99 results on '"Benford, Dominic"'
Search Results
2. Overview of the Roman Coronagraph Instrument
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Mennesson, Bertrand, Cady, Eric, Kasdin, Jeremy, Benford, Dominic, and Bailey, Vanessa
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- 2021
3. 2 mm GISMO Observations of the Galactic Center. I. Dust Emission
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Arendt, Richard G, Staguhn, Johannes G, Dwek, Eliahu, Mark R. Morris, Farhad Yusef-Zadeh, Benford, Dominic J, Kovacs, Attila, and Gonzalez-Quiles, Junellie
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Astronomy - Abstract
The central molecular zone, covering the inner 1° of the Galactic plane has been mapped at 2mm using the Goddard-IRAM Superconducting 2-Millimeter Observer (GISMO) bolometric camera on the 30 m IRAM telescope. The 21 resolution maps show abundant emission from cold molecular clouds, from star-forming regions, and from one of the Galactic center nonthermal filaments. In this work we use the Herschel Hi-GAL data to model the dust emission across the Galactic center. We find that a single-temperature fit can describe the 160-500 um emission for most lines of sight, if the long-wavelength dust emissivity scales as with 2.25. This dust model is extrapolated to predict the 2 mm dust emission. Subtraction of the model from the GISMO data provides a clearer look at the 2 mm emission of star-forming regions and the brightest nonthermal filament.
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- 2019
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4. 2 mm GISMO Observations of the Galactic Center. II. A Nonthermal Filament in the Radio Arc and Compact Sources
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Staguhn, Johannes, Arendt, Richard G, Dwek, Eli, Mark. R. Morris, Yusef-Zadeh, Farhad, Benford, Dominic J, Kovacs, Attila, and Gonzalez-Quiles, Junellie
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Astronomy - Abstract
We have used the Goddard IRAM 2 Millimeter Observer (GISMO) with the 30 m IRAM telescope to carry out a 2 mm survey of the Galaxy’s central molecular zone. These observations detect thermal emission from cold interstellar medium dust, thermal free–free emission from ionized gas, and nonthermal synchrotron emission from relatively flat-spectrum sources. Archival data sets spanning 3.6 μm–90 cm are used to distinguish different emission mechanisms. After the thermal emission of dust is modeled and subtracted, the remaining 2 mm emission is dominated by free–free emission, with the exception of the brightest nonthermal filament (NTF) that runs through the middle of the bundle of filaments known as the Radio Arc. This is the shortest wavelength at which any NTF has been detected. The GISMO observations clearly trace this NTF over a length of ∼0°. 2, with a mean 2 mm spectral index that is steeper than at longer wavelengths. The 2 mm–6 cm (or 20 cm) spectral index steepens from α ≈ −0.2 to −0.7 as a function distance from the Sickle H II region, suggesting that this region is directly related to the NTF. A number of unresolved (at 21″) 2 mm sources are found nearby. One appears to be thermal dust emission from a molecular cloud that is associated with an enigmatic radio point source whose connection to the Radio Arc is still debated. The morphology and colors at shorter IR wavelengths indicate other 2 mm unresolved sources are likely to be compact H II regions.
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- 2019
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5. The Origins Space Telescope
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Battersby, Cara, Armus, Lee, Bergin, Edwin, Kataria, Tiffany, Meixner, Margaret, Pope, Alexandra, Stevenson, Kevin B, Cooray, Asantha, Leisawitz, David, Scott, Douglas, Bauer, James, Bradford, C. Matt, Ennico, Kimberly, Fortney, Jonathan J, Kaltenegger, Lisa, Melnick, Gary J, Milam, Stefanie N, Narayanan, Desika, Padgett, Deborah, Pontoppidan, Klaus, Roellig, Thomas, Sandstrom, Karin, Su, Kate Y. L, Vieira, Joaquin, Wright, Edward, Zmuidzinas, Jonas, Staguhn, Johannes, Sheth, Kartick, Benford, Dominic, Mamajek, Eric E, Neff, Susan G, Carey, Sean, Burarella, Denis, De Beck, Elvire, Gerin, Maryvonne, Helmich, Frank P, Moseley, Harvey, Sakon, Itsuki, and Wiedner, Martinia C
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Astronomy - Abstract
The Universe has never been seen like this before. The window into the infrared opens only above Earth's atmosphere, and humanity has barely glimpsed outside. About half of the light emitted by stars, planets, and galaxies over the lifetime of the Universe emerges in the infrared. With an unparalleled sensitivity increase — up to a factor of 1,000 more than any previous or planned mission — the advance offered by the Origins Space Telescope (OST) is akin to that from the naked eye to humanity's first telescope, or from Galileo's first telescope to the first telescope in space. While key path-finding missions have glimpsed a rich infrared cosmos, extraordinary discovery space awaits; the time for a far-infrared revolution has begun.Are we alone or is life common in the Universe? OST will directly address this long-standing question by searching for signs of life in the atmospheres of potentially habitable terrestrial planets transiting M dwarf stars. How do planets become habitable? OST will trace the trail of cold water from the interstellar medium, through protoplanetary disks and into the outer reaches of our own Solar System. How do stars, galaxies, black holes and the elements of life form, from the cosmic dawn to today? With broad wavelength coverage and fast mapping speeds, OST will map millions of galaxies, simultaneously measuring star formation rates and black hole growth across cosmic time, peering deeper into the far reaches of the Universe than ever before.OST will be maintained at a temperature of 4 K, enabling its tremendous sensitivity gain, and will operate from 5 m to 600 m, encompassing the mid- and far-infrared. OST has two Mission Concepts: Concept 1 with a 9.1-m deployed off-axis primary, and Concept 2, described here, a non-deployed 5.9-m on-axis telescope with the equivalent collecting area of the James Webb Space Telescope (JWST). Concept 2 includes four instruments with capabilities for imaging (large surveys and pointed), spectroscopy (survey and high-resolution modes) and polarimetry, as well as an instrument for high-precision spectroscopy of transiting exoplanets. Concept 2 is optimized for maximum science return and minimal complexity, and offers fast mapping (approximately 60 arcseconds per second). We describe here the three key science themes for OST and the basic mission specifications.
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- 2018
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6. Overview of the Origins Space Telescope: Science Drivers to Observatory Requirements
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Meixner, Margaret, Armus, Lee, Battersby, Cara, Bauer, James, Bergin, Edwin, Cooray, Asantha, Fortney, Jonathan J, Kataria, Tiffany, Leisawitz, David T, Milam, Stefanie N, Pontoppidan, Klaus, Pope, Alexandra, Sandstrom, Karin, Staguhn, Johannes G, Stevenson, Kevin B, Su, Kate Y, Bradford, Charles Matt, Benford, Dominic, Burgarella, Denis, Carey, Sean, Carter, Ruth C, Beck, Elvire De, DiPirro, Michael J, Ennico-Smith, Kimberly, Gerin, Maryvonne, Helmich, Frank P, Kaltenegger, Lisa, Mamajek, Eric E, Melnick, Gary J, Moseley, Samuel Harvey, Narayanan, Desika, Neff, Susan G, Padgett, Deborah, Roellig, Thomas L, Sakon, Itsuki, Scott, Douglas, Sheth, Kartik, Vieira, Joaquin, Wiedner, Martina, Wright, Edward, and Zmuidzinas, Jonas
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Geosciences (General) - Abstract
e Origins Space Telescope (OST) mission concept study is the subject of one of the four science and technology definition studies supported by NASA Headquarters to prepare for the 2020 Astronomy and Astrophysics Decadal Survey. OST will survey the most distant galaxies to discern the rise of metals and dust and to unveil the co-evolution of galaxy and blackhole formation, study the Milky Way to follow the path of water from the interstellar medium to habitable worlds in planetary systems, and measure biosignatures from exoplanets. This paper describes the science drivers and how they drove key requirements for OST Mission Concept 2, which will operate between ~5 and ~600 microns with a JWST sized telescope. Mission Concept 2 for the OST study optimizes the engineering for the key science cases into a powerful and more economical observatory compared to Mission Concept 1.
