118 research outputs found

    The Second Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope

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    The second catalog of active galactic nuclei (AGNs) detected by the Fermi Large Area Telescope (LAT) in two years of scientific operation is presented. The Second LAT AGN Catalog (2LAC) includes 1017 gamma-ray sources located at high Galactic latitudes (|b|>10{\deg}) that are detected with a test statistic greater than 25 and associated statistically with AGNs. However some of these are affected by analysis issues and some are associated with multiple AGNs. Consequently we define a clean sample which includes 886 AGNs, comprising 395 BL Lacertae objects (BL Lacs), 310 flat-spectrum radio quasars (FSRQs), 157 candidate blazars of unknown type (i.e., with broad-band blazar characteristics but with no optical spectral measurement yet), eight misaligned AGNs, four narrow-line Seyfert 1 (NLS1s), 10 AGNs of other types and two starburst galaxies. Where possible, the blazars have been further classified based on their spectral energy distributions (SEDs) as archival radio, optical, and X-ray data permit. While almost all FSRQs have a synchrotron-peak frequency 10^14 Hz, about half of the BL Lacs have a synchrotron-peak frequency >10^15 Hz. The 2LAC represents a significant improvement relative to the First LAT AGN Catalog (1LAC), with 52% more associated sources. The full characterization of the newly detected sources will require more broad-band data. Various properties, such as gamma-ray fluxes and photon power law spectral indices, redshifts, gamma-ray luminosities, variability, and archival radio luminosities---and their correlations are presented and discussed for the different blazar classes. The general trends observed in 1LAC are confirmed.Comment: Accepted for publication in The Astrophysical Journal. 103 pages, 45 figures, 9 tables. Full tables are available at http://www.asdc.asi.it/fermi2lac

    Community-level characteristics and environmental factors of child respiratory illnesses in Southern Arizona

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    Abstract Background Lower respiratory illnesses (LRIs) and asthma are common diseases in children 0.05). Conclusions Our study revealed complex, multi-factorial associations between predictors and outcomes. Findings indicate that many rural areas with lower SES have distinct factors for childhood respiratory diseases that require further investigation. County-wide differences in maternal characteristics or agricultural land uses (not tested here) may also play a role in Pima County residence protecting against hospitalizations, when compared to Maricopa County. By better understanding this and other relationships, more focused public health interventions at the community level could be developed to reduce and better control these diseases in children <5 years, who are more physiologically vulnerable

    “Telling me not to worry…” Hyperscanning and Neural Dynamics of Emotion Processing During Guided Imagery and Music

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    To analyze how emotions and imagery are shared, processed and recognized in Guided Imagery and Music, we measured the brain activity of an experienced therapist (“Guide”) and client (“Traveler”) with dual-EEG in a real therapy session about potential death of family members. Synchronously with the EEG, the session was video-taped and then micro-analyzed. Four raters identified therapeutically important moments of interest (MOI) and no-interest (MONI) which were transcribed and annotated. Several indices of emotion- and imagery-related processing were analyzed: frontal and parietal alpha asymmetry, frontal midline theta, and occipital alpha activity. Session ratings showed overlaps across all raters, confirming the importance of these MOIs, which showed different cortical activity in visual areas compared to resting-state. MOI 1 was a pivotal moment including an important imagery with a message of hope from a close family member, while in the second MOI the Traveler sent a message to an unborn baby. Generally, results seemed to indicate that the emotions of Traveler and Guide during important moments were not positive, pleasurably or relaxed when compared to resting-state, confirming both were dealing with negative emotions and anxiety that had to be contained in the interpersonal process. However, the temporal dynamics of emotion-related markers suggested shifts in emotional valence and intensity during these important, personally meaningful moments; for example, during receiving the message of hope, an increase of frontal alpha asymmetry was observed, reflecting increased positive emotional processing. EEG source localization during the message suggested a peak activation in left middle temporal gyrus. Interestingly, peaks in emotional markers in the Guide partly paralleled the Traveler's peaks; for example, during the Guide's strong feeling of mutuality in MOI 2, the time series of frontal alpha asymmetries showed a significant cross-correlation, indicating similar emotional processing in Traveler and Guide. Investigating the moment-to-moment interaction in music therapy showed how asymmetry peaks align with the situated cognition of Traveler and Guide along the emotional contour of the music, representing the highs and lows during the therapy process. Combining dual-EEG with detailed audiovisual and qualitative data seems to be a promising approach for further research into music therapy

    Horizontal surface-slip distribution through several seismic cycles: The Eastern Bogd fault, Gobi-Altai, Mongolia

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    International audienceThe 1957, MW 8.1, Gobi-Altai earthquake, Southern Mongolia, produced a ~360-km-long surface rupture along the Eastern Bogd fault. Cumulative offsets of geomorphic features suggest that the Eastern Bogd fault might produce characteristic slip over the last seismic cycles.Using orthophotographs derived from a dataset of historical aerial photographs acquired in 1958, we measured horizontal offsets along two thirds (~170 km) of the 1957 left-lateral strike-slip surface rupture. We propose a new empirical methodology to extract the average slip for each past earthquake that could be recognized along successive fault segments, to determine the slip distribution associated with successive past earthquakes.Our results suggest that the horizontal slip distribution of the 1957 Gobi-Altai earthquake is fairly flat, with an average offset of 3.5 m ± 1.3 m. A combination of our lateral measurements with vertical displacements derived from the literature, allows us to re-assess the magnitude of the Gobi-Altai earthquake to be between MW 7.8 and MW 8.2, depending on the depth of the rupture, and related value of the shear modulus. When comparing this magnitude to magnitudes derived from seismic data, it suggests that the rupture may have extended deeper than the 15 km to 20 km usually considered for the seismogenic crust.We observe that some fault segments are more likely than others to record seismic deformation through several seismic cycles, depending on the local rupture complexity and geomorphology. Additionally, our results allow us to model the horizontal slip function for the 1957 Gobi-Altai earthquake and for three previous paleoseismic events along 70% of the studied area. Along about 50% of the fault sections where we could recognize three past earthquakes, our results suggest that the slip per event was similar for each earthquake
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