2-1 through J = 7-6. The CO(1-0) line comes from an additional lower excitation envelope. About 60% of the total molecular gas mass within 70 pc of the nucleus is in the warm, dense component. We show that stellar far-UV photons or X-ray photons from a nuclear source are unlikely to be the primary sources of the gas heating. The most likely sources of heat are cosmic rays from the nuclear starburst or microturbulence within molecular clouds.

Forty molecular cloud cores in the southern hemisphere from the initial Spitzer Space Telescope Cores-to-Disks (c2d) Legacy program source list have been surveyed in 13CO(2-1), 12CO(4-3), and 12CO(7-6) with the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO). The cores, ten of which contain embedded sources, are located mostly in the Vela, Ophiuchus, Lupus, Chamaeleon, Musca, and Scorpius complexes. 12CO(7-6) emission was undetected in all 40 clouds. We present data of 40 sources in 13CO(2-1) and 12CO(4-3), significant upper limits of 12CO(7-6), as well as a statistical analysis of the observed properties of the clouds. We find the typical 13CO(2-1) linewidth to be 2.0 km/s for cores with embedded stars, and 1.8 km/s for all others. The typical 12CO(4-3) linewidth is 2.6 to 3.7 km/s for cores with known embedded sources, and 1.6 to 2.3 km/s for all others. The average 13CO column density derived from the line intensities was found to be 1.9 x 10^15 cm^(-2) for cores with embedded stars, and 1.5 x 10^15 cm^(-2) for all others. The average kinetic temperature in the molecular cores, determined through a Large Velocity Gradient analysis of a set of nine cores, has an average lower limit of 16 K and an average upper limit of 26 K. The average molecular hydrogen density has an average lower limit of 10^2.9 cm^(-3) and an average upper limit of 10^3.3 cm^(-3) for all cores. For a different subset of nine cores, we have derived masses. They range from 4 to 255 M_sun. Overall, our c2d sample of southern molecular cores has a range of properties (linewidth, column density, size, mass, embedded stars) similar to those of past studies.

This paper provides an update of the current efforts towards the development of a conceptual design for a large format cryogenic phased array camera instrument for the 305 m Arecibo radio telescope.

We describe the Short Wavelength Camera (SWCam) for the CCAT observatory including the primary science drivers, the coupling of the science drivers to the instrument requirements, the resulting implementation of the design, and its performance expectations at first light. CCAT is a 25 m submillimeter telescope planned to operate at 5600 meters, near the summit of Cerro Chajnantor in the Atacama Desert in northern Chile. CCAT is designed to give a total wave front error of 12.5 μm rms, so that combined with its high and exceptionally dry site, the facility will provide unsurpassed point source sensitivity deep into the short submillimeter bands to wavelengths as short as the 200 μm telluric window. The SWCam system consists of 7 sub-cameras that address 4 different telluric windows: 4 subcameras at 350 μm, 1 at 450 μm, 1 at 850 μm, and 1 at 2 mm wavelength. Each sub-camera has a 6’ diameter field of view, so that the total instantaneous field of view for SWCam is equivalent to a 16’ diameter circle. Each focal plane is populated with near unit filling factor arrays of Lumped Element Kinetic Inductance Detectors (LEKIDs) with pixels scaled to subtend an solid angle of (λ/D)2 on the sky. The total pixel count is 57,160. We expect background limited performance at each wavelength, and to be able to map < 35(°)2 of sky to 5 σ on the confusion noise at each wavelength per year with this first light instrument. Our primary science goal is to resolve the Cosmic Far-IR Background (CIRB) in our four colors so that we may explore the star and galaxy formation history of the Universe extending to within 500 million years of the Big Bang. CCAT's large and high-accuracy aperture, its fast slewing speed, use of instruments with large format arrays, and being located at a superb site enables mapping speeds of up to three orders of magnitude larger than contemporary or near future facilities and makes it uniquely sensitive, especially in the short submm bands.

