Institution
University of Maryland, Baltimore County
Education•Baltimore, Maryland, United States•
About: University of Maryland, Baltimore County is a education organization based out in Baltimore, Maryland, United States. It is known for research contribution in the topics: Population & Aerosol. The organization has 8749 authors who have published 20843 publications receiving 795706 citations. The organization is also known as: UMBC.
Papers published on a yearly basis
Papers
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TL;DR: The long-term multi-wavelength light curve of M 87, spanning from radio to VHE and including data from Hubble Space Telescope, Liverpool Telescope, Very Large Array, and European VLBI Network, is used to further investigate the origin of the VHE gamma-ray emission.
Abstract: The giant radio galaxy M 87 with its proximity (16 Mpc), famous jet, and very massive black hole ((3-6) x 10(9) M-circle dot) provides a unique opportunity to investigate the origin of very high energy (VHE; E > 100 GeV) gamma-ray emission generated in relativistic outflows and the surroundings of supermassive black holes. M 87 has been established as a VHE gamma-ray emitter since 2006. The VHE gamma-ray emission displays strong variability on timescales as short as a day. In this paper, results from a joint VHE monitoring campaign on M 87 by the MAGIC and VERITAS instruments in 2010 are reported. During the campaign, a flare at VHE was detected triggering further observations at VHE (H.E.S.S.), X-rays (Chandra), and radio (43 GHz Very Long Baseline Array, VLBA). The excellent sampling of the VHE gamma-ray light curve enables one to derive a precise temporal characterization of the flare: the single, isolated flare is well described by a two-sided exponential function with significantly different flux rise and decay times of tau(rise)(d) = (1.69 +/- 0.30) days and tau(decay)(d) = (0.611 +/- 0.080) days, respectively. While the overall variability pattern of the 2010 flare appears somewhat different from that of previous VHE flares in 2005 and 2008, they share very similar timescales (similar to day), peak fluxes (Phi(>0.35 TeV) similar or equal to (1-3) x 10(-11) photons cm(-2) s(-1)), and VHE spectra. VLBA radio observations of 43 GHz of the inner jet regions indicate no enhanced flux in 2010 in contrast to observations in 2008, where an increase of the radio flux of the innermost core regions coincided with a VHE flare. On the other hand, Chandra X-ray observations taken similar to 3 days after the peak of the VHE gamma-ray emission reveal an enhanced flux from the core (flux increased by factor similar to 2; variability timescale <2 days). The long-term (2001-2010) multi-wavelength (MWL) light curve of M 87, spanning from radio to VHE and including data from Hubble Space Telescope, Liverpool Telescope, Very Large Array, and European VLBI Network, is used to further investigate the origin of the VHE gamma-ray emission. No unique, common MWL signature of the three VHE flares has been identified. In the outer kiloparsec jet region, in particular in HST-1, no enhanced MWL activity was detected in 2008 and 2010, disfavoring it as the origin of the VHE flares during these years. Shortly after two of the three flares (2008 and 2010), the X-ray core was observed to be at a higher flux level than its characteristic range (determined from more than 60 monitoring observations: 2002-2009). In 2005, the strong flux dominance of HST-1 could have suppressed the detection of such a feature. Published models for VHE gamma-ray emission from M 87 are reviewed in the light of the new data.
185 citations
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Goddard Space Flight Center1, University of Maryland, Baltimore County2, Universities Space Research Association3, Emory University4, Argonne National Laboratory5, Langley Research Center6, Lamont–Doherty Earth Observatory7, Saint Louis University8, University of Colorado Boulder9, National Oceanic and Atmospheric Administration10, Geophysical Fluid Dynamics Laboratory11, National Center for Atmospheric Research12
TL;DR: The primary uses of satellite data for air quality applications are reviewed, some background information on satellite capabilities for measuring pollutants are provided, the many resources available to the end-user for accessing, processing, and visualizing the data are discussed, and answers to common questions in plain language are provided.
185 citations
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TL;DR: A novel nanofluidic biosensor using a controlled, reproducible surface enhanced Raman spectroscopy active site was developed to observe Abeta in different conformational states during the Abeta self-assembly process as well as to distinguish Abeta from confounder proteins commonly found in cerebral spinal fluid.