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- 2018
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7. The Primordial Inflation Polarization Explorer (PIPER): Current Status and Performance of the First Flight
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Pawlyk, Samuel, Ade, Peter A. R, Benford, Dominic, Bennett, Charles L, Chuss, David T, Datta, Rahul, Dotson, Jessie L, Eimer, Joseph R, Fixsen, Dale J, Gandilo, Natalie N, Essinger-Hileman, Thomas, Halpern, Mark, Hilton, Gene, Hinshaw, Gary F, Irwin, Kent, Jhabvala, Christine, Kimball, Mark, Kogut, Alan, Lowe, Luke, McMahon, Jeff J, Miller, Timothy M, Mirel, Paul, Moseley, S. Harvey, Rodriguez, Samelys, Sharp, Elmer III, Shirron, Peter, Staguhn, Johannes G, Sullivan, Dan F, Switzer, Eric R, Taraschi, Peter, Tucker, Carole E, Walts, Alexander, and Wollack, Edward J
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Optics - Abstract
The Primordial Inflation Polarization ExploreR (PIPER) is a balloon-borne instrument optimized to measure the polarization of the CMB at large angular scales. It will map 85% of the sky over a series of conventional balloon flights from the Northern and Southern hemispheres, measuring the B-mode polarization power spectrumover a range of multipoles from 2-300 covering both the reionization bump and the recombination peak, with sensitivity to measure the tensor-to-scalar ratio down to r = 0.007. PIPER will observe in four frequency bands centered at 200, 270, 350, and 600 GHz to characterize dust foregrounds. The instrument has background-limited sensitivity provided by fully cryogenic (1.7 K) optics focusing the sky signal onto kilo-pixel arrays of time-domain multiplexed Transition-Edge Sensor (TES) bolometers held at 100 mK. Polarization sensitivity and systematiccontrol are provided by front-end Variable-delay Polarization Modulators (VPMs). PIPER had its engineering flight in October 2017 from Fort Sumner, New Mexico. This papers outlines the major components in the PIPER system discussing the conceptual design as well as specific choices made for PIPER. We also report on the results of the engineering flight, looking at the functionality of the payload systems, particularly VPM, as well as pointing out areas of improvement.
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- 2018
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8. Maturing CCD Photon-Counting Technology for Space Flight
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Mallik, Udayan, Lyon, Richard, Petrone, Peter, McElwain, Michael, Benford, Dominic, Clampin, Mark, and Hicks, Brian
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Astronomy - Abstract
This paper discusses charge blooming and starlight saturation - two potential technical problems - when using an Electron Multiplying Charge Coupled Device (EMCCD) type detector in a high-contrast instrument for imaging exoplanets. These problems especially affect an interferometric type coronagraph - coronagraphs that do not use a mask to physically block starlight in the science channel of the instrument. These problems are presented using images taken with a commercial Princeton Instrument EMCCD camera in the Goddard Space Flight Center's (GSFC), Interferometric Coronagraph facility. In addition, this paper discusses techniques to overcome such problems. This paper also discusses the development and architecture of a Field Programmable Gate Array and Digital-to-Analog Converter based shaped clock controller for a photon-counting EMCCD camera. The discussion contained here will inform high-contrast imaging groups in their work with EMCCD detectors.
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- 2015
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9. STAR Formation Histories Across the Interacting Galaxy NGC 6872, the Largest-Known Spiral
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Eufrasio, Rafael T, Dwek, E, Arendt, RIchard G, deMello, Duilia F, Gadotti, DImitri A, Urrutia-Viscarra, Fernanda, deOliveira, CLaudia Mendes, and Benford, Dominic J
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Astronomy - Abstract
NGC6872, hereafter the Condor, is a large spiral galaxy that is interacting with its closest companion, the S0 galaxy IC 4970. The extent of the Condor provides an opportunity for detailed investigation of the impact of the interaction on the current star formation rate and its history across the galaxy, on the age and spatial distribution of its stellar population, and on the mechanism that drives the star formation activity. To address these issues we analyzed the far-ultraviolet (FUV) to near-infrared (near-IR) spectral energy distribution of seventeen 10 kpc diameter regions across the galaxy, and derived their star formation history, current star formation rate, and stellar population and mass. We find that most of the star formation takes place in the extended arms, with very little star formation in the central 5 kpc of the galaxy, in contrast to what was predicted from previous numerical simulations. There is a trend of increasing star formation activity with distance from the nucleus of the galaxy, and no evidence for a recent increase in the current star formation rate due to the interaction. The nucleus itself shows no significant current star formation activity. The extent of the Condor also provides an opportunity to test the applicability of a single standard prescription for conversion of the FUV + IR (22 micrometer) intensities to a star formation rate for all regions. We find that the conversion factor differs from region to region, arising from regional differences in the stellar populations.
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- 2014
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10. The Primordial Inflation Polarization Explorer (PIPER)
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Lazear, Justin Scott, Ade, Peter A, Benford, Dominic J, Bennett, Charles L, Chuss, David T, Dotson, Jessie L, Eimer, Joseph R, Fixsen, Dale J, Halpern, Mark, Hinderks, James, Hinshaw, Gary F, Irwin, Kent, Jhabvala, Christine, Johnson, Bradley, Kogut, Alan, Lowe, Luke, McMahon, Jeff J, Miller, Timothy M, Mirel, Paul, Moseley, S. Harvey, Rodriguez, Samelys, Staguhn, Johannes G, Switzer, Eric R, Tucker, Carole E, Weston, Amy, and Wollack, Edward
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Astrophysics - Abstract
The Primordial Inflation Polarization ExploreR (Piper) is a balloon-borne cosmic microwave background (CMB) polarimeter designed to search for evidence of inflation by measuring the large-angular scale CMB polarization signal. Bicep2 recently reported a detection of B-mode power corresponding to the tensor-to-scalar ratio r = 0.2 on approximately 2 degree scales. If the Bicep2 signal is caused by inflationary gravitational waves (IGWs), then there should be a corresponding increase in B-mode power on angular scales larger than 18 degrees. Piper is currently the only suborbital instrument capable of fully testing and extending the Bicep2 results by measuring the B-mode power spectrum on angular scales theta θ = approximately 0.6 deg to 90 deg, covering both the reionization bump and recombination peak, with sensitivity to measure the tensor-to-scalar ratio down to r = 0.007, and four frequency bands to distinguish foregrounds. Piper will accomplish this by mapping 85% of the sky in four frequency bands (200, 270, 350, 600 GHz) over a series of 8 conventional balloon flights from the northern and southern hemispheres. The instrument has background-limited sensitivity provided by fully cryogenic (1.5 K) optics focusing the sky signal onto four 32×40-pixel arrays of time-domain multiplexed Transition-Edge Sensor (TES) bolometers held at 140 milli-Kelvin. Polarization sensitivity and systematic control are provided by front-end Variabledelay Polarization Modulators (VPMs), which rapidly modulate only the polarized sky signal at 3 Hz and allow Piper to instantaneously measure the full Stokes vector (I,Q,U,0V) for each pointing. We describe the Piper instrument and progress towards its first flight.
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- 2014
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11. Dust Formation, Evolution, and Obscuration Effects in the Very High-Redshift Universe
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Dwek, Eli, Staguhn, Johannes, Arendt, Richard G, Kovacs, Attila, Su, Ting, and Benford, Dominic J
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Astrophysics - Abstract
The evolution of dust at redshifts z > or approx. 9, and consequently the dust properties, differs greatly from that in the local universe. In contrast to the local universe, core collapse supernovae (CCSNe) are the only source of thermally-condensed dust. Because of the low initial dust-to-gas mass ratio, grain destruction rates are low, so that CCSNe are net producers of interstellar dust. Galaxies with large initial gas mass or high mass infall rate will therefore have a more rapid net rate of dust production comported to galaxies with lower gas mass, even at the same star formation rate. The dust composition is dominated by silicates, which exhibit a strong rise in the UV opacity near the Lyman break. This "silicate-UV break" may be confused with the Lyman break, resulting in a misidentification of a galaxies' photometric redshift. In this paper we demonstrate these effects by analyzing the spectral energy distribution (SED) of MACS1149-JD, a lensed galaxy at z = 9.6. A potential 2mm counterpart of MACS1149-JD has been identified with GISMO. While additional observations are required to corroborate this identification, we use this possible association to illustrate the physical processes and the observational effects of dust in the very high redshift universe. Subject headings: galaxies: high-redshift - galaxies: evolution - galaxies: individual (MACS1149- JD) - Interstellar medium (ISM), nebulae: dust, extinction - physical data and processes: nuclear reactions, nucleosynthesis, abundances.
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- 2014
12. Dust Formation, Evolution, and Obscuration Effects in the Very High-Redshift Universe
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Dwek, Eli, Staguhn, Johannes, Arendt, Richard G, Kovacks, Attila, Su, Ting, and Benford, Dominic J
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Astrophysics - Abstract
The evolution of dust at redshifts z > or approx. 9, and consequently the dust properties, differs greatly from that in the local universe. In contrast to the local universe, core collapse supernovae (CCSNe) are the only source of thermally-condensed dust. Because of the low initial dust-togas mass ratio, grain destruction rates are low, so that CCSNe are net producers of interstellar dust. Galaxies with large initial gas mass or high mass infall rate will therefore have a more rapid net rate of dust production comported to galaxies with lower gas mass, even at the same star formation rate. The dust composition is dominated by silicates, which exhibit a strong rise in the UV opacity near the Lyman break. This "silicate-UV break" may be confused with the Lyman break, resulting in a misidentification of a galaxies' photometric redshift. In this paper we demonstrate these effects by analyzing the spectral energy distribution (SED) of MACS1149-JD, a lensed galaxy at z = 9.6. A potential 2mm counterpart of MACS1149-JD has been identified with GISMO. While additional observations are required to corroborate this identification, we use this possible association to illustrate the physical processes and the observational effects of dust in the very high redshift universe.