The CCAT observatory is a 25-m class Gregorian telescope designed for submillimeter observations that will be deployed at Cerro Chajnantor (~5600 m) in the high Atacama Desert region of Chile. The Short Wavelength Camera (SWCam) for CCAT is an integral part of the observatory, enabling the study of star formation at high and low redshifts. SWCam will be a facility instrument, available at first light and operating in the telluric windows at wavelengths of 350, 450, and 850 μm. In order to trace the large curvature of the CCAT focal plane, and to suit the available instrument space, SWCam is divided into seven sub-cameras, each configured to a particular telluric window. A fully refractive optical design in each sub-camera will produce diffraction-limited images. The material of choice for the optical elements is silicon, due to its excellent transmission in the submillimeter and its high index of refraction, enabling thin lenses of a given power. The cryostat’s vacuum windows double as the sub-cameras’ field lenses and are ~30 cm in diameter. The other lenses are mounted at 4 K. The sub-cameras will share a single cryostat providing thermal intercepts at 80, 15, 4, 1 and 0.1 K, with cooling provided by pulse tube cryocoolers and a dilution refrigerator. The use of the intermediate temperature stage at 15 K minimizes the load at 4 K and reduces operating costs. We discuss our design requirements, specifications, key elements and expected performance of the optical, thermal and mechanical design for the short wavelength camera for CCAT.

Low-loss lenses are required for submillimeter astronomical applications, such as instrumentation for CCAT, a 25 m diameter telescope to be built at an elevation of 18,400 ft in Chile. Silicon is a leading candidate for dielectric lenses due to its low transmission loss and high index of refraction; however, the latter can lead to large reflection losses. Additionally, large diameter lenses (up to 40 cm), with substantial curvature present a challenge for fabrication of antireflection coatings. Three anti-reflection coatings are considered: a deposited dielectric coating of Parylene C, fine mesh structures cut with a dicing saw, and thin etched silicon layers (fabricated with deep reactive ion etching) for bonding to lenses. Modeling, laboratory measurements, and practicalities of fabrication for the three coatings are presented and compared. Measurements of the Parylene C anti-reflection coating were found to be consistent with previous studies and can be expected to result in a 6% transmission loss for each interface from 0.787 to 0.908 THz. The thin etched silicon layers and fine mesh structure anti-reflection coatings were designed and fabricated on test silicon wafers and found to have reflection losses less than 1% at each interface from 0.787 to 0.908 THz. The thin etched silicon layers are our preferred method because of high transmission efficiency while having an intrinsically faster fabrication time than fine structures cut with dicing saws, though much work remains to adapt the etched approach to curved surfaces and optics < 4" in diameter unlike the diced coatings.

We have designed and evaluated a Miniature Cryogenic Scanning Fabry-Perot (MCSF) interferometer which can be inserted into the optical path of a mid-IR camera to observe fine structure lines in the 25-40 μm wavelength regime. The MCSF uses free standing metal meshes as its filters and can scan over a length of ~2 mm. The short wavelength range in which the MCSF will be used requires very tight fabrication tolerances to maintain the parallelism of the meshes to within 0.15 μm and to obviate the need for dynamic parallelizing adjusters. A monolithic notch flexure design delivers these properties and minimizes the number of moving parts, maximizing reliability. The scanning mechanism includes a cryogenic stepper motor that drives a miniature fine-adjustment screw via a worm gear assembly. This allows for a step resolution of 1 step ~ 14 nm when operating in full step mode. Finite Element Analysis of the MCSF’s monolithic flexure guided the design and confirmed that the MCSF will remain within required limits over the course of operation. We developed the MCSF for use in the mid-IR camera FORCAST on the 2.5 meter SOFIA telescope.

We have developed a fully cryogenically cooled, 19-element phased array feed (PAF), prototype camera for the Arecibo Radio Telescope. The 19 PAF elements are dual polarized dipoles over a ground plane, and they sit behind a 70 cm diameter vacuum window transparent to RF.

We report first science results from our new spectrometer, the 2nd generation z(Redshift) and Early Universe Spectrometer (ZEUS-2), recently commissioned on the Atacama Pathfinder Experiment telescope (APEX). ZEUS-2 is a submillimeter grating spectrometer optimized for detecting the faint and broad lines from distant galaxies that are redshifted into the telluric windows from 200 to 850 microns. It utilizes a focal plane array of transition-edge sensed bolometers, the first use of these arrays for astrophysical spectroscopy. ZEUS-2 promises to be an important tool for studying galaxies in the years to come due to its synergy with ALMA and its capabilities in the short submillimeter windows that are unique in the post Herschel era. Here we report on our first detection of the [CII] 158 $\mu m$ line with ZEUS-2. We detect the line at z ~ 1.8 from H-ATLAS J091043.1-000322 with a line flux of $(6.44 \pm 0.42) \times 10^{-18} W m^{-2}$. Combined with its far-infrared luminosity and a new Herschel-PACS detection of the [OI] 63 $\mu m $ line we model the line emission as coming from a photo-dissociation region with far-ultraviolet radiation field, $G \approx 2 \times 10^{4} G_{0}$, gas density, $n \approx 1 \times 10^{3} cm^{-3}$ and size between ~ 0.4 and 1 kpc. Based on this model, we conclude that H-ATLAS J091043.1-000322 is a high redshift analogue of a local ultra-luminous infrared galaxy, i.e. it is likely the site of a compact starburst due to a major merger. Further identification of these merging systems is important for constraining galaxy formation and evolution models.

