Destiny: A Candidate Architecture for the Joint Dark Energy Mission

Destiny is a simple, direct, low cost mission to determine the properties of dark energy by obtaining a cosmologically deep supernova (SN) type Ia Hubble diagram. Operated at L2, its science instrument is a 1.65m space telescope, featuring a grism-fed near-infrared (NIR) (0.85-1.7micron) survey camera/spectrometer with a 0.12 square degree field of view. During its two-year primary mission, Destiny will detect, observe, and characterize ~3000 SN Ia events over the redshift interval 0.4<z<1.7 within a 3 square degree survey area. In conjunction with ongoing ground-based SN Ia surveys for z<0.8, Destiny mission data will be used to construct a high-precision Hubble diagram and thereby constrain the dark energy equation of state from a time when it was strongly matter-dominated to the present when dark energy dominates. The grism-images simultaneously provide broad-band photometry, redshifts, and SN classification, as well as time-resolved diagnostic data for investigating additional SN luminosity diagnostics. Destiny will be used in its third year as a high resolution, wide-field imager to conduct a multicolor NIR weak lensing (WL) survey covering 1000 square degrees. The large-scale mass power spectrum derived from weak lensing distortions of field galaxies as a function of redshift will provide independent and complementary constraints on the dark energy equation of state. The combination of SN and WL is much more powerful than either technique on its own. Used together, these surveys will have more than an order of magnitude greater sensitivity than will be provided by ongoing ground-based projects. The dark energy parameters, w_0 and w_a, will be measured to a precision of 0.05 and 0.2 respectively.Comment: Contains full color figure

Dual Fabry-Perot filter for measurement of CO rotational spectra: design and application to the CO spectrum of Venus

We present the design of a harmonic resonant filter that can be used with a Fourier transform spectrometer (FTS) for simultaneous measurement of a series of lines in the CO rotational ladder. To enable studies of both broad CO absorptions in Venus and modestly red-shifted CO emission from external galaxies, relatively broad (approximately 10-30-GHz FWHM) transmission passbands are desirable. Because a single low-finesse Fabry Perot (FP) etalon has insufficient interline rejection, a dual-FP etalon was considered. Such a design provides significantly better interband rejection and somewhat more flattopped transmission spikes. A prototype filter of this type, made of two thin silicon disks spaced by an air gap, has been constructed and used with our FTS at the Caltech Submillimeter Observatory for simultaneous measurement of the four submillimeter CO transitions in the atmosphere of Venus that are accessible from the ground

Scientific Objectives for UV/Visible Astrophysics Investigations: A Summary of Responses by the Community (2012)

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.Comment: 22 pages, 1 figure, 3 table

Wide-field Infrared Survey Explorer Observations of the Evolution of Massive Star-forming Regions

We present the results of a mid-infrared survey of 11 outer Galaxy massive star-forming regions and 3 open clusters with data from the Wide-field Infrared Survey Explorer (WISE). Using a newly developed photometric scheme to identify young stellar objects and exclude extragalactic contamination, we have studied the distribution of young stars within each region. These data tend to support the hypothesis that latter generations may be triggered by the interaction of winds and radiation from the first burst of massive star formation with the molecular cloud material leftover from that earlier generation of stars. We dub this process the "fireworks hypothesis" since star formation by this mechanism would proceed rapidly and resemble a burst of fireworks. We have also analyzed small cutout WISE images of the structures around the edges of these massive star-forming regions. We observe large (1-3 pc size) pillar and trunk-like structures of diffuse emission nebulosity tracing excited polycyclic aromatic hydrocarbon molecules and small dust grains at the perimeter of the massive star-forming regions. These structures contain small clusters of emerging Class I and Class II sources, but some are forming only a single to a few new stars

The Urban Political Ecology of Post-industrial Scottish Towns: Examining Greengairs and Ravenscraig

Urban ecological politics is shaped by both moments of concerted action and more silent perceptions and responses. Instead of only being evident in situations of organised protest, the politics of urban ecology is also manifested, in material and symbolic terms, in the daily life of the residents. The fragmentation of urban political ecology turns out to be an important element in the affirmation of post-political forms of urban governance. Those issues were the object of fieldwork research carried out in Greengairs and Ravenscraig, two towns in North Lanarkshire, near Glasgow, with the goal of unravelling the understanding and the coping mechanisms of environmentally deprived residents. The towns are permeated by a widespread, often dissimulated, political ecology that is nonetheless always present. Empirical results demonstrate that a more comprehensive handling of the political ecology of the urban is crucial in order to halt the sources of marginalisation and ecological degradation