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- 2014
13. Design and Expected Performance of GISMO-2, a Two Color Millimeter Camera for the IRAM 30 m Telescope
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Staguhn, Johannes G, Benford, Dominic J, Dwek, Eli, Hilton, Gene, Fixsen, Dale J, Irwin, Kent, Jhabvala, Christine, Kovacs, Attila, Leclercq, Samuel, Maher, Stephen F, Miller, Tim, Moseley, S. Harvey, Sharp, Elmer H, and Wollack, Edward
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Astronomy ,Instrumentation And Photography - Abstract
We present the main design features for the GISMO-2 bolometer camera, which we build for background-limited operation at the IRAM 30 m telescope on Pico Veleta, Spain. GISMO-2 will operate simultaneously in the 1 and 2 mm atmospherical windows. The 1 mm channel uses a 32 × 40 TES-based backshort under grid (BUG) bolometer array, the 2 mm channel operates with a 16 × 16 BUG array. The camera utilizes almost the entire full field of view provided by the telescope. The optical design of GISMO-2 was strongly influenced by our experience with the GISMO 2mm bolometer camera, which is successfully operating at the 30 m telescope. GISMO is accessible to the astronomical community through the regularIRAMcall for proposals.
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- 2014
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14. Erratum: Wise Detections of Known Qsos at Redshifts Greater than Six
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Blain, Andrew W, Assef, Roberto, Stern, Daniel K, Tsai, Chao-Wei, Eisenhardt, Peter, Bridge, Carrie, Benford, Dominic J, Jarrett, Tom, Cutri, Roc, Petty, Sara, Wu, Jingwen, and Wright, Edward L
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Astrophysics ,Astronomy - Abstract
In the published version of this paper, Roberto Assef was mistakenly affiliated with the Division of Astronomy and Astrophysics at the University of California, Los Angeles. This is incorrect. Dr. Assef's affiliation correctly appears in this erratum as the Nucleo de Astronomıa de la Facultad de Ingenierıa, Universidad Diego Portales, Av. Ejercito 441, Santiago, Chile. IOP Publishing sincerely regrets this error.
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- 2014
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15. Scientific Objectives for UV-Visible Astrophysics Investigations: A Summary of Responses by the Community (2012)
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Scowen, Paul A, Perez, Mario R, Neff, Susan G, and Benford, Dominic J
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Astronomy ,Astrophysics - Abstract
Following several recommendations presented by the Astrophysics Decadal Survey 2010 centered around the need to define "a future ultraviolet-optical space capability," on 2012 May 25, NASA issued a Request for Information (RFI) seeking persuasive ultraviolet (UV) and visible wavelength astrophysics science investigations. The goal was to develop a cohesive and compelling set of science objectives that motivate and support the development of the next generation of ultraviolet/visible space astrophysics missions. Responses were due on 10 August 2012 when 34 submissions were received addressing a number of potential science drivers. A UV/visible Mission RFI Workshop was held on 2012 September 20 where each of these submissions was summarized and discussed in the context of each other. We present a scientific analysis of these submissions and presentations and the pursuant measurement capability needs, which could influence ultraviolet/visible technology development plans for the rest of this decade. We also describe the process and requirements leading to the inception of this community RFI, subsequent workshop and the expected evolution of these ideas and concepts for the remainder of this decade.
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- 2014
16. WISE Discovery of Hyper Luminous Galaxies at z=2-4 and Their Implications for Galaxy and AGN Evolution
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Tsai, Chao Wei, Eisenhardt, Peter, Wu, Jingwen, Bridge, Carrie, Assef, Roberto, Benford, Dominic, Blain, Andrew, Cutri, Roc, Griffith, Robert L, Jarrett, Thomas, Lonsdale, Carol, Petty, Sara, Sayers, Jack, Stanford, Adam, Stern, Daniel, Wright, Edward L, and Yan, Lin
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Astrophysics - Abstract
On behalf of the WISE Science team, we present the discovery of a class of distant dust-enshrouded galaxies with extremely high luminosity. These galaxies are selected to have extreme red colors in the mid-IR using NASA's Wide-field Infrared Survey Explorer (WISE). They are faint in the optical and near-IR, predominantly at zeta = 2-4, and with IR luminosity > 10(exp 13) Solar Luminosity, making them Hyper-Luminous Infrared Galaxies (HyLIRGs). SEDs incorporating the WISE, Spitzer, and Herschel PACS and SPIRE photometry indicate hot dust dominates the bolometric luminosity, presumably powered by AGN. Preliminary multi-wavelength follow-up suggests that they are different from normal populations in the local M-sigma relation. Their low source density implies that these objects are either intrinsically rare, or a short-lived phase in a more numerous population. If the latter is the case, these hot, dust-enshrouded galaxies may be an early stage in the interplay between AGN and galaxies.
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- 2014
17. Scientific Objectives for UV-Visible Astrophysics Investigations: A Summary of Responses by the Community (2012)
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Scowen, Paul A, Perez, Mario R, Neff, Susan G, and Benford, Dominic J
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Astrophysics - Abstract
Following several recommendations presented by the Astrophysics Decadal Survey 2010 centered around the need to define "a future ultraviolet-optical space capability," on 2012 May 25, NASA issued a Request for Information (RFI) seeking persuasive ultraviolet (UV) and visible wavelength astrophysics science investigations. The goal was to develop a cohesive and compelling set of science objectives that motivate and support the development of the next generation of ultraviolet/visible space astrophysics missions. Responses were due on 10 August 2012 when 34 submissions were received addressing a number of potential science drivers. A UV/visible Mission RFI Workshop was held on 2012 September 20 where each of these submissions was summarized and discussed in the context of each other. We present a scientific analysis of these submissions and presentations and the pursuant measurement capability needs, which could influence ultraviolet/visible technology development plans for the rest of this decade. We also describe the process and requirements leading to the inception of this community RFI, subsequent workshop and the expected evolution of these ideas and concepts for the remainder of this decade.
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- 2013
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18. Wise Detections of Known QSOS at Redshifts Greater Than Six
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Blain, Andrew W, Assef, Roberto, Stern, Daniel, Tsai, Chao-Wei, Eisenhardt, Peter, Bridge, Carrie, Benford, Dominic, Jarrett, Tom, Cutri, Roc, Petty, Sara, Wu, Jingwen, and Wright, Edward L
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Astrophysics ,Astronomy - Abstract
We present WISE All-Sky mid-infrared (IR) survey detections of 55 % (17/31) of the known QSOs at z greater than 6 from a range of surveys: the SDSS, the CFHT-LS, FIRST, Spitzer and UK1DSS. The WISE catalog thus provides a substantial increase in tiie quantity of IR data available for these sources: 17 are detected in the WISE Wl (3.4 micrometer) band, 16 in W2 (4.6 micrometers), 3 in W3 (12 micrometers) and 0 in W4 (22micrometers). This is particularly important with Spitzer in its warm-mission phase and no faint follow-up capability at wavelengths longwards of 5 micrometers until the launch of JWST. WISE thus provides a useful tool for understanding QSOs found in forthcoming large-area optical/IR sky surveys, using PanSTARRS, SkyMapper, VISTA, DES and LSST. The rest-UV properties of the WISE-detected and the WISE-non-detected samples differ: the detections have brighter i/z-band magnitudes and redder rest-UV colors. This suggests thai a more aggressive hunt for very-high-redshift QSOs, by combining WISE Wl and W2 data with red observed optical colors could be effective at least, for a subset of dusty candidate QSOs. Stacking the WISE images of the WISE-non-detected QSOs indicates that they are on average significantly fainter than the WISE-detccted examples, and are thus not narrowly missing detection in the WISE catalog. The WISE-catalog detection of three of our sample in the W3 band indicates that their mid-ID flux can be detected individually, although there is no stacked W3 detection of sources detected in Wl but not. W3. Stacking analyses of WISE data for large AGN samples will be a useful tool, and high-redshifl. QSOs of all types will be easy targets for JWST.
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- 2013
19. WISE J233237.05-505643.5: A Double-Peaked Broad-Lined AGN with Spiral-Shaped Radio Morphology
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Tsai, Chao Wei, Jarrett, Thomas H, Stern, Daniel, Emonts, Bjorn, Barrows, R. Scott, Assef, Roberto J, Norris, Ray P, Eisenhardt, Peter R. M, Lonsdale, Carol, Blain, Andrew W, Benford, Dominic J, Wu, Jingwen, Stalder, Brian, Stubbs, Christopher W, High, F. William, Li, K. L, and Kong, Albert K. H
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Astronomy ,Astrophysics - Abstract
We present radio continuum mapping, optical imaging and spectroscopy of the newly discovered double-peaked broad-lined AGN WISE J233237.05-505643.5 at redshift z = 0.3447. This source exhibits an FR-I and FR-II hybrid-morphology, characterized by bright core, jet, and Doppler-boosted lobe structures in ATCA continuum maps at 1.5, 5.6, and 9 GHz. Unlike most FR-II objects, W2332-5056 is hosted by a disk-like galaxy. The core has a projected 5" linear radio feature that is perpendicular to the curved primary jet, hinting at unusual and complex activity within the inner 25 kpc. The multi-epoch optical-near-IR photometric measurements indicate significant variability over a 3-20 year baseline from the AGN component. Gemini-South optical data shows an unusual double-peaked emission-line features: the centroids of the broad-lined components of H-alpha and H-beta are blueshifted with respect to the narrow lines and host galaxy by approximately 3800 km/s. We examine possible cases which involve single or double supermassive black holes in the system, and discuss required future investigations to disentangle the mystery nature of this system.