We have recently detected the [CII] 157.7 micron line in eight star forming galaxies at redshifts 1 to 2 using the redshift(z) Early Universe Spectrometer (ZEUS). Our sample targets star formation dominant sources detected in PAH emission. This represents a significant addition to [CII] observations during the epoch of peak star formation. We have augmented this survey with observations of the [OI] 63 micron line and far infrared photometry from the PACS and SPIRE Herschel instruments as well as Spitzer IRS spectra from the literature showing PAH features. Our sources exhibit above average gas heating efficiency, many with both [OI]/FIR and [CII]/FIR ~1% or more. The relatively strong [CII] emission is consistent with our sources being dominated by star formation powered PDRs, extending to kpc scales. We suggest that the star formation mode in these systems follows a Schmidt-Kennicutt law similar to local systems, but at a much higher rate due to molecular gas surface densities 10 to 100 times that of local star forming systems. The source of the high molecular gas surface densities may be the infall of neutral gas from the cosmic web. In addition to the high [CII]/FIR values, we also find high [CII]/PAH ratios and, in at least one source, a cool dust temperature. This source, SWIRE 4-5, bears a resemblance in these diagnostics to shocked regions of Stephan's Quintet, suggesting that another mode of [CII] excitation in addition to normal photoelectric heating may be contributing to the observed [CII] line., Comment: Accepted for publication in Astrophysical Journal. To appear in December 20, 2014, V797 - 2 issue

We have built a new long-slit grating spectrometer (ZEUS-2) for observations in the submillimeter wavelength regime (200-650 μm). ZEUS-2 is optimized for observations of redshifted far-infrared spectral lines from galaxies in the early Universe. The spectrometer employs three transition-edge sensed bolometer arrays, allowing for simultaneous observations of multiple lines in several telluric windows. Here we will discuss the optical, mechanical, and thermal requirements of ZEUS-2 and their subsequent design and performance. The entire instrument is cooled using a pulse tube cryocooler and an adiabatic demagnetization refrigerator. The cryogen-free approach enables remote control of the cooling system and allows for deployment of ZEUS-2 to telescope sites where access is limited. The compact and lightweight design is also within the size and weight constraints of several submm telescopes, making ZEUS-2 deployable at a variety of sites. ZEUS-2 completed a successful engineering run at the CSO on Mauna Kea in May 2012, and we plan to have our science-grade array system deployed on the APEX telescope in Chile for a science run in the fall of 2012.

We have recently commissioned the 2nd generation redshift(z) and Early Universe Spectrometer (ZEUS-2) at the Caltech Submillimeter Observatory. ZEUS-2 is a long-slit grating spectrometer (R~1000) for observations in the submillimeter wavelength regime that is optimized for observations of redshifted far-infrared spectral lines from galaxies in the early universe. Here we report on the design and first light performance of the first TES bolometer array installed in ZEUS-2. This array features 280 pixels each 1.26 mm square and arranged to provide ~35 pixel spectra at ~8 spatial positions on the sky. A 1/4-wavelength back short of 100 micron and gold mesh absorber matching the impedance of free space provides near 90% quantum efficiency for the 350 and 450 micron telluric windows. Array readout is done using SQUID multiplexers and the Multichannel Electronics. We will also report on the progress to install two additional arrays tuned to provide similar performance across the remaining telluric windows between 200-850 microns.

