Institution
Goddard Space Flight Center
Facility•Greenbelt, Maryland, United States•
About: Goddard Space Flight Center is a facility organization based out in Greenbelt, Maryland, United States. It is known for research contribution in the topics: Galaxy & Solar wind. The organization has 19058 authors who have published 63344 publications receiving 2786037 citations. The organization is also known as: GSFC & Space Flight Center.
Topics: Galaxy, Solar wind, Magnetosphere, Stars, Population
Papers published on a yearly basis
Papers
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TL;DR: The role of naturally varying vegetation in influencing the climate variability in the West African Sahel is explored in a coupled atmosphere-land-vegetation model and interactive vegetation enhances the interdecadal variation substantially but can reduce year-to-year variability.
Abstract: The role of naturally varying vegetation in influencing the climate variability in the West African Sahel is explored in a coupled atmosphere-land-vegetation model. The Sahel rainfall variability is influenced by sea-surface temperature variations in the oceans. Land-surface feedback is found to increase this variability both on interannual and interdecadal time scales. Interactive vegetation enhances the interdecadal variation substantially but can reduce year-to-year variability because of a phase lag introduced by the relatively slow vegetation adjustment time. Variations in vegetation accompany the changes in rainfall, in particular the multidecadal drying trend from the 1950s to the 1980s.
540 citations
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TL;DR: Following a major upgrade, the two advanced detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) held their first observation run between September 2015 and January 2016, and observed a transient gravitational-wave signal determined to be the coalescence of two black holes.
Abstract: Following a major upgrade, the two advanced detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) held their first observation run between September 2015 and January 2016. With a strain sensitivity of $10^{-23}/\sqrt{\mathrm{Hz}}$ at 100 Hz, the product of observable volume and measurement time exceeded that of all previous runs within the first 16 days of coincident observation. On September 14th, 2015 the Advanced LIGO detectors observed a transient gravitational-wave signal determined to be the coalescence of two black holes [Phys. Rev. Lett. 116, 061102 (2016)], launching the era of gravitational-wave astronomy. The event, GW150914, was observed with a combined signal-to-noise ratio of 24 in coincidence by the two detectors. Here we present the main features of the detectors that enabled this observation. At full sensitivity, the Advanced LIGO detectors are designed to deliver another factor of three improvement in the signal-to-noise ratio for binary black hole systems similar in masses to GW150914.
539 citations
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California Institute of Technology1, Goddard Space Flight Center2, University of Bremen3, National Institute of Water and Atmospheric Research4, Woods Hole Oceanographic Institution5, University of California, Berkeley6, Harvard University7, Haverford College8, Commonwealth Scientific and Industrial Research Organisation9, Colorado State University10, Climate Monitoring and Diagnostics Laboratory11, Goodrich Corporation12
TL;DR: The Orbiting Carbon Observatory (OCO) as mentioned in this paper is the first global, space-based measurements of atmospheric carbon dioxide (CO 2 ) with the precision, resolution and coverage needed to characterize CO 2 sources and sinks on regional scales.
539 citations
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Cornell University1, Washington University in St. Louis2, Max Planck Society3, Ames Research Center4, University of Nevada, Reno5, United States Geological Survey6, Arizona State University7, Lockheed Martin Corporation8, American Museum of Natural History9, University of Chicago10, Space Science Institute11, California Institute of Technology12, Honeybee Robotics13, Smithsonian Institution14, Massachusetts Institute of Technology15, University of Mainz16, Harvard University17, Glenn Research Center18, Texas A&M University19, Ohio State University20, University of Copenhagen21, Stony Brook University22, University of Tennessee23, German Aerospace Center24, Goddard Space Flight Center25, University of Arizona26, University of Alabama at Birmingham27
TL;DR: The Mars Exploration Rover Opportunity has investigated the landing site in Eagle crater and the nearby plains within Meridiani Planum, and the rocks are interpreted to be a mixture of chemical and siliciclastic sediments formed by episodic inundation by shallow surface water, followed by evaporation, exposure, and desiccation.
Abstract: The Mars Exploration Rover Opportunity has investigated the landing site in Eagle crater and the nearby plains within Meridiani Planum. The soils consist of fine-grained basaltic sand and a surface lag of hematite-rich spherules, spherule fragments, and other granules. Wind ripples are common. Underlying the thin soil layer, and exposed within small impact craters and troughs, are flat-lying sedimentary rocks. These rocks are finely laminated, are rich in sulfur, and contain abundant sulfate salts. Small-scale cross-lamination in some locations provides evidence for deposition in flowing liquid water. We interpret the rocks to be a mixture of chemical and siliciclastic sediments formed by episodic inundation by shallow surface water, followed by evaporation, exposure, and desiccation. Hematite-rich spherules are embedded in the rock and eroding from them. We interpret these spherules to be concretions formed by postdepositional diagenesis, again involving liquid water.