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- 2013
20. Submillimeter Follow-up of Wise-Selected Hyperluminous Galaxies
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Wu, Jingwen, Tsai, Chao-Wei, Sayers, Jack, Benford, Dominic, Bridge, Carrie, Blain, Andrew, Eisenhardt, Peter R. M, Stern, Daniel, Petty, Sara, Assef, Roberto, Bussmann, Shane, Comerford, Julia M, Cutri, Roc, Evans, Neal J., II, Griffith, Roger, Jarrett, Thomas, Lake, Sean, Lonsdale, Carol, Rho, Jeonghee, and Stanford, S. Adam
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Astrophysics - Abstract
We have used the Caltech Submillimeter Observatory (CSO) to follow-up a sample of Wide-field Infrared Survey Explorer (WISE) selected, hyperluminous galaxies, the so-called W1W2-dropout galaxies. This is a rare (approximately 1000 all-sky) population of galaxies at high redshift (peaks at zeta = 2-3), which are faint or undetected by WISE at 3.4 and 4.6 micrometers, yet are clearly detected at 12 and 22 micrometers. The optical spectra of most of these galaxies show significant active galactic nucleus activity. We observed 14 high-redshift (zeta greater than 1.7) W1W2-dropout galaxies with SHARC-II at 350-850 micrometers, with nine detections, and observed 18 with Bolocam at 1.1 mm, with five detections. Warm Spitzer follow-up of 25 targets at 3.6 and 4.5 micrometers, as well as optical spectra of 12 targets, are also presented in the paper. Combining WISE data with observations from warm Spitzer and CSO, we constructed their mid-IR to millimeter spectral energy distributions (SEDs). These SEDs have a consistent shape, showing significantly higher mid-IR to submillimeter ratios than other galaxy templates, suggesting a hotter dust temperature.We estimate their dust temperatures to be 60-120 K using a single-temperature model. Their infrared luminosities are well over 10(exp 13) solar luminosity. These SEDs are not well fitted with existing galaxy templates, suggesting they are a new population with very high luminosity and hot dust. They are likely among the most luminous galaxies in the universe.We argue that they are extreme cases of luminous, hot dust-obscured galaxies (DOGs), possibly representing a short evolutionary phase during galaxy merging and evolution. A better understanding of their long-wavelength properties needs ALMA as well as Herschel data.
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- 2013
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21. A New Population of High-z, Dusty Lyman-alpha Emitters and Blobs Discovered by WISE: Feedback Caught in the Act?
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Bridge, Carrie R, Blain, Andrew, Borys, Colin J. K, Petty, Sara, Benford, Dominic, Eisenhardt, Peter, Farrah, Duncan, Griffith, Roger, L, Jarrett, Tom, Lonsdale, Carol, Stanford. Spencer A, Stern, Daniel, Tsai, Chao-Wei, Wright, Edward L, and Wu, Jingwen
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Astrophysics - Abstract
By combining data from the NASA Wide-field Infrared Survey Explorer (WISE) mission with optical spectroscopy from the W. M. Keck telescope, we discover a mid-IR color criterion that yields a 78% success rate in identifying rare, typically radio-quiet, 1.6 approx. < z approx. < 4.6 dusty Ly-alpha emitters (LAEs). Of these, at least 37% have emission extended on scales of 30-100 kpc and are considered Ly-alpha "blobs" (LABs). The objects have a surface density of only approx.. 0.1 deg(exp -2), making them rare enough that they have been largely missed in deep, small area surveys. We measured spectroscopic redshifts for 92 of these galaxies, and find that the LAEs (LABs) have a median redshift of 2.3 (2.5). The WISE photometry coupled with data from Herschel (Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA) reveals that these galaxies are in the Hyper Luminous IR galaxy regime (L(sub IR) approx. > 10(exp 13)-10(exp 14) Solar L) and have warm colors. They are typically more luminous and warmer than other dusty, z approx.. 2 populations such as submillimeter-selected galaxies and dust-obscured galaxies. These traits are commonly associated with the dust being illuminated by intense active galactic nucleus activity. We hypothesize that the combination of spatially extended Ly-alpha, large amounts of warm IR-luminous dust, and rarity (implying a short-lived phase) can be explained if the galaxies are undergoing brief, intense "feedback" transforming them from an extreme dusty starburst/QSO into a mature galaxy.
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- 2013
- Full Text
- View/download PDF
22. UV/Visible Telescope with Hubble Disposal
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Benford, Dominic J
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Astrophysics - Abstract
Submission Overview: Our primary objective is to convey a sense of the significant advances possible in astrophysics investigations for major Cosmic Origins COR program goals with a 2.4m telescope asset outfitted with one or more advanced UV visible instruments. Several compelling science objectives were identified based on community meetings these science objectives drove the conceptual design of instruments studied by the COR Program Office during July September 2012. This RFI submission encapsulates the results of that study, and suggests that a more detailed look into the instrument suite should be conducted to prove viability and affordability to support the demonstrated scientific value. This study was conducted in the context of a larger effort to consider the options available for a mission to dispose safely of Hubble hence, the overall architecture considered for the mission we studied for the 2.4m telescope asset included resource sharing. This mitigates combined cost and risk and provides naturally for a continued US leadership role in astrophysics with an advanced, general-purpose UV visible space telescope.
- Published
- 2013
23. Spitzer Photometry of WISE-Selected Brown Dwarf and Hyper-Lumninous Infrared Galaxy Candidates
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Griffith, Roger L, Kirkpatrick, J. Davy, Eisenhardt, Peter R. M, Gelino, Christopher R, Cushing, Michael C, Benford, Dominic, Blain, Andrew, Bridge, Carrie R, Cohen, Martin, Cutri, Roc M, Donoso, Emilio, Jarrett, Thomas H, Lonsdale, Carol, Mace, Gregory, Mainzer, A, Marsh, Ken, Padgett, Deborah, Petty, Sara, Ressler, Michael E, Skrutskie, Michael F, Stanford, Spencer A, Stern, Daniel, Tsai, Chao-Wei, Wright, Edward L, and Wu, Jingwen
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Astronomy - Abstract
We present Spitzer 3.6 and 4.5 micrometer photometry and positions for a sample of 1510 brown dwarf candidates identified by the Wide-field Infrared Survey Explorer (WISE) all-sky survey. Of these, 166 have been spectroscopically classified as objects with spectral types M(1), L(7), T(146), and Y(12). Sixteen other objects are non-(sub)stellar in nature. The remainder are most likely distant L and T dwarfs lacking spectroscopic verification, other Y dwarf candidates still awaiting follow-up, and assorted other objects whose Spitzer photometry reveals them to be background sources. We present a catalog of Spitzer photometry for all astrophysical sources identified in these fields and use this catalog to identify seven fainter (4.5 m to approximately 17.0 mag) brown dwarf candidates, which are possibly wide-field companions to the original WISE sources. To test this hypothesis, we use a sample of 919 Spitzer observations around WISE-selected high-redshift hyper-luminous infrared galaxy candidates. For this control sample, we find another six brown dwarf candidates, suggesting that the seven companion candidates are not physically associated. In fact, only one of these seven Spitzer brown dwarf candidates has a photometric distance estimate consistent with being a companion to the WISE brown dwarf candidate. Other than this, there is no evidence for any widely separated (greater than 20 AU) ultra-cool binaries. As an adjunct to this paper, we make available a source catalog of 7.33 x 10(exp 5) objects detected in all of these Spitzer follow-up fields for use by the astronomical community. The complete catalog includes the Spitzer 3.6 and 4.5 m photometry, along with positionally matched B and R photometry from USNO-B; J, H, and Ks photometry from Two Micron All-Sky Survey; and W1, W2, W3, and W4 photometry from the WISE all-sky catalog.
- Published
- 2012
- Full Text
- View/download PDF
24. Scientific Objectives for UV/Visible Astrophysics Investigations: A Summary of Responses by the Community (2012)
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Scowen, Paul, Perez, Mario R, Neff, Susan G, and Benford, Dominic J
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Astrophysics - Abstract
Following several recommendations presented by the Astrophysics Decadal Survey 2010 centered around the need to define "a future ultraviolet-optical space capability," on 2012 May 25, NASA issued a Request for Information (RFI) seeking persuasive ultraviolet (UV) and visible wavelength astrophysics science investigations. The goal was to develop a cohesive and compelling set of science objectives that motivate and support the development of the next generation of ultraviolet/visible space astrophysics missions. Responses were due on 10 August 2012 when 34 submissions were received addressing a number of potential science drivers. A UV/visible Mission RFI Workshop was held on 2012 September 20 where each of these submissions was summarized and discussed in the context of each other. We present a scientific analysis of these submissions and presentations and the pursuant measurement capability needs, which could influence ultraviolet/visible technology development plans for the rest of this decade. We also describe the process and requirements leading to the inception of this community RFI, subsequent workshop and the expected evolution of these ideas and concepts for the remainder of this decade.