We report the first detections of the [NII] 122 {\mu}m line from a high redshift galaxy. The line was strongly (> 6{\sigma}) detected from SMMJ02399-0136, and H1413+117 (the Cloverleaf QSO) using the Redshift(z) and Early Universe Spectrometer (ZEUS) on the CSO. The lines from both sources are quite bright with line-to-FIR continuum luminosity ratios that are ~7.0\times10^{-4} (Cloverleaf) and 2.1\times10^{-3} (SMMJ02399). With ratios 2-10 times larger than the average value for nearby galaxies, neither source exhibits the line-to-continuum deficits seen in nearby sources. The line strengths also indicate large ionized gas fractions, ~8 to 17% of the molecular gas mass. The [OIII]/[NII] line ratio is very sensitive to the effective temperature of ionizing stars and the ionization parameter for emission arising in the narrow-line region (NLR) of an AGN. Using our previous detection of the [OIII] 88 {\mu}m line, the [OIII]/[NII] line ratio for SMMJ02399-0136 indicates the dominant source of the line emission is either stellar HII regions ionized by O9.5 stars, or the NLR of the AGN with ionization parameter log(U) = -3.3 to -4.0. A composite system, where 30 to 50% of the FIR lines arise in the NLR also matches the data. The Cloverleaf is best modeled by a superposition of ~200 M82 like starbursts accounting for all of the FIR emission and 43% of the [NII] line. The remainder may come from the NLR. This work demonstrates the utility of the [NII] and [OIII] lines in constraining properties of the ionized medium., Comment: Accepted for publication in ApJ Letters; 16 pages, 2 tables, 3 figures

We have detected the CO(6-5), CO(7-6), and [CI] 370 micron lines from the nuclear region of NGC 891 with our submillimeter grating spectrometer ZEUS on the CSO. These lines provide constraints on photodissociation region (PDR) and shock models that have been invoked to explain the H_2 S(0), S(1), and S(2) lines observed with Spitzer. We analyze our data together with the H_2 lines, CO(3-2), and IR continuum from the literature using a combined PDR/shock model. We find that the mid-J CO originates almost entirely from shock-excited warm molecular gas; contributions from PDRs are negligible. Also, almost all the H_2 S(2) and half of the S(1) line is predicted to emerge from shocks. Shocks with a pre-shock density of 2x10^4 cm^-3 and velocities of 10 km/s and 20 km/s for C-shocks and J-shocks, respectively, provide the best fit. In contrast, the [CI] line emission arises exclusively from the PDR component, which is best parameterized by a density of 3.2x10^3 cm^-3 and a FUV field of G_o = 100 for both PDR/shock-type combinations. Our mid-J CO observations show that turbulence is a very important heating source in molecular clouds, even in normal quiescent galaxies. The most likely energy sources for the shocks are supernovae or outflows from YSOs. The energetics of these shock sources favor C-shock excitation of the lines., Comment: 18 pages, 2 figures, 6 tables, accepted by ApJ

ZEUS-2, the second generation (z)Redshift and Early Universe Spectrometer, like its predecessor is a moderate resolution (R~1000) long-slit, echelle grating spectrometer optimized for the detection of faint, broad lines from distant galaxies. It is designed for studying star-formation across cosmic time. ZEUS-2 employs three TES bolometer arrays (555 pixels total) to deliver simultaneous, multi-beam spectra in up to 4 submillimeter windows. The NIST Boulder-built arrays operate at ~100mK and are readout via SQUID multiplexers and the Multi-Channel Electronics from the University of British Columbia. The instrument is cooled via a pulse-tube cooler and two-stage ADR. Various filter configurations give ZEUS-2 access to 7 different telluric windows from 200 to 850 micron enabling the simultaneous mapping of lines from extended sources or the simultaneous detection of the 158 micron [CII] line and the [NII] 122 or 205 micron lines from z = 1-2 galaxies. ZEUS-2 is designed for use on the CSO, APEX and possibly JCMT.

Fully sampled degree-scale maps of the 13CO 2-1 and CO 4-3 transitions toward three members of the Lupus Molecular Cloud Complex - Lupus I, III, and IV - trace the column density and temperature of the molecular gas. Comparison with IR extinction maps from the c2d project requires most of the gas to have a temperature of 8-10 K. Estimates of the cloud mass from 13CO emission are roughly consistent with most previous estimates, while the line widths are higher, around 2 km/s. CO 4-3 emission is found throughout Lupus I, indicating widespread dense gas, and toward Lupus III and IV. Enhanced line widths at the NW end and along the edge of the B228 ridge in Lupus I, and a coherent velocity gradient across the ridge, are consistent with interaction between the molecular cloud and an expanding HI shell from the Upper-Scorpius subgroup of the Sco-Cen OB Association. Lupus III is dominated by the effects of two HAe/Be stars, and shows no sign of external influence. Slightly warmer gas around the core of Lupus IV and a low line width suggest heating by the Upper-Centaurus-Lupus subgroup of Sco-Cen, without the effects of an HI shell., Comment: 54 pages, 27 figures, 5 tables. To appear in ApJS. Preprint also available (with full-size figures) from http://www.astro.ex.ac.uk/people/nfht/publications.html Datacubes available from http://www.astro.ex.ac.uk/people/nfht/resources.html

