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  • Astrophysics  (4)
  • Engineering (General)  (3)
  • GEOPHYSICS
  • 2015-2019  (7)
  • 1975-1979
  • 1965-1969
  • 2017  (7)
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  • 2015-2019  (7)
  • 1975-1979
  • 1965-1969
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  • 1
    Publication Date: 2019-07-13
    Description: We present C I(21) and multi-transition C-12 O observations of a dusty star-forming galaxy, ACT J2029+0120,which we spectroscopically confirm to lie at zeta = 2.64. We detect CO(3-2), CO(5-4), CO(7-6), CO(8-7), and C I(2-1) at high significance, tentatively detect HCO+(4-3), and place strong upper limits on the integrated strength of dense gas tracers (HCN(4-3) and CS(7-6)). Multi-transition CO observations and dense gas tracers can provide valuable constraints on the molecular gas content and excitation conditions in high-redshift galaxies. We therefore use this unique data set to construct a CO spectral line energy distribution (SLED) of the source, which is most consistent with that of a ULIRG Seyfert or QSO host object in the taxonomy of the Herschel Comprehensive ULIRG Emission Survey. We employ RADEX models to fit the peak of the CO SLED, inferring a temperature of T approximately 117 K and n(sub H2) approximately 10(exp5) cm(exp -3), most consistent with a ULIRGQSO object and the presence of high-density tracers. We also find that the velocity width of the C I line is potentially larger than seen in all CO transitions forth is object, and that the L'(sub Ci(2-1))/L'(sub CO(3-2))ratio is also larger than seen in other lensed and unlensed submillimeter galaxies and QSO hosts; if confirmed, this anomaly could be an effect of differential lensing of a shocked molecular outflow.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN46867 , The Astrophysical Journal (ISSN 0004-637X) (e-ISSN 1538-4357); 844; 2; 110
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  • 2
    Publication Date: 2019-07-27
    Description: A full understanding of LISA (Laser Interferometer Space Antenna)'s science capability will require accurate models of incident waveform signals and the instrumental response. While Fisher matrix analysis is useful for some estimates, a full Bayesian treatment is needed for important cases at the limit of LISA's capability. We will apply fast analysis algorithms enabling accurate treatment with EOB (effective-one-body) waveforms and the full-featured LISA response to study the significance of higher spherical harmonics and mergers in LISA analysis.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN56728 , International LISA (Laser Interferometer Space Antenna) Symposium; 5ý9 Sep. 2016; Zurich; Switzerland|Journal of Physics: Conference Series; 840; 1; 012051
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  • 3
    Publication Date: 2019-08-14
    Description: We are developing miniaturized, highly integrated Schottky receiver systems suitable for use in CubeSats or other small spacecraft platforms, where state-of-the-art performance and ultra-low mass, power, and volume are required. Current traditional Schottky receivers are too large to employ on a CubeSat. We will develop highly integrated receivers operating from 520-600 GHz and 1040-1200 GHz that are based on state-of-the-art receivers already developed at Jet Propulsion Laboratory (JPL) by using novel 3D multi layer packaging. This process will reduce both mass and volume by more than an order of magnitude, while preserving state-of-the-art noise performance. The resulting receiver systems will have a volume of approximately 25 x 25 x 40 millimeters (mm), a mass of 250 grams (g), and power consumption on the order of of 7 watts (W). Using these techniques, we will also integrate both receivers into a single frame, further reducing mass and volume for applications where dual band operation is advantageous. Additionally, as Schottky receivers offer significant gains in noise performance when cooled to 100 K, we will investigate the improvement gained by passively cooling these receivers. Work by Sierra Lobo Inc., with their Cryo Cube technology development program, offers the possibility of passive cooling to 100 K on CubeSat platforms for 1-unit (1U) sized instruments.
