ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Counting and confusion: Bayesian rate estimation with multiple populations (2015)
    American Physical Society (APS)
    Details
    Publication Date: 2015-01-23
    Description: Author(s): Will M. Farr, Jonathan R. Gair, Ilya Mandel, and Curt Cutler We show how to obtain a Bayesian estimate of the rates or numbers of signal and background events from a set of events when the shapes of the signal and background distributions are known, can be estimated, or approximated; our method works well even if the foreground and background event distributi... [Phys. Rev. D 91, 023005] Published Thu Jan 22, 2015
    Keywords: Astrophysics
    Print ISSN: 0556-2821
    Electronic ISSN: 1089-4918
    Topics: Physics
    Published by American Physical Society (APS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    Parameter Estimation for Compact Binary Coalescence Signals with the First Generation Gravitational-Wave Detector Network (2013)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: Compact binary systems with neutron stars or black holes are one of the most promising sources for ground-based gravitational-wave detectors. Gravitational radiation encodes rich information about source physics; thus parameter estimation and model selection are crucial analysis steps for any detection candidate events. Detailed models of the anticipated waveforms enable inference on several parameters, such as component masses, spins, sky location and distance, that are essential for new astrophysical studies of these sources. However, accurate measurements of these parameters and discrimination of models describing the underlying physics are complicated by artifacts in the data, uncertainties in the waveform models and in the calibration of the detectors. Here we report such measurements on a selection of simulated signals added either in hardware or software to the data collected by the two LIGO instruments and the Virgo detector during their most recent joint science run, including a blind injection where the signal was not initially revealed to the collaboration. We exemplify the ability to extract information about the source physics on signals that cover the neutron-star and black-hole binary parameter space over the component mass range 1M25M and the full range of spin parameters. The cases reported in this study provide a snapshot of the status of parameter estimation in preparation for the operation of advanced detectors.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN12729 , Physical Review D (ISSN 2470-0010) (e-ISSN 2470-0029); 88; 062001
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Reconstructing the Sky Location of Gravitational-Wave Detected Compact Binary Systems: Methodology for Testing and Comparison (2014)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: The problem of reconstructing the sky position of compact binary coalescences detected via gravitational waves is a central one for future observations with the ground-based network of gravitational-wave laser interferometers, such as Advanced LIGO and Advanced Virgo. Different techniques for sky localization have been independently developed. They can be divided in two broad categories: fully coherent Bayesian techniques, which are high latency and aimed at in-depth studies of all the parameters of a source, including sky position, and "triangulation-based" techniques, which exploit the data products from the search stage of the analysis to provide an almost real-time approximation of the posterior probability density function of the sky location of a detection candidate. These techniques have previously been applied to data collected during the last science runs of gravitational-wave detectors operating in the so-called initial configuration. Here, we develop and analyze methods for assessing the self consistency of parameter estimation methods and carrying out fair comparisons between different algorithms, addressing issues of efficiency and optimality. These methods are general, and can be applied to parameter estimation problems other than sky localization. We apply these methods to two existing sky localization techniques representing the two above-mentioned categories, using a set of simulated inspiralonly signals from compact binary systems with a total mass of equal to or less than 20M solar mass and nonspinning components. We compare the relative advantages and costs of the two techniques and show that sky location uncertainties are on average a factor approx. equals 20 smaller for fully coherent techniques than for the specific variant of the triangulation-based technique used during the last science runs, at the expense of a factor approx. equals 1000 longer processing time.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN15448 , Physical Review D; 89; 8; 084060
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Going the Distance: Mapping Host Galaxies of LIGO and VIRGO Sources in Three Dimensions using Local Cosmography and Targeted Follow-Up (2016)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: The Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) discovered gravitational waves (GWs) from a binary black hole merger in 2015 September and may soon observe signals from neutron star mergers. There is considerable interest in searching for their faint and rapidly fading electromagnetic (EM) counterparts, though GW position uncertainties are as coarse as hundreds of square degrees. Because LIGO's sensitivity to binary neutron stars is limited to the local universe, the area on the sky that must be searched could be reduced by weighting positions by mass, luminosity, or star formation in nearby galaxies. Since GW observations provide information about luminosity distance, combining the reconstructed volume with positions and redshifts of galaxies could reduce the area even more dramatically. A key missing ingredient has been a rapid GW parameter estimation algorithm that reconstructs the full distribution of sky location and distance. We demonstrate the first such algorithm, which takes under a minute, fast enough to enable immediate EM follow-up. By combining the three-dimensional posterior with a galaxy catalog, we can reduce the number of galaxies that could conceivably host the event by a factor of 1.4, the total exposure time for the Swift X-ray Telescope by a factor of 2, the total exposure time for a synoptic optical survey by a factor of 2, and the total exposure time for a narrow-field optical telescope by a factor of 3. This encourages us to suggest a new role for small field of view optical instruments in performing targeted searches of the most massive galaxies within the reconstructed volumes.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN44008 , The American Astronomical Society (ISSN 0004-637X) (e-ISSN 1538-4357); 829; 1; L15