- Published
- 2012
25. Submillimeter Follow-Up of WISE-Selected Hyperluminous Galaxies
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Wu, Jingwen, Tsai, Chao-Wei, Sayers, Jack, Benford, Dominic, Bridge, Carrie, Blain, Andrew, Eisenhardt, Peter R, Stern, Daniel, Petty, Sara, Assef, Roberto, Bussmann, Shane, Comerford, Julia M, Cutri, Roc, Evans, Neal J., II, Griffith, Roger, Jarrett, Thomas, Lake, Sean, Lonsdale, Carol, Rho, Jeonghee, Stanford, S. Adam, Weiner, Benjamin, Wright, Edward L, and Yan, Lin
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Astronomy - Abstract
We have used the Caltech Submillimeter Observatory (CSO) to follow-up a sample of Wide-field Infrared Survey Explorer (WISE) selected, hyperluminous galaxies, the so-called W1W2-dropout galaxies. This is a rare (approx.1000 all-sky) population of galaxies at high redshift (peaks at z = 2-3), which are faint or undetected by WISE at 3.4 and 4.6 microns, yet are clearly detected at 12 and 22 microns. The optical spectra of most of these galaxies show significant active galactic nucleus activity. We observed 14 high-redshift (z > 1.7) W1W2-dropout galaxies with SHARC-II at 350-850 microns, with nine detections, and observed 18 with Bolocam at 1.1 mm, with five detections. Warm Spitzer follow-up of 25 targets at 3.6 and 4.5 microns, as well as optical spectra of 12 targets, are also presented in the paper. Combining WISE data with observations from warm Spitzer and CSO, we constructed their mid-IR to millimeter spectral energy distributions (SEDs). These SEDs have a consistent shape, showing significantly higher mid-IR to submillimeter ratios than other galaxy templates, suggesting a hotter dust temperature.We estimate their dust temperatures to be 60 C120 K using a single-temperature model. Their infrared luminosities are well over 10(exp 13) Stellar Luminosity. These SEDs are not well fitted with existing galaxy templates, suggesting they are a new population with very high luminosity and hot dust. They are likely among the most luminous galaxies in the universe.We argue that they are extreme cases of luminous, hot dust-obscured galaxies (DOGs), possibly representing a short evolutionary phase during galaxy merging and evolution. A better understanding of their long-wavelength properties needs ALMA as well as Herschel data.
- Published
- 2012
- Full Text
- View/download PDF
26. The First Hyper-Luminous Infrared Galaxy Discovered by WISE
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Eisenhardt, Peter R, Wu, Jingwen, Tsai, Chao-Wei, Assef, Roberto, Benford, Dominic, Blain, Andrew, Bridge, Carrie, Condon, J. J, Cushing, Michael C, Cutri, Roc, Evans, Neal J., III, Gelino, Chris, Griffith, Roger L, Grillmair, Carl J, Jarrett, Tom, Lonsdale, Carol J, Masci, Frank J, Mason, Brian S, Petty, Sara, Sayers, Jack, Stanford, S. Adam, Stern, Daniel, Wright, Edward L, and Yan, Lin
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Astrophysics - Abstract
We report the discovery by the Wide-field Infrared Survey Explorer of the z = 2.452 source WISEJ181417.29+341224.9, the first hyperluminous source found in the WISE survey. WISE 1814+3412 is also the prototype for an all-sky sample of approximately 1000 extremely luminous "W1W2-dropouts" (sources faint or undetected by WISE at 3.4 and 4.6 micrometers and well detected at 12 or 22 micrometers). The WISE data and a 350 micrometers detection give a minimum bolometric luminosity of 3.7 x 10(exp 13) solar luminosity, with approximately 10(exp 14) solar luminosity plausible. Followup images reveal four nearby sources: a QSO and two Lyman Break Galaxies (LBGs) at z = 2.45, and an M dwarf star. The brighter LBG dominates the bolometric emission. Gravitational lensing is unlikely given the source locations and their different spectra and colors. The dominant LBG spectrum indicates a star formation rate approximately 300 solar mass yr(exp -1), accounting for less than or equal to 10 percent of the bolometric luminosity. Strong 22 micrometer emission relative to 350 micrometer implies that warm dust contributes significantly to the luminosity, while cooler dust normally associated with starbursts is constrained by an upper limit at 1.1 mm. Radio emission is approximately 10? above the far-infrared/radio correlation, indicating an active galactic nucleus is present. An obscured AGN combined with starburst and evolved stellar components can account for the observations. If the black hole mass follows the local MBH-bulge mass relation, the implied Eddington ratio is approximately greater than 4. WISE 1814+3412 may be a heavily obscured object where the peak AGN activity occurred prior to the peak era of star formation.
- Published
- 2012
27. ACCESS: Design and Sub-System Performance
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Kaiser, Mary Elizabeth, Morris, Matthew J, McCandliss, Stephan R, Rasucher, Bernard J, Kimble, Randy A, Kruk, Jeffrey W, Pelton, Russell, Mott, D. Brent, Wen, Hiting, Foltz, Roger, Quijada, Manuel A, Gum, Jeffery S, Gardner, Jonathan P, Kahle, Duncan M, Benford, Dominic J, Woodgate, Bruce E, Wright, Edward L, Feldman, Paul D, Hart, Murdock, Moos, H. Warren, Reiss, Adam G, Bohlin, Ralph, Deustua, Susana E, Dixon, W. V, and Sahnow, David J
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Astrophysics - Abstract
Establishing improved spectrophotometric standards is important for a broad range of missions and is relevant to many astrophysical problems. ACCESS, "Absolute Color Calibration Experiment for Standard Stars", is a series of rocket-borne sub-orbital missions and ground-based experiments designed to enable improvements in the precision of the astrophysical flux scale through the transfer of absolute laboratory detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 -1.7 micrometer bandpass.
- Published
- 2012
28. Enabling Large Focal Plane Arrays Through Mosaic Hybridization
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Miller, Timothy M, Jhabvala, Christine A, Leong, Edward, Costen, Nicholas P, Sharp, Elmer, Adachi, Tomoko, and Benford, Dominic J
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Electronics And Electrical Engineering - Abstract
We have demonstrated advances in mosaic hybridization that will enable very large format far-infrared detectors. Specifically we have produced electrical detector models via mosaic hybridization yielding superconducting circuit paths by hybridizing separately fabricated sub-units onto a single detector unit. The detector model was made on a 100mm diameter wafer while four model readout quadrant chips were made from a separate 100mm wafer. The individually fabricated parts were hybridized using a flip-chip bonder to assemble the detector-readout stack. Once all of the hybridized readouts were in place, a single, large and thick silicon substrate was placed on the stack and attached with permanent epoxy to provide strength and a Coefficient of Thermal Expansion match to the silicon components underneath. Wirebond pads on the readout chips connect circuits to warm readout electronics; and were used to validate the successful superconducting electrical interconnection of the model mosaic-hybrid detector. This demonstration is directly scalable to 150 mm diameter wafers, enabling pixel areas over ten times the area currently available.
- Published
- 2012
29. The GISMO-2 Bolometer Camera
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Staguhn, Johannes G, Benford, Dominic J, Fixsen, Dale J, Hilton, Gene, Irwin, Kent D, Jhabvala, Christine A, Kovacs, Attila, Leclercq, Samuel, Maher, Stephen F, Miller, Timothy M, Moseley, Samuel H, Sharp, Elemer H, and Wollack, Edward J
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Instrumentation And Photography - Abstract
We present the concept for the GISMO-2 bolometer camera) which we build for background-limited operation at the IRAM 30 m telescope on Pico Veleta, Spain. GISM0-2 will operate Simultaneously in the 1 mm and 2 mm atmospherical windows. The 1 mm channel uses a 32 x 40 TES-based Backshort Under Grid (BUG) bolometer array, the 2 mm channel operates with a 16 x 16 BUG array. The camera utilizes almost the entire full field of view provided by the telescope. The optical design of GISM0-2 was strongly influenced by our experience with the GISMO 2 mm bolometer camera which is successfully operating at the 30m telescope. GISMO is accessible to the astronomical community through the regular IRAM call for proposals.