Sensitive Radio Observations of High Redshift Dusty QSOs

We present sensitive radio continuum imaging at 1.4 GHz and 4.9 GHz of seven high redshift QSOs selected for having a 240 GHz continuum detection, which is thought to be thermal dust emission. We detect radio continuum emission from four of the sources: BRI 0952-0115, BR 1202-0725, LBQS 1230+1627B, and BRI 1335-0417. The radio source in BR 1202-0725 is resolved into two components, coincident with the double mm and CO sources. We compare the results at 1.4 GHz and 240 GHz to empirical and semi-analytic spectral models based on star forming galaxies at low redshift. The radio-to-submm spectral energy distribution for BR 1202-0725, LBQS 1230+1627B, and BRI 1335-0417 are consistent with that expected for a massive starburst galaxy, with implied massive star formation rates of order 1000 solar masses per year (without correcting for possible amplification by gravitational lensing). The radio-to-submm spectral energy distribution for BRI 0952-0115 suggests a low-luminosity radio jet source driven by the AGN.Comment: 12 pages, Latex emulateapj format, including 1 table and 3 figures. The Astrophysical Journal, to appear in the January 2000 issu

On DESTINY Science Instrument Electrical and Electronics Subsystem Framework

Future space missions are going to require large focal planes with many sensing arrays and hundreds of millions of pixels all read out at high data rates'' . This will place unique demands on the electrical and electronics (EE) subsystem design and it will be critically important to have high technology readiness level (TRL) EE concepts ready to support such missions. One such omission is the Joint Dark Energy Mission (JDEM) charged with making precise measurements of the expansion rate of the universe to reveal vital clues about the nature of dark energy - a hypothetical form of energy that permeates all of space and tends to increase the rate of the expansion. One of three JDEM concept studies - the Dark Energy Space Telescope (DESTINY) was conducted in 2008 at the NASA's Goddard Space Flight Center (GSFC) in Greenbelt, Maryland. This paper presents the EE subsystem framework, which evolved from the DESTINY science instrument study. It describes the main challenges and implementation concepts related to the design of an EE subsystem featuring multiple focal planes populated with dozens of large arrays and millions of pixels. The focal planes are passively cooled to cryogenic temperatures (below 140 K). The sensor mosaic is controlled by a large number of Readout Integrated Circuits and Application Specific Integrated Circuits - the ROICs/ASICs in near proximity to their sensor focal planes. The ASICs, in turn, are serviced by a set of "warm" EE subsystem boxes performing Field Programmable Gate Array (FPGA) based digital signal processing (DSP) computations of complex algorithms, such as sampling-up-the-ramp algorithm (SUTR), over large volumes of fast data streams. The SUTR boxes are supported by the Instrument Control/Command and Data Handling box (ICDH Primary and Backup boxes) for lossless data compression, command and low volume telemetry handling, power conversion and for communications with the spacecraft. The paper outlines how the JDEM DESTINY concept instrument EE subsystem can be built now, a design; which is generally U.S. Government work not protected by U.S. copyright IEEEAC paper # 1429. Version 4. Updated October 19, 2009 applicable to a wide variety of missions using large focal planes with lar ge mosaics of sensors

350 Micron Dust Emission from High Redshift Objects

We report observations of a sample of high redshift sources (1.8<z<4.7), mainly radio-quiet quasars, at 350 microns using the SHARC bolometer camera at the Caltech Submillimeter Observatory. Nine sources were detected (>4-sigma) and upper limits were obtained for 11 with 350 micron flux density limits (3-sigma) in the range 30-125mJy. Combining published results at other far-infrared and millimeter wavelengths with the present data, we are able to estimate the temperature of the dust, finding relatively low values, averaging 50K. From the spectral energy distribution, we derive dust masses of a few 10^8 M_sun and luminosities of 4-33x10^{12} L_sun (uncorrected for any magnification) implying substantial star formation activity. Thus both the temperature and dust masses are not very different from those of local ultraluminous infrared galaxies. For this redshift range, the 350 micron observations trace the 60-100 micron rest frame emission and are thus directly comparable with IRAS studies of low redshift galaxies.Comment: 5 pages, 2 PS figures. Accepted for publication in Astrophysical Journal Letter

Submillimeter Imaging of NGC 891 with SHARC

The advent of submillimeter wavelength array cameras operating on large ground-based telescopes is revolutionizing imaging at these wavelengths, enabling high-resolution submillimeter surveys of dust emission in star-forming regions and galaxies. Here we present a recent 350 micron image of the edge-on galaxy NGC 891, which was obtained with the Submillimeter High Angular Resolution Camera (SHARC) at the Caltech Submillimeter Observatory (CSO). We find that high resolution submillimeter data is a vital complement to shorter wavelength satellite data, which enables a reliable separation of the cold dust component seen at millimeter wavelengths from the warmer component which dominates the far-infrared (FIR) luminosity.Comment: 4 pages LaTeX, 2 EPS figures, with PASPconf.sty; to appear in "Astrophysics with Infrared Surveys: A Prelude to SIRTF