We report the performance of Triplespec from commissioning observations on the 200-inch Hale Telescope at Palomar Observatory. Triplespec is one of a set of three near-infrared, cross-dispersed spectrographs covering wavelengths from 1 - 2.4 microns simultaneously at a resolution of ~2700. At Palomar, Triplespec uses a 1×30 arcsecond slit. Triplespec will be used for a variety of scientific observations, including moderate to high redshift galaxies, star formation, and low mass stars and brown dwarfs. When used in conjunction with an externally dispersed interferometer, Triplespec will also detect and characterize extrasolar planets.

The TEDI (TripleSpec - Exoplanet Discovery Instrument) will be the first instrument fielded specifically for finding low-mass stellar companions. The instrument is a near infra-red interferometric spectrometer used as a radial velocimeter. TEDI joins Externally Dispersed Interferometery (EDI) with an efficient, medium-resolution, near IR (0.9 - 2.4 micron) echelle spectrometer, TripleSpec, at the Palomar 200" telescope. We describe the instrument and its radial velocimetry demonstration program to observe cool stars., 6 Pages, To Appear in SPIE Volume 6693, Techniques and Instrumentation for Detection of Exoplanets III

The redshift (z) and early Universe spectrometer (ZEUS) is an echelle grating spectrometer optimized to study star formation in the universe from about 1--2 billion years after the Big Bang to the present epoch by observing spectral lines in the submillimeter bands. ZEUS has a resolving power R ˜ 1000 optimized for extragalactic point source sensitivity. At present, ZEUS employs a 1 × 32 pixel thermister-sensed bolometer array configured to deliver simultaneous 16-element spectra in the 350 and 450 μm windows for a point source. When completed, ZEUS will have a 12 × 64 pixel TES-sensed bolometer array, delivering an instantaneous 64-element (6.4% bandwidth) spectrum at 12 spatial positions on the sky. ZEUS can be used on most large-aperture submillimeter telescopes, including the JCMT, CSO, SMT, and APEX. We obtained our first light on the CSO in early April 2006. Our primary science goals are to (1) trace star formation in the early universe by observing redshifted far-IR fine structure lines from distant (z ˜ 0.7 - 6) galaxies, (2) measure the redshifts of optically obscured submillimeter galaxies by detecting their bright 158 μm [C II] line emission, and (3) study star formation in starbursts and ULIRGs by observing their [C I] and mid-J CO rotational line emission.

We present the results of a � 250 arcmin 2 mapping of the 205 �m [NII] fine-structure emission over the northern Carina Nebula, including the Car I and Car II HII regions. Spectra were obtained using the South Pole Imaging Fabry-Perot Interferometer (SPIFI) at the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) at South Pole. We supplement the 205 �m data with new reductions of far-IR fine-structure spectra from the Infrared Space Observatory (ISO) Long Wavelength Spectrometer (LWS) in 63 �m [OI], 122 �m [NII], 146 �m [OI], and 158 �m [CII]; the 146 �m [OI] data include 90 raster positions which have not been previously published. Morphological comparisons are made with optical, radio continuum and CO maps. The 122/205 line ratio is used to probe the density of the low-ionization gas, and the 158/205 line ratio is used to probe the fraction of C + arising from photodissociation regions (PDRs). The [OI] and [CII] lines are used to construct a PDR model of Carina. When the PDR properties are compared with other sources, Carina is found to be more akin to 30 Doradus than galactic star-forming regions such as Orion, M17, or W49; this is consistent with the view of Carina as a more evolved region, where much of the parent molecular cloud has been ionized or swept away. These data constitute the first ground-based detection of the 205 �m [NII] line, and the third detection overall since those of the COBE FIRAS and the KAO in the early 1990s. Subject headings: HII regions — infrared: ISM — ISM: individual (Carina nebula) — ISM: lines and bands — photon-dominated region (PDR) — submillimeter: ISM