Bats of Skydusky Hollow, Bland County, Virginia

During the period 22 November 1999 – 11 October 2001, winter hibernacula surveys, spring staging/autumn swarming surveys, and summer surveys for bats were completed in caves of Skydusky Hollow, Bland County, Virginia. During winter, 12 caves were entered and 16,185 bats counted: 235 Myotis sodalis (Indiana bat), 14,475 Myotis lucifugus (little brown myotis), 12 Myotis septentrionalis (northern myotis), 7 Myotis leibii (eastern small-footed myotis), 1,441 Pipistrellus subflavus (eastern pipistrelle), and 15 Eptesicus fuscus (big brown bat). Myotis sodalis hibernated in thermally stable areas of 7 -9 ̊C. The largest concentration of M. lucifugus (n = 4,280) hibernated in an area that was cooler (6.5 ̊C) than areas used by M. sodalis. The remaining 6,300 M. lucifugus hibernated at temperatures similar to, or slightly cooler than, temperatures used by M. sodalis. Intra-cave (and possibly inter-cave) movements of M. lucifugus and M. sodalis during the season of hibernation concentrated bats in cooler areas of the caves. An unusually large concentration of P. subflavus (n = 920) hibernated in Coon Cave in a warm (8.6 – 9.7 ̊C, stable environment. Proportions of species of bats captured during spring staging and autumn swarming varied from proportions found during winter hibernation. Mating and perhaps other social functions affect patterns of autumn use. No concentration of bats used the caves during summer

Detectors and cryostat design for the SuMIRe Prime Focus Spectrograph (PFS)

We describe the conceptual design of the camera cryostats, detectors, and detector readout electronics for the SuMIRe Prime Focus Spectrograph (PFS) being developed for the Subaru telescope. The SuMIRe PFS will consist of four identical spectrographs, each receiving 600 fibers from a 2400 fiber robotic positioner at the prime focus. Each spectrograph will have three channels covering wavelength ranges 3800 {\AA} - 6700 {\AA}, 6500 {\AA} - 10000 {\AA}, and 9700 {\AA} - 13000 {\AA}, with the dispersed light being imaged in each channel by a f/1.10 vacuum Schmidt camera. In the blue and red channels a pair of Hamamatsu 2K x 4K edge-buttable CCDs with 15 um pixels are used to form a 4K x 4K array. For the IR channel, the new Teledyne 4K x 4K, 15 um pixel, mercury-cadmium-telluride sensor with substrate removed for short-wavelength response and a 1.7 um cutoff will be used. Identical detector geometry and a nearly identical optical design allow for a common cryostat design with the only notable difference being the need for a cold radiation shield in the IR camera to mitigate thermal background. This paper describes the details of the cryostat design and cooling scheme, relevant thermal considerations and analysis, and discusses the detectors and detector readout electronics

JWST's Cryogenic Position Metrology System

The James Webb Space Telescope will undergo a full system test in the cryogenic vacuum chamber A at the Johnson Spaceflight Center in order to verify the overall performance of the combined telescope and instrument suite. This will be the largest and most extensive cryogenic test ever undertaken. Early in the test system development, it was determined that precise position measurements of the overall hardware would enhance the test results. Various concepts were considered before selecting photogrammetry for this metrology. Photogrammetry has been used in space systems for decades, however cryogenic use combined with the size and the optical/thermal sensitivity of JWST creates a unique set of implementation challenges. This paper provides an overview of the JWST photogrammetric system and mitigation strategies for three key engineering design challenges: 1) the thermal design of the viewing windows to prevent excessive heat leak and stray light to the test article 2) cost effective motors and mechanisms to provide the angle diversity required, and 3) camera-flash life and reliability sufficient for inaccessible use during the number and duration of the cryogenic tests

Prime Focus Spectrograph - Subaru's future -

The Prime Focus Spectrograph (PFS) of the Subaru Measurement of Images and Redshifts (SuMIRe) project has been endorsed by Japanese community as one of the main future instruments of the Subaru 8.2-meter telescope at Mauna Kea, Hawaii. This optical/near-infrared multi-fiber spectrograph targets cosmology with galaxy surveys, Galactic archaeology, and studies of galaxy/AGN evolution. Taking advantage of Subaru's wide field of view, which is further extended with the recently completed Wide Field Corrector, PFS will enable us to carry out multi-fiber spectroscopy of 2400 targets within 1.3 degree diameter. A microlens is attached at each fiber entrance for F-ratio transformation into a larger one so that difficulties of spectrograph design are eased. Fibers are accurately placed onto target positions by positioners, each of which consists of two stages of piezo-electric rotary motors, through iterations by using back-illuminated fiber position measurements with a wide-field metrology camera. Fibers then carry light to a set of four identical fast-Schmidt spectrographs with three color arms each: the wavelength ranges from 0.38 {\mu}m to 1.3 {\mu}m will be simultaneously observed with an average resolving power of 3000. Before and during the era of extremely large telescopes, PFS will provide the unique capability of obtaining spectra of 2400 cosmological/astrophysical targets simultaneously with an 8-10 meter class telescope. The PFS collaboration, led by IPMU, consists of USP/LNA in Brazil, Caltech/JPL, Princeton, & JHU in USA, LAM in France, ASIAA in Taiwan, and NAOJ/Subaru.Comment: 13 pages, 11 figures, submitted to "Ground-based and Airborne Instrumentation for Astronomy IV, Ian S. McLean, Suzanne K. Ramsay, Hideki Takami, Editors, Proc. SPIE 8446 (2012)

Progress with the Prime Focus Spectrograph for the Subaru Telescope: a massively multiplexed optical and near-infrared fiber spectrograph

The Prime Focus Spectrograph (PFS) is an optical/near-infrared multi-fiber spectrograph with 2394 science fibers, which are distributed in 1.3 degree diameter field of view at Subaru 8.2-meter telescope. The simultaneous wide wavelength coverage from 0.38 um to 1.26 um, with the resolving power of 3000, strengthens its ability to target three main survey programs: cosmology, Galactic archaeology, and galaxy/AGN evolution. A medium resolution mode with resolving power of 5000 for 0.71 um to 0.89 um also will be available by simply exchanging dispersers. PFS takes the role for the spectroscopic part of the Subaru Measurement of Images and Redshifts project, while Hyper Suprime-Cam works on the imaging part. To transform the telescope plus WFC focal ratio, a 3-mm thick broad-band coated glass-molded microlens is glued to each fiber tip. A higher transmission fiber is selected for the longest part of cable system, while one with a better FRD performance is selected for the fiber-positioner and fiber-slit components, given the more frequent fiber movements and tightly curved structure. Each Fiber positioner consists of two stages of piezo-electric rotary motors. Its engineering model has been produced and tested. Fiber positioning will be performed iteratively by taking an image of artificially back-illuminated fibers with the Metrology camera located in the Cassegrain container. The camera is carefully designed so that fiber position measurements are unaffected by small amounts of high special-frequency inaccuracies in WFC lens surface shapes. Target light carried through the fiber system reaches one of four identical fast-Schmidt spectrograph modules, each with three arms. Prototype VPH gratings have been optically tested. CCD production is complete, with standard fully-depleted CCDs for red arms and more-challenging thinner fully-depleted CCDs with blue-optimized coating for blue arms.Comment: 14 pages, 12 figures, submitted to "Ground-based and Airborne Instrumentation for Astronomy V, Suzanne K. Ramsay, Ian S. McLean, Hideki Takami, Editors, Proc. SPIE 9147 (2014)