538 citations
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University of British Columbia1, Princeton University2, University of KwaZulu-Natal3, University of Nottingham4, Johns Hopkins University5, University of Oxford6, Pontifical Catholic University of Chile7, Carnegie Mellon University8, University of Toronto9, Sapienza University of Rome10, Lawrence Berkeley National Laboratory11, Argonne National Laboratory12, University of Pennsylvania13, National Institute of Standards and Technology14, Rutgers University15, University of Pittsburgh16, University of California, Santa Barbara17, Cornell University18, Haverford College19, Leiden University20, West Chester University of Pennsylvania21, Goddard Space Flight Center22
TL;DR: In this paper, the authors presented a catalog of 68 galaxy clusters, of which 19 are new discoveries, detected via the Sunyaev-Zel'dovich effect (SZ) at 148 GHz in the Atacama Cosmology Telescope (ACT) survey on the celestial equator.
Abstract: We present a catalog of 68 galaxy clusters, of which 19 are new discoveries, detected via the Sunyaev-Zel'dovich effect (SZ) at 148 GHz in the Atacama Cosmology Telescope (ACT) survey on the celestial equator. With this addition, the ACT collaboration has reported a total of 91 optically confirmed, SZ detected clusters. The 504 square degree survey region includes 270 square degrees of overlap with SDSS Stripe 82, permitting the confirmation of SZ cluster candidates in deep archival optical data. The subsample of 48 clusters within Stripe 82 is estimated to be 90% complete for M{sub 500c} > 4.5 × 10{sup 14}M{sub s}un and redshifts 0.15 < z < 0.8. While a full suite of matched filters is used to detect the clusters, the sample is studied further through a ''Profile Based Amplitude Analysis'' using a statistic derived from a single filter at a fixed θ{sub 500} = 5.'9 angular scale. This new approach incorporates the cluster redshift along with prior information on the cluster pressure profile to fix the relationship between the cluster characteristic size (R{sub 500}) and the integrated Compton parameter (Y{sub 500}). We adopt a one-parameter family of ''Universal Pressure Profiles'' (UPP) with associated scaling laws, derived frommore » X-ray measurements of nearby clusters, as a baseline model. Three additional models of cluster physics are used to investigate a range of scaling relations beyond the UPP prescription. Assuming a concordance cosmology, the UPP scalings are found to be nearly identical to an adiabatic model, while a model incorporating non-thermal pressure better matches dynamical mass measurements and masses from the South Pole Telescope. A high signal to noise ratio subsample of 15 ACT clusters with complete optical follow-up is used to obtain cosmological constraints. We demonstrate, using fixed scaling relations, how the constraints depend on the assumed gas model if only SZ measurements are used, and show that constraints from SZ data are limited by uncertainty in the scaling relation parameters rather than sample size or measurement uncertainty. We next add in seven clusters from the ACT Southern survey, including their dynamical mass measurements, which are based on galaxy velocity dispersions and thus are independent of the gas physics. In combination with WMAP7 these data simultaneously constrain the scaling relation and cosmological parameters, yielding 68% confidence ranges described by σ{sub 8} = 0.829 ± 0.024 and Ω{sub m} = 0.292 ± 0.025.. We consider these results in the context of constraints from CMB and other cluster studies. The constraints arise mainly due to the inclusion of the dynamical mass information and do not require strong priors on the SZ scaling relation parameters. The results include marginalization over a 15% bias in dynamical masses relative to the true halo mass. In an extension to ΛCDM that incorporates non-zero neutrino mass density, we combine our data with WMAP7, Baryon Acoustic Oscillation data, and Hubble constant measurements to constrain the sum of the neutrino mass species to be Σ{sub ν}m{sub ν} < 0.29 eV (95% confidence limit)« less
537 citations
Authors
Showing all 19247 results
Name | H-index | Papers | Citations |
---|---|---|---|
Anton M. Koekemoer | 168 | 1127 | 106796 |
Alexander S. Szalay | 166 | 936 | 145745 |
David W. Johnson | 160 | 2714 | 140778 |
Donald G. York | 160 | 681 | 156579 |
Takeo Kanade | 147 | 799 | 103237 |
Gillian R. Knapp | 145 | 460 | 121477 |
Olaf Reimer | 144 | 716 | 74359 |
R. A. Sunyaev | 141 | 848 | 107966 |
Christopher T. Russell | 137 | 2378 | 97268 |
Hui Li | 135 | 2982 | 105903 |
Neil Gehrels | 134 | 727 | 80804 |
Christopher B. Field | 133 | 408 | 88930 |
Igor V. Moskalenko | 132 | 542 | 58182 |
William T. Reach | 131 | 535 | 90496 |
Adam Burrows | 130 | 623 | 55483 |