- Published
- 2012
30. Enabling Large Focal Plane Arrays Through Mosaic Hybridization
- Author
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Miller, TImothy M, Jhabvala, Christine A, Leong, Edward, Costen, Nicholas P, Sharp, Elmer, Adachi, Tomoko, and Benford, Dominic
- Subjects
Electronics And Electrical Engineering - Abstract
We have demonstrated advances in mosaic hybridization that will enable very large format far-infrared detectors. Specifically we have produced electrical detector models via mosaic hybridization yielding superconducting circuit paths by hybridizing separately fabricated sub-units onto a single detector unit. The detector model was made on a 100mm diameter wafer while four model readout quadrant chips were made from a separate 100mm wafer. The individually fabricated parts were hybridized using a flip-chip bonder to assemble the detector-readout stack. Once all of the hybridized readouts were in place, a single, large and thick silicon substrate was placed on the stack and attached with permanent epoxy to provide strength and a Coefficient of Thermal Expansion match to the silicon components underneath. Wirebond pads on the readout chips connect circuits to warm readout electronics; and were used to validate the successful superconducting electrical interconnection of the model mosaic-hybrid detector. This demonstration is directly scalable to 150 mm diameter wafers, enabling pixel areas over ten times the area currently available.
- Published
- 2012
31. Enabling Large Focal Plane Arrays Through Mosaic Hybridization
- Author
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Miller, Timothy M, Jhabvala, Christine A, Leong, Edward, Costen, Nick P, Sharp, Elmer, Adachi, Tomoko, and Benford, Dominic J
- Subjects
Instrumentation And Photography - Abstract
We have demonstrated advances in mosaic hybridization that will enable very large format far-infrared detectors. Specifically we have produced electrical detector models via mosaic hybridization yielding superconducting circuit patbs by hybridizing separately fabricated sub-units onto a single detector unit. The detector model was made on a 100mm diameter wafer while four model readout quadrant chips were made from a separate 100mm wafer. The individually fabric.ted parts were hybridized using a Suss FCI50 flip chip bonder to assemble the detector-readout stack. Once all of the hybridized readouts were in place, a single, large and thick silicon substrate was placed on the stack and attached with permanent epoxy to provide strength and a Coefficient of Thermal Expansion match to the silicon components underneath. Wirebond pads on the readout chips connect circuits to warm readout electronics; and were used to validate the successful superconducting electrical interconnection of the model mosaic-hybrid detector. This demonstration is directly scalable to 150 mm diameter wafers, enabling pixel areas over ten times the area currently available.
- Published
- 2012
32. Multicolor Detectors for Ultrasensitive Long-Wave Imaging Cameras
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Brown, Ari, Benford, Dominic, Chervenak, James, and Wollack, Edward
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Man/System Technology And Life Support - Abstract
A document describes a zeptobolometer for ultrasensitive, long-wavelength sensors. GSFC is developing pixels based on the zeptobolometer design that sense three THz wavelengths simultaneously. Two innovations are described in the document: (1) a quasiparticle (QO) filter arrangement that enables a compact multicolor spectrum at the focal plane, and (2) a THz antenna readout by up to three bolometers. The innovations enable high efficiency by greatly reducing high, frequency-dependent microstrip losses, and pixel compactness by eliminating the need for bulky filters in the focal plane. The zeptobolometer is a small TES bolometer, on the scale of a few microns, which can be readily coupled through an impedance-matching resistor to a metal or dielectric antenna. The bolometer is voltage-biased in its superconducting transition, allowing the use of superconducting RF multiplexers to read out large arrays. The antenna is geometrically tapped at three locations so as to efficiently couple radiation of three distinct wavelengths to the individual TESs. The transition edge hot electrons in metals offer a simple, compact arrangement for antenna readout, which can be crucial in the THz where line losses at high frequencies can be substantial. A metallic grill filter acts as a high-pass filter and directs the low-frequency components to a location where they will be absorbed. The absorption spectrum shows that three well-separated THz bands are feasible. The filters can be made from high-purity dielectrics such as float zone silicon or sapphire.
- Published
- 2012
33. SGAS 143845.1 + 145407: A Big, Cool Starburst at Redshift 0.816
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Gladders, Michael D, Rigby, Jane R, Sharon, Keren, Wuyts, Eva, Abramson, Louis E, Dahle, Hakon, Persson, S. E, Monson, Andrew J, Kelson, Daniel D, Benford, Dominic J, Murphy, David, Bayliss, Matthew B, Finkelstein, Keely D, Koester, Benjamin P, Bans, Alissa, Baxter, Eric J, and Helsby, Jennifer E
- Subjects
Astronomy - Abstract
We present the discovery and a detailed multi-wavelength study of a strongly-lensed luminous infrared galaxy at z=0.816. Unlike most known lensed galaxies discovered at optical or near-infrared wavelengths, this lensed source is red, which the data presented here demonstrate is due to ongoing dusty star formation. The overall lensing magnification (a factor of 17) facilitates observations from the blue optical through to 500 micrometers, fully capturing both the stellar photospheric emission as well as the reprocessed thermal dust emission. We also present optical and near-IR spectroscopy. These extensive data show that this lensed galaxy is in many ways typical of IR-detected sources at z approximates 1, with both a total luminosity and size in accordance with other (albeit much less detailed) measurements in samples of galaxies observed in deep fields with the Spitzer telescope. Its far-infrared spectral energy distribution is well-fit by local templates that are an order of magnitude less luminous than the lensed galaxy; local templates of comparable luminosity are too hot to fit. Its size (D approximately 7 kpc) is much larger than local luminous infrared galaxies, but in line with sizes observed for such galaxies at z approximates 1. The star formation appears uniform across this spatial scale. Thus, this lensed galaxy, which appears representative of vigorously star-forming z approximates 1 galaxies, is forming stars in a fundamentally different mode than is seen at z approximates 0.
- Published
- 2012
34. The Infrared Properties of Sources Matched in the Wise All-Sky and Herschel ATLAS Surveys
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Bond, Nicholas A, Benford, Dominic J, Gardner, Jonathan P, Amblard, Alexandre, Fleuren, Simone, Blain, Andrew W, Dunne, Loretta, Smith, Daniel J. B, Maddox, Steve J, Hoyos, Carlos, Auld, Robbie, Bales, Maarten, Bonfield, David, Bourne, Nathan, Bridge, Carrie, Buttiglione, Sara, Cava, Antonio, Clements, David, Cooray, Asantha, Dariush, Ali, deZotti, Gianfranco, Driver, Simon, Tsai, Chao-Wei, Wright, Edward L, and Yan, Lin
- Subjects
Astrophysics - Abstract
We describe the infrared properties of sources detected over approx 36 sq deg of sky in the GAMA 15-hr equatorial field, using data from both the Herschel Astrophysical Terahertz Large-Area Survey (HATLAS) and Wide-field Infrared Survey (WISE). With 5sigma point-source depths of 34 and 0.048 mJy at 250 micron and 3.4 micron, respectively, we are able to identify 50.6% of the H-ATLAS sources in the WISE survey, corresponding to a surface density of approx 630 deg(exp -2). Approximately two-thirds of these sources have measured spectroscopic or optical/near-IR photometric redshifts of z < 1. For sources with spectroscopic redshifts at z < 0.3, we find a linear correlation between the infrared luminosity at 3.4 micron and that at 250 micron, with +/- 50% scatter over approx 1.5 orders of magnitude in luminosity, approx 10(exp 9) - 10(exp 10.5) Solar Luminosity By contrast, the matched sources without previously measured redshifts (r approx > 20.5) have 250-350 micron flux density ratios that suggest either high-redshift galaxies (z approx > 1.5) or optically faint low-redshift galaxies with unusually low temperatures (T approx < 20). Their small 3.4-250 micron flux ratios favor a high-redshift galaxy population, as only the most actively star-forming galaxies at low redshift (e.g., Arp 220) exhibit comparable flux density ratios. Furthermore, we find a relatively large AGN fraction (approx 30%) in a 12 micron flux-limited subsample of H-ATLAS sources, also consistent with there being a significant population of high-redshift sources in the no-redshift sample
- Published
- 2012
35. US Instrument Options for the SPICA Observatory
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Benford, Dominic, Carter, Ruth, Benner, Steve, Rossetti, Dino, Leete, Stephen, Townsend, Jackie, Keer, Beth, and Davis, Chris
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Instrumentation And Photography - Abstract
NASA has engaged in studying options for a US contribution to the Japanese-led Space II Astrophysics (SPICA). This cryogenic 3m-class telescope builds on the scientific and technological legacies of Akari and Hershel. The primary portion of a US contribution would be a far-infrared spectrometer, but with a sensitivity several hundred times greater than Herschel, opening up this wavelength range for study of emission lines from galaxies up to the highest redshifts. We describe efforts to formulate an approach that fits within project and programmatic constraints and fulfills the scientific promise of the SPICA observatory.