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    The LOFT Mission Concept - A Status Update (2016)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: The Large Observatory For x-ray Timing (LOFT) is a mission concept which was proposed to ESA as M3 and M4 candidate in the framework of the Cosmic Vision 2015-2025 program. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument and the uniquely large field of view of its wide field monitor, LOFT will be able to study the behaviour of matter in extreme conditions such as the strong gravitational field in the innermost regions close to black holes and neutron stars and the supra-nuclear densities in the interiors of neutron stars. The science payload is based on a Large Area Detector (LAD, is greater than 8m2 effective area, 2-30 keV, 240 eV spectral resolution, 1 degree collimated field of view) and a Wide Field Monitor (WFM, 2-50 keV, 4 steradian field of view, 1 arcmin source location accuracy, 300 eV spectral resolution). The WFM is equipped with an on-board system for bright events (e.g., GRB) localization. The trigger time and position of these events are broadcast to the ground within 30 s from discovery. In this paper we present the current technical and programmatic status of the mission.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN44111 , SPIE Astronomical Telescopes + Instrumentation; Jun 26, 2016 - Jul 01, 2016; Edinburgh, Scotland; United Kingdom|Space Telescopes and Instrumentation 2016: Ultraviolet to Gamma Ray; 9905; 99051R
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    Electronic Resource
    Electronic Resource
    The physical chemistry of polyelectrolyte solutionsPaper presented at the meeting of the GDCh-Fachgruppe “Makromolekulare Chemie” on “Polymers and Water” in Bad Nauheim (W-Germany) on April 2/3 1984. (1984)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 123 (1984), S. 63-83 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Some physical properties of aqueous solutions containing linear, flexible, polyelectrolytes are reviewed in order to emphasize the role of charge interactions in these systems which strongly depend on the charge of the macromolecular chain and the concentration of low molar mass electrolyte in solution. Particular emphasis is put on polyelectrolyte solutions containing an excess of added salt, which from a theoretical point of view are easier to understand. Both the dilute and the semi-dilute case will be discussed. In the former the problem of the electrostatic potential around the macromolecular chain is briefly reviewed as well as the use of a wormlike chain model to derive average dimensions of polyelectrolytes in solutions. In the latter the scaling approach to concentration effects in polyelectrolyte solutions is briefly discussed. The pecularities of the semi-dilute regime in polyelectrolyte solutions is illustrated with the help of results obtained with dynamic light scattering and the time dependent decay of electric birefringence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1984.051230103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Das Mischzeitverhalten bei sehr geringen Konzentrationen (1993)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 65 (1993), S. 68-70 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330650111
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Dielectric properties of maleic acid-ethylene copolymer in salt-free aqueous solutions (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 16 (1978), S. 641-651 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The dielectric behavior of maleic acid-ethylene copolymer solutions has been investigated at different polymer concentrations and two degrees of neutralization α′. It is shown that this behavior is analogous to that of ordinary polyacids. Also the experimental data can be explained in terms of the van der Touw-Mandel theory, but at low α′ a possible contribution from motion of negative charges (in turn related to bound proton fluctuations) has to be taken into account. The dielectric results suggest that the formation of intramolecular hydrogen bonds has an influence on the change of the average dimensions of the chain with increasing α′. This seems to be confirmed by viscosity data.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.180160406
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The conformational transition in partially esterified poly-(methacrylic acid) (1964)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 80 (1964), S. 141-148 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Konformationsumwandlung von teilweise veresterter Polymethacrylsüre wurde mit Hilfe der potentiometrischen Titration untersucht.Es wurde gefunden, daß die Stabilität der bei kleinem Dissoziationsgrad (α) vorliegenden Form nicht vermindert wird, wenn die Zahl jener Kettenglieder, die intramolekulare Wasserstoffbrücken ausbilden können, abnimmt. Es zeigt sich vielmehr, daß die Umwandlung mit der mittleren Ladung pro Struktureinheit zusammenhängt. Dies stützt die Hypothese, wonach die bei kleinen α-Werten stabile Form eine kompaktere Struktur besitzt, die möglicherweise durch VAN DER WAALsche Wechselwirkungen zwischen den  - CH3-Gruppen stabilisiert ist.
    Notes: The conformational transition of poly-(methacrylic acid), partially esterified with dimethyl sulfate, has been studied using potentiometric titration at constant temperature.It is found that the stability of the form existing at low values of dissociation (α) is not decreased by reducing the number of groups on the chain capable of establishing intramolecular hydrogen bonds. The transition is also shown to depend on the average charge per monomeric unit. This confirms the hypothesis that the stable form at low α-values is a compact structure stabilized probably by VAN DER WAALS attractions between  - CH3 groups.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1964.020800112
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Empirical approach to the potentiometric titration curve of weak polyacids (1970)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 8 (1970), S. 1841-1844 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1970.160081019
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...