    Keywords: Engineering (General)
    Type: NASA FS-2017-03-03-ARC , ARC-E-DAA-TN45665
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  • 4
    Publication Date: 2019-08-14
    Description: This project will develop an efficient smoothing software for incremental estimation of the relative poses and velocities between multiple, small spacecraft in a formation, and a small, long range depth sensor based on coded aperture imaging that is capable of identifying other spacecraft in the formation. The smoothing algorithm will obtain the maximum a posteriori estimate of the relative poses between the spacecraft by using all available sensor information in the spacecraft formation.This algorithm will be portable between different satellite platforms that possess different sensor suites and computational capabilities, and will be adaptable in the case that one or more satellites in the formation become inoperable. It will obtain a solution that will approach an exact solution, as opposed to one with linearization approximation that is typical of filtering algorithms. Thus, the algorithms developed and demonstrated as part of this program will enhance the applicability of small spacecraft to multi-platform operations, such as precisely aligned constellations and fractionated satellite systems.
    Keywords: Engineering (General)
    Type: NASA FS-2017-03-03-ARC , ARC-E-DAA-TN45663
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  • 5
    Publication Date: 2019-08-14
    Description: This collaborative multi-disciplinary effort aims to develop a lightweight, 1-unit (1U) CubeSat (10x10x10 cm) which utilizes improved and fully integrated structural battery materials for mission life extension, larger payload capability, and significantly reduced mass.The electrolytic carbon fiber material serves the multifunctional capacitive energy system as both a lightweight, load bearing structure and an electrochemical battery system. This implementation will improve traditional multifunctional energy storage concepts with a highly effective energy storage capability.
    Keywords: Engineering (General)
    Type: NASA FS-2017-03-03-ARC , ARC-E-DAA-TN45660
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  • 6
    Publication Date: 2019-07-13
    Description: Binary black hole (BBH) mergers provide a prime source for current and future interferometric gravitational wave observatories. Massive BBH mergers may often take place in plasma-rich environments, leading to the exciting possibility of a concurrent electromagnetic (EM) signal observable by traditional astronomical facilities. However, many critical questions about the generation of such counterparts remain unanswered. We explore mechanisms that may drive EM counterparts with magnetohydrodynamic simulations treating a range of scenarios involving equal-mass black-hole binaries immersed in an initially homogeneous fluid with uniform, orbitally aligned magnetic fields. We find that the time development of Poynting luminosity, which may drive jetlike emissions, is relatively insensitive to aspects of the initial configuration. In particular, over a significant range of initial values, the central magnetic field strength is effectively regulated by the gas flow to yield a Poynting luminosity of 1 0 Exp 45) 10(exp 46) (sub 13) M(sub 8)(exp 2) erg s(exp 1), with BBH mass scaled to M(sub 8) M / ( 10 8 M ) and ambient density 13 / ( 10(exp 13) g cm(sub 3)). We also calculate the direct plasma synchrotron emissions processed through geodesic ray-tracing. Despite lensing effects and dynamics, we find the observed synchrotron flux varies little leading up to merger.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN54261 , Physical Review D - Particles, Fields, Gravitation and Cosmology (ISSN 1550-7998) (e-ISSN 1550-2368); 96; 12; 123003
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  • 7
    Publication Date: 2019-07-13
    Description: Binary black hole (BBH) mergers provide a prime source for current and future interferometric GW observatories. Massive BBH mergers may often take place in plasma-rich environments, leading to the exciting possibility of a concurrent electromagnetic (EM) signal observable by traditional astronomical facilities. However, many critical questions about the generation of such counterparts remain unanswered. We explore mechanisms that may drive EM counterparts with magnetohydrodynamic simulations treating a range of scenarios involving equal-mass black-hole binaries immersed in an initially homogeneous fluid with uniform, orbitally aligned magnetic fields. We find that the time development of Poynting luminosity, which may drive jet-like emissions, is relatively insensitive to aspects of the initial configuration. In particular, over a significant range of initial values, the central magnetic field strength is effectively regulated by the gas flow to yield a Poynting luminosity of 10(exp 45) - 10(exp 46) (p-13) M(sub 8)(exp 2) erg/s, with BBH mass scaled to M(sub 8) defined to be equal to M=(10(exp 8) solar mass) and ambient density p -13 defined to be equal to p/(10(exp -13) g/cu.cm). We also calculate the direct plasma synchrotron emissions processed through geodesic ray-tracing. Despite lensing effects and dynamics, we find the observed synchrotron flux varies little leading up to merger.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN51364 , Physical Review D - Particles, Fields, Gravitation and Cosmology (ISSN 1550-7998) (e-ISSN 1550-2368); 96; 12; 123003
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