- Published
- 2012
36. The Infrared Properties of Sources Matched in the WISE All-Sky and Herschel Atlas Surveys
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Bond, Nicholas A, Benford, Dominic J, Gardner, Jonathan P, Eisenhardt, Peter, Amblard, Alexandre, Temi, Pasquale, Fleuren, Simone, Blain, Andrew W, Dunne, Loretta, Smith, Daniel J, Maddox, Steve J, Hoyos, Carlos, Dye, Simon, Baes, Maarten, Bonfield, David, Bourne, Nathan, and Bridge,Carrie
- Subjects
Astrophysics - Abstract
We describe the infrared properties of sources detected over approx. 36 deg2 of sky in the GAMA 15-hr equatorial field, using data from both the Herschel Astrophysical Terahertz Large-Area Survey (H-ATLAS) and Wide-field Infrared Survey (WISE). With 5(sigma) point-source depths of 34 and 0.048 mJy at 250 microns and 3.4 microns, respectively, we are able to identify 50.6% of the H-ATLAS sources in the WISE survey, corresponding to a surface density of approx. 630 deg-2. Approximately two-thirds of these sources have measured spectroscopic or optical/near-IR photometric redshifts of z < 1. For sources with spectroscopic redshifts at z < 0.3, we find a linear correlation between the infrared luminosity at 3.4 microns and that at 250 microns, with +/-50% scatter over approx. 1.5 orders of magnitude in luminosity, approx. 10(exp 9) - 10(exp 10.5) Stellar Luminosity. By contrast, the matched sources without previously measured redshifts (r > or approx. 20.5) have 250-350 microns flux density ratios that suggest either high-redshift galaxies (z > or approx. 1.5) or optically faint low-redshift galaxies with unusually low temperatures (T < or approx. 20). Their small 3.4-250 microns flux ratios favor a high-redshift galaxy population, as only the most actively star-forming galaxies at low redshift (e.g., Arp 220) exhibit comparable flux density ratios. Furthermore, we find a relatively large AGN fraction (approx. 30%) in a 12 microns flux-limited subsample of H-ATLAS sources, also consistent with there being a significant population of high-redshift sources in the no-redshift sample.
- Published
- 2012
37. Cryogenic Applications of Commercial Electronic Components
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Buchanan, Ernest D, Benford, Dominic J, Forgione, Joshua B, Moseley, S. Harvey, and Wollack, Edward J
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Electronics And Electrical Engineering - Abstract
We have developed a range of techniques useful for constructing analog and digital circuits for operation in a liquid Helium environment (4.2K), using commercially available low power components. The challenges encountered in designing cryogenic electronics include finding components that can function usefully in the cold and possess low enough power dissipation so as not to heat the systems they are designed to measure. From design, test, and integration perspectives it is useful for components to operate similarly at room and cryogenic temperatures; however this is not a necessity. Some of the circuits presented here have been used successfully in the MUSTANG and in the GISMO camera to build a complete digital to analog multiplexer (which will be referred to as the Cryogenic Address Driver board). Many of the circuit elements described are of a more general nature rather than specific to the Cryogenic Address Driver board, and were studied as a part of a more comprehensive approach to addressing a larger set of cryogenic electronic needs.
- Published
- 2012
38. Precision Attitude Control for the BETTII Balloon-Borne Interferometer
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Benford, Dominic J, Fixsen, Dale J, and Rinehart. Stephen
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Instrumentation And Photography - Abstract
The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter baseline far-infrared interferometer to fly on a high altitude balloon. Operating at wavelengths of 30-90 microns, BETTII will obtain spatial and spectral information on science targets at angular resolutions down to less than half an arcsecond, a capability unmatched by other far-infrared facilities. This requires attitude control at a level ofless than a tenth of an arcsecond, a great challenge for a lightweight balloon-borne system. We have designed a precision attitude determination system to provide gondola attitude knowledge at a level of 2 milliarcseconds at rates up to 100Hz, with accurate absolute attitude determination at the half arcsecond level at rates of up to 10Hz. A mUlti-stage control system involving rigid body motion and tip-tilt-piston correction provides precision pointing stability to the level required for the far-infrared instrument to perform its spatial/spectral interferometry in an open-loop control. We present key aspects of the design of the attitude determination and control and its development status.
- Published
- 2012
39. Enabling Large Focal Plane Arrays through Mosaic Hybridization
- Author
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Miller, Timothy M, Jhabvala, Christine A, Costen, Nick, and Benford, Dominic J
- Subjects
Electronics And Electrical Engineering - Abstract
We have demonstrated the hybridization of large mosaics of far-infrared detectors, joining separately fabricated sub-units into a single unit on a single, large substrate. We produced a single detector mockup on a 100mm diameter wafer and four mockup readout quadrant chips from a separate 100mm wafer. The individually fabricated parts were hybridized using a Suss FC150 flip chip bonder to assemble the detector-readout stack. Once all of the hybridized readouts were in place, a single, large and thick silicon substrate was placed on the stack and attached with permanent epoxy to provide strength and a Coefficient of Thermal Expansion (CTE) match to the silicon components underneath. Wirebond pads on the readout chips connect circuits to warm readout electronics; and were used to validate the successful superconducting electrical interconnection of the mockup mosaic-hybridized detector. This demonstration is directly scalable to 150 mm diameter wafers, enabling pixel areas over ten times the area currently demonstrated.
- Published
- 2012
40. First Detections of the [N II] 122 micron Line at High Redshift: Demonstrating the Utility of the Line for Studying Galaxies in the Early Universe
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Ferkinhoff, Carl, Brisbin, Drew, Nikola, Thomas, Parshley, Stephen C, Stacey, Gordon J, Phillips, Thomas G, Falgarone, Edith, Benford, Dominic J, Staguhn, Johannes G, and Tucker, Carol E
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Astrophysics - Abstract
We report the first detections of the [N II] 122 micron 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 (zeta) and Early Universe Spectrometer on the Caltech Submillimeter Observatory. The lines from both sources are quite bright with line to far-infrared (FIR) continuum luminosity ratios that are approx.7.0 x 10(exp -4) (Cloverleaf) and 2.1 x 10(exo -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, approx.8%-17% of the molecUlar gas mass. The [O III]/[N II] 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 active galactic nucleus (AGN). Using Our previous detection of the [O III] 88 micron line, the [O III]/[N II]line ratio for SMMJ02399-0136 indicates that the dominant source of the line emission is either stellar H II 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%-50% of the FIR lines arise in the NLR also matches the data. The Cloverleaf is best modeled by a superposition of approx.200 M82-like starbursts accounting for all of the FIR emission and 43% of the [N II]line. The remainder may come from the NLR. This war!< demonstrates the utility of the [N II] and [O III] lines in constraining properties of the ionized medium.
- Published
- 2011
- Full Text
- View/download PDF
41. Program Office Technology Management Process
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Benford, Dominic J
- Subjects
Administration And Management - Published
- 2011
42. First Detections of the [NII] 122 Micrometer Line at High Redshift: Demonstrating the Utility of the Line for Studying Galaxies in the Early Universe
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Ferkinhoff, Carl, Brisbin, Drew, Nikola, Thomas, Parshley, Stephen C, Stacey, Gordon J, Phillips, Thomas G, Falgarone, Edith, Benford, Dominic J, Staguhn, Johannes G, and Tucker, Carol E
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Astrophysics - Abstract
We report the first detections of the [NIl] 122 {\mu} m line from a high redshift galaxy. The line was strongly (> 6{\sigma}) detected from SMMJ02399-0136, and HI413+ 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 approx.7.0x10(exp -4) (Cloverleaf) and 2.1x10(exp -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, approx.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 [01II] 88 {\mu}m line, the [OIII]/ [NIl] line ratio for SMMJ02399-0136 indicates the dominant source of the line emission is either stellar HII regions ionized by 09.5 stars, or the NLR of the AGN with ionization parameter 10g(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 approx.200 M82like starbursts accounting for all of the FIR emission and 43% of the [NIl] line. The remainder may come from the NLR. This work demonstrates the utility of the [NIl] and [OIII] lines in constraining properties of the ionized medium.
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- 2011
43. Ultrasensitive Superconducting Transition Edge Sensors Based On Electron-Phonon Decoupling
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Jethava, Nikhil, Chervenak, James, Brown, Ari-David, Benford, Dominic, Kletetschka, Gunther, Mikula, Vilem, and U-yen, Kongpop
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Electronics And Electrical Engineering - Abstract
We have successfully fabricated the superconducting transition edge sensor (TES), bolometer technology that centers on the use of electron-phonon decoupling (EPD) to thermally isolate the bolometer. Along with material characterization for large format antenna coupled bolometer arrays, we present the initial test results of bolometer based on EPD designed for THz detection. We have selected a design approach that separates the two functions of photon absorption and temperature measurement, allowing separate optimization of the performance of each element. We have integrated Molybdenum/Gold (Mo/Au) bilayer TES and ion assisted thermally evaporated (IAE) Bismuth (Bi) films as radiation absorber coupled to a low-loss microstripline from Niobium (Nb) ground plane to a twin-slot antenna structure. The thermal conductance and the time constant of these devices have been measured, and are consistent with our calculations. The device exhibits a single time constant at 0.1 K of approx.160 IlS, which is compatible with readout by a high-bandwidth single SQUID or a time domain SQUID multiplexer. The effects of thermal conductance and electrothermal feedback are major determinants of the time constant, but the electronic heat capacity also plays a major role. The NEP achieved in the device described above is 2.5x10(exp -17)W(gamma)Hz. Our plan is to demonstrate a reduction of the volume in the superconducting element to 5 microns x 5 microns in films of half the thickness at Tc = 60mK. By calculation, this new geometry corresponds to an NEP reduction of two orders of magnitude to 2.5x10(exp -19)W/(gamma)Hz, with a time constant of ~130/ls.