Abstract: Trace detection of the conformational transition of beta-amyloid peptide (Abeta) from a predominantly alpha-helical structure to beta-sheet could have a large impact in understanding and diagnosing Alzheimer's disease. We demonstrate how a novel nanofluidic biosensor using a controlled, reproducible surface enhanced Raman spectroscopy active site was developed to observe Abeta in different conformational states during the Abeta self-assembly process as well as to distinguish Abeta from confounder proteins commonly found in cerebral spinal fluid.
185 citations
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TL;DR: In this paper, the authors summarized recent improvements in the development of bulk scattering/absorption models at solar wavelengths and combined microphysical measurements from various field campaigns with single-scattering properties for nine habits including droxtals, plates, solid/hollow columns, solid-hollow bullet rosettes, and several types of aggregates.
Abstract: This study summarizes recent improvements in the development of bulk scattering/absorption models at solar wavelengths. The approach combines microphysical measurements from various field campaigns with single-scattering properties for nine habits including droxtals, plates, solid/hollow columns, solid/hollow bullet rosettes, and several types of aggregates. Microphysical measurements are incorporated from a number of recent field campaigns in both the Northern and Southern Hemisphere. A set of 12 815 particle size distributions is used for which Tcld ≤ −40°C. The ice water content in the microphysical data spans six orders of magnitude. For evaluation, a library of ice-particle single-scattering properties is employed for 101 wavelengths between 0.4 and 2.24 μm. The library includes the full phase matrix as well as properties for smooth, moderately roughened, and severely roughened particles. Habit mixtures are developed for generalized cirrus, midlatitude cirrus, and deep tropical convection. Th...
185 citations
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TL;DR: In this article, the authors integrated observations from space-borne sensors, namely MODIS and CALIPSO, together with ground sunphotometer measurements, to infer dust loading in the pre-monsoon aerosol build-up over source and sink regions in northern India.
Abstract: [1] Each year, prior to the onset of the Indian Summer Monsoon, the Gangetic Plains (GP), bounded by the high-altitude Himalayan mountains, are strongly influenced by the transport of dust outbreaks originating in the northwestern desert in India (known as the Thar Desert). Dust particles constitute the bulk of the regional aerosol loading which peaks annually during the pre-monsoon season. This paper integrates observations from space-borne sensors, namely MODIS and CALIPSO, together with ground sunphotometer measurements, to infer dust loading in the pre-monsoon aerosol build-up over source and sink regions in northern India. Detailed aerosol characterization from the synergetic observational assessment suggests that the two pre-monsoon seasons of 2007 and 2008 were strikingly contrasting in terms of the dust loading over both the Thar Desert and the GP. Further analysis of aerosol loading and optical properties, from the entire record of MODIS and sunphotometer observations, reveals that the 2007 pre-monsoon season was an unusually weak dust-laden period. Our findings suggest the plausible role of the immediately preceding excess winter monsoon rainfall in the suppressed dust activity during the 2007 pre-monsoon season.
185 citations
Authors
Showing all 8862 results
Name | H-index | Papers | Citations |
---|---|---|---|
Robert C. Gallo | 145 | 825 | 68212 |
Paul T. Costa | 133 | 406 | 88454 |
Igor V. Moskalenko | 132 | 542 | 58182 |
James Chiang | 129 | 308 | 60268 |
Alex K.-Y. Jen | 128 | 921 | 61811 |
Alan R. Shuldiner | 120 | 557 | 71737 |
Richard N. Zare | 120 | 1201 | 67880 |
Vince D. Calhoun | 117 | 1234 | 62205 |
Rita R. Colwell | 115 | 781 | 55229 |
Kendall N. Houk | 112 | 997 | 54877 |
Elliot K. Fishman | 112 | 1335 | 49298 |
Yoram J. Kaufman | 111 | 263 | 59238 |
Paulo Artaxo | 107 | 454 | 44346 |
Braxton D. Mitchell | 102 | 558 | 49599 |
Sushil Jajodia | 101 | 664 | 35556 |