Gamma-Ray and Parsec-Scale Jet Properties of a Complete Sample of Blazars From the MOJAVE Program

We investigate the Fermi LAT gamma-ray and 15 GHz VLBA radio properties of a joint gamma-ray- and radio-selected sample of AGNs obtained during the first 11 months of the Fermi mission (2008 Aug 4 - 2009 Jul 5). Our sample contains the brightest 173 AGNs in these bands above declination -30 deg. during this period, and thus probes the full range of gamma-ray loudness (gamma-ray to radio band luminosity ratio) in the bright blazar population. The latter quantity spans at least four orders of magnitude, reflecting a wide range of spectral energy distribution (SED) parameters in the bright blazar population. The BL Lac objects, however, display a linear correlation of increasing gamma-ray loudness with synchrotron SED peak frequency, suggesting a universal SED shape for objects of this class. The synchrotron self-Compton model is favored for the gamma-ray emission in these BL Lacs over external seed photon models, since the latter predict a dependence of Compton dominance on Doppler factor that would destroy any observed synchrotron SED peak - gamma-ray loudness correlation. The high-synchrotron peaked (HSP) BL Lac objects are distinguished by lower than average radio core brightness temperatures, and none display large radio modulation indices or high linear core polarization levels. No equivalent trends are seen for the flat-spectrum radio quasars (FSRQ) in our sample. Given the association of such properties with relativistic beaming, we suggest that the HSP BL Lacs have generally lower Doppler factors than the lower-synchrotron peaked BL Lacs or FSRQs in our sample.Comment: 22 pages, 11 figures, 4 tables; accepted for publication in the Astrophysical Journa

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Multi-messenger Observations of a Binary Neutron Star Merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ∼ 1.7 {{s}} with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of {40}-8+8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 {M}ȯ . An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ∼ 40 {{Mpc}}) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ∼ 9 and ∼ 16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta.</p

Per Se Legality in Copyright Licensing

There is an inherent tension between the law of antitrust and the law of copyright. While the former prevents monopolies, the latter creates them. In order to reconcile this conflict the author suggests application of a rule of per se legality to exclusive territorial licenses of copyrighted works. Such an approach would provide copyright holders with a certain legal standard, not now available under the indefinite Rule of Reason. The author argues that there is authority for such a rule of per se legality based on the Copyright Act of 1976, precedent in patent law and the concept of copyright itself

The extraordinarily strong and cold polar vortex in the early northern winter 2015/16

The Arctic polar vortex in the early winter 2015/16 was the strongest and coldest o f the la st 68 years. Using global reanalysis data, satellite observations, and mesospheric radar wind measurements over northern Scandinavia we investigate the characteristics of the early sta g e polar vortex and relate them to previous winters. We found a correlation between the planetary wave (PW) activity and the strength and temperature of the northern polar vor- tex in the stratosphere and mesosphere. In Nov/D ec 2015, a reduced PW generation in the troposphere and a stronger PW filtering in the troposphere and stratosphere, caused by stronger zonal winds in mid-latitudes, resulted in a stronger polar vortex. Thi s effect was strengthened by the equator ward shift of PWs due to the strong zonal wind in polar latitudes resulting in a southward shift of the Eliassen-Palm flux divergence and hence inducinga decreased deceleration of th e polar vortex by PWs

Health and demography of native Amazonians: historical perspective and current status Saúde e demografia de povos indígenas amazônicos: perspectiva histórica e situação atual

Native Amazonians have been the victims of two massive historical assaults, one at the time of the Conquest and the other during the Twentieth century. Due to epidemic disease and environmental destruction, many tribes have gone from contact to displacement, decimation, and extinction in a single generation. Deculturation and the construction of large development projects have had catastrophic effects on native populations. In many ways, native Amazonians have experienced a reverse of the "Epidemiologic Transition". Paradoxically, one of the effects of cultural disruption for some native Amazonians has been the loss of cultural controls on fertility with the result that high fertility has become a major health problem. Combined with rapid growth of non-indigenous Amazonian populations, deforestation, and urbanization, native Amazonians face grave obstacles to long-term survival.<br>Os nativos da Amazônia foram vítimas de dois grandes ataques históricos: um na época da Conquista e outro durante o século XX. Devido a doenças epidêmicas e à destruição ambiental, inúmeras tribos passaram a vivenciar problemas de deslocamentos, dizimação e extinção em uma única geração. A aculturação e a construção de grandes projetos desenvolvimentistas tiveram efeitos catastróficos sobre as populações indígenas. Em diversos aspectos, os nativos da Amazônia sofreram uma "Transição Epidemiológica". Paradoxalmente, um dos efeitos da dilaceração cultural para alguns dos nativos da Amazônia foi a perda de controles culturais sobre a fecundidade, fazendo com que a elevada fecundidade se tornasse um importante problema de saúde. Com o rápido crescimento de populações amazônicas não indígenas, o desmatamento e a urbanização, os nativos da Amazônia enfrentam sérios obstáculos para a sua sobrevivência a longo prazo