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- 2011
44. How WISE Points to Future Far-Infrared Missions
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Benford, Dominic J, Leisawitz, D. T, and Wright, E. L
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Astronomy - Abstract
Based on the tantalizing science that is emerging from the first WISE discoveries, we consider the impact that the future will bring to far-infrared mission concepts. What we've learned from WISE gives us new investigations for missions like SPICA and SPIRIT. We highlight the new results from WISE and incorporate that into the context of the Far-Infrared Community Plan and the recent New Worlds, New Horizons documents. Plain-Language Abstract: Based on tantalizing science emerging from the first WISE discoveries, what we've learned gives us new investigations for missions like SPICA and SPIRIT. We highlight the new results from WISE and incorporate that into the context of the Far-Infrared Community Plan and the recent New Worlds, New Horizons documents.
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- 2011
45. Exploring the Universe with WISE and Cloud Computing
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Benford, Dominic J
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Astronomy - Abstract
WISE is a recently-completed astronomical survey mission that has imaged the entire sky in four infrared wavelength bands. The large quantity of science images returned consists of 2,776,922 individual snapshots in various locations in each band which, along with ancillary data, totals around 110TB of raw, uncompressed data. Making the most use of this data requires advanced computing resources. I will discuss some initial attempts in the use of cloud computing to make this large problem tractable.
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- 2011
46. WISE Deep and Wide Survey at 12 Microns
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Benford, Dominic J, Masci, Frank, Jarrett, Tom, Cutri, Roc, Eisenhardt, Peter, and Wright, Ned
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Astronomy - Abstract
We present the first results of a study of faint 12 micron sources detected with the WISE survey mission. A deep field around the north Ecliptic pole provides 5sigma sensitivity of around 100microJy, while a side field at high Galactic latitude provides an area of around 10 square degrees. Number counts for these sources are compared to smaller area and higher flux surveys carried out by ISO and IRAS. The WISE survey data show a continued increase in sources out to fainter limits.
- Published
- 2011
47. The First Hundred Brown Dwarfs Discovered by the Wide-Field Infrared Survey Explorer (WISE)
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Kirkpatrick, J. Davy, Cushing, Michael C, Gelino, Christopher R, Griffith, Roger L, Skrutskie, Michael F, Marsh, Kenneth A, Wright, Edward L, Mainzer, Amanda K, Eisenhardt, Peter R, McLean, Ian S, Bauer, James M, Benford, Dominic J, Lake, Sean E, Petty, Sara M, Tsai, Chao-Wei, Beichman, Charles, Stapelfeldt, Karl R, Stern, Daniel, and Vacca, William D
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Astronomy - Abstract
We present ground-based spectroscopic verification of six Y dwarfs also Cushing et al.), eighty-nine T dwarfs, eight L dwarfs, and one M dwarf identified by the Wide-field Infrared Survey Explorer (WISE). Eighty of these are cold brown dwarfs with spectral types > or =T6, six of which have been announced earlier in Mainzer et al. and I3urgasser et al. We present color-color and colortype diagrams showing the locus of M, L, T, and Y dwarfs in WISE color space. "
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- 2011
48. The Wide-Field Infrared Survey Explorer (WISE): Mission Description and Initial On-Orbit Performance
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Wright, Edward L, Eisenhardt, Peter R. M, Mainzer, Amy, Ressler, Michael E, Cutri, Roc M, Jarrett, Thomas, Kirkpatrick, J. Davy, Padgett, Deborah, McMillan, Robert S, Skrutskie,Michael, Stanford, S. A, Cohen, Martin, Walker, Russell G, Mather, John C, Leisawitz, David, Gautier, Thomas N., III, McLean, Ian, Benford, Dominic, Lonsdale,Carol J, Blain, Andrew, Mendez,Bryan, Irace, William R, Duval, Valerie, Liu, Fengchuan, and Royer, Don
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Astronomy - Abstract
The all sky surveys done by the Palomar Observatory Schmidt, the European Southern Observatory Schmidt, and the United Kingdom Schmidt, the InfraRed Astronomical Satellite and the 2 Micron All Sky Survey have proven to be extremely useful tools for astronomy with value that lasts for decades. The Wide-field Infrared Survey Explorer is mapping the whole sky following its launch on 14 December 2009. WISE began surveying the sky on 14 Jan 2010 and completed its first full coverage of the sky on July 17. The survey will continue to cover the sky a second time until the cryogen is exhausted (anticipated in November 2010). WISE is achieving 5 sigma point source sensitivities better than 0.08, 0.11, 1 and 6 mJy in unconfused regions on the ecliptic in bands centered at wavelengths of 3.4, 4.6, 12 and 22 micrometers. Sensitivity improves toward the ecliptic poles due to denser coverage and lower zodiacal background. The angular resolution is 6.1", 6.4", 6.5" and 12.0" at 3.4, 4.6, 12 and 22 micrometers, and the astrometric precision for high SNR sources is better than 0.15".
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- 2010
49. The Primordial Inflation Polarization Explorer (PIPER)
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Chuss, David T, Ade, Peter A. R, Benford, Dominic J, Bennett, Charles L, Dotson, Jessie L, Eimer, Joseph R, Fixsen, Dale J, Halpern, Mark, Hilton, Gene, Hinderks, James, Hinshaw, Gary, Irwin, Kent, Jackson, Michael L, Jah, Muzariatu A, Jethava, Nikhil, Jhabvala, Christine, Kogut, Alan J, Lowe, Luke, McCullagh, Nuala, Miller, Timothy, Mirel, Paul, Moseley, S. Harvey, Rodriguez, Samelys, Rostem, Karwan, and Sharp, Elmer
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Astronomy - Abstract
The Primordial Inflation Polarization Explorer (PIPER) is it balloon-borne instrument designed to search for the faint signature of inflation in the polarized component of the cosmic microwave background (C-N-113). Each flight will be configured for a single frequency, but in order to aid in the removal of the polarized foreground signal due to Galactic dust, the filters will be changed between flights. In this way, the CMB polarization at a total of four different frequencies (200, 270, 350, and 600 GHz) will be, measured on large angular scales. PIPER consists of a pair of cryogenic telescopes, one for measuring each of Stokes Q and U in the instrument frame. Each telescope receives both linear orthogonal polarizations in two 32 x 40 element planar arrays that utilize Transition-Edge Sensors (TES). The first element in each telescope is a variable-delay polarization modulator (VPM) that fully modulates the linear Stokes parameter to which the telescope is sensitive. There are several advantages to this architecture. First, by modulating at the front of the optics, instrumental polarization is unmodulated and is therefore cleanly separated from source polarization. Second, by implementing this system with the appropriate symmetry, systematic effects can be further mitigated. In the PIPER design, many of the. systematics are manifest in the unmeasured linear Stokes parameter for each telescope and this can be separated from the desired signal. Finally, the modulation cycle never mixes the Q and U linear Stokes parameters, and thus residuals in the modulation do not twist the observed polarization vector. This is advantageous because measuring the angle of linear polarization is critical for separating the inflationary signal from other polarized components.
- Published
- 2010
- Full Text
- View/download PDF
50. 5,120 Superconducting Bolometers for the PIPER Balloon-Borne CMB Polarization Experiment
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Benford, Dominic J, Chuss, David T, Hilton, Gene C, Irwin, Kent D, Jethava, Nikhil S, Jhabvala, Christine A, Kogut, Alan J, Miller, Timothy M, Mirel, Paul, Moseley, S. Harvey, Rostem, Karwan, Sharp, Elmer H, Staguhn, Johannes G, Stiehl, gregory M, Voellmer, George M, and Wollack, Edward J
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Astrophysics - Abstract
We are constructing the Primordial Inflation Polarization Explorer (PIPER) to measure the polarization o[ the cosmic microwave background (CMB) and search for the imprint of gravity waves produced during an inflationary epoch in the early universe. The signal is faint and lies behind confusing foregrounds, both astrophysical and cosmological, and so many detectors are required to complete the measurement in a limited time. We will use four of our matured 1,280 pixel, high-filling-factor backshort-under-grid bolometer arrays for efficient operation at the PIPER CMB wavelengths. All four arrays observe at a common wavelength set by passband filters in the optical path. PIPER will fly four times to observe at wavelengths of 1500, 1100, 850, and 500 microns in order to separate CMB from foreground emission. The arrays employ leg-isolated superconducting transition edge sensor bolometers operated at 128mK; tuned resonant backshorts for efficient optical coupling; and a second-generation superconducting quantum interference device (SQUID) multiplexer readout. We describe the design, development, and performance of PIPER bo|ometer array technology to achieve background-limited sensitivity for a cryogenic balloon-borne telescope.
- Published
- 2010
- Full Text
- View/download PDF
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