503 research outputs found
The Herschel view of the environment of the radio galaxy 4C+41.17 at z = 3.8
We present Herschel observations at 70, 160, 250, 350 and 500 μm of the environment of the radio galaxy 4C+41.17 at z = 3.792. About 65 per cent of the extracted sources are securely identified with mid-infrared sources observed with the Spitzer Space Telescope at 3.6, 4.5, 5.8, 8 and 24 μm. We derive simple photometric redshifts, also including existing 850 and 1200 μm data, using templates of active galactic nuclei, starburst-dominated systems and evolved stellar populations. We find that most of the Herschel sources are foreground to the radio galaxy and therefore do not belong to a structure associated with 4C+41.17. We do, however, find that the spectral energy distribution (SED) of the closest (∼25 arcsec offset) source to the radio galaxy is fully consistent with being at the same redshift as 4C+41.17. We show that finding such a bright source that close to the radio galaxy at the same redshift is a very unlikely event, making the environment of 4C+41.17 a special case. We demonstrate that multiwavelength data, in particular on the Rayleigh–Jeans side of the SED, allow us to confirm or rule out the presence of protocluster candidates that were previously selected by single wavelength data setsPeer reviewe
Manageable creativity
This article notes a perception in mainstream management theory and practice that creativity has shifted from being disruptive or destructive to 'manageable'. This concept of manageable creativity in business is reflected in a similar rhetoric in cultural policy, especially towards the creative industries. The article argues that the idea of 'manageable creativity' can be traced back to a 'heroic' and a 'structural' model of creativity. It is argued that the 'heroic' model of creativity is being subsumed within a 'structural' model which emphasises the systems and infrastructure around individual creativity rather than focusing on raw talent and pure content. Yet this structured approach carries problems of its own, in particular a tendency to overlook the unpredictability of creative processes, people and products. Ironically, it may be that some confusion in our policies towards creativity is inevitable, reflecting the paradoxes and transitions which characterise the creative process
Acute Conjunctivitis with Episcleritis and Anterior Uveitis Linked to Adiaspiromycosis and Freshwater Sponges, Amazon Region, Brazil, 2005
An epidemiologic investigation of an ocular disease outbreak among children was linked to the unusual fungus Emmonsia sp., an agent of adiaspiromycosis
New insights into the role of AGNs in forming the cluster red sequence
As a considerable investment of time from various telescope facilities was dedicated toward studying the Spiderweb protocluster at z = 2.2, it so far remains one of the most extensively studied protocluster. We report here the latest results in this field, adding a new dimension to previous research on cluster formation at high redshift. Previous studies have reported a significant overdensity (δ ∼ 10) of massive Hα (+ [N ii])-emitting galaxies in 3700 comoving Mpc3. Many of these were previously considered to be dusty, actively star-forming galaxies, given their rest-frame optical and infrared features. However, this study argues that a third of them are more likely to be ‘passively evolving’ galaxies with low-luminosity active galactic nuclei (AGNs) rather than star-forming galaxies, given the multiwavelength spectral energy distribution (SED) fitting including an AGN component. For their SED-based star formation rates to be valid, bulk of their Hα + [N ii] emission should come from the central AGNs. This difference in interpretation between this work and past studies, including ours, is particularly supported by the recent deep Chandra/X-ray observation. Furthermore, we have spectroscopically confirmed a quiescent nature for one of these AGNs, with its multiple stellar absorption lines but also low-ionization emission lines. This important update provides new insights into the role of AGNs in forming the cluster red sequence observed in the present-day universe
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Instrumentation and Measurement Strategy for the NOAA SENEX Aircraft Campaign as Part of the Southeast Atmosphere Study 2013
Natural emissions of ozone-and-aerosol-precursor gases such as isoprene and monoterpenes are high in the southeast of the US. In addition, anthropogenic emissions are significant in the Southeast US and summertime photochemistry is rapid. The NOAA-led SENEX (Southeast Nexus) aircraft campaign was one of the major components of the Southeast Atmosphere Study (SAS) and was focused on studying the interactions between biogenic and anthropogenic emissions to form secondary pollutants. During SENEX, the NOAA WP-3D aircraft conducted 20 research flights between 27 May and 10 July 2013 based out of Smyrna, TN. Here we describe the experimental approach, the science goals and early results of the NOAA SENEX campaign. The aircraft, its capabilities and standard measurements are described. The instrument payload is summarized including detection limits, accuracy, precision and time resolutions for all gas-and-aerosol phase instruments. The inter-comparisons of compounds measured with multiple instruments on the NOAA WP-3D are presented and were all within the stated uncertainties, except two of the three NO2 measurements. The SENEX flights included day- and nighttime flights in the Southeast as well as flights over areas with intense shale gas extraction (Marcellus, Fayetteville and Haynesville shale). We present one example flight on 16 June 2013, which was a daytime flight over the Atlanta region, where several crosswind transects of plumes from the city and nearby point sources, such as power plants, paper mills and landfills, were flown. The area around Atlanta has large biogenic isoprene emissions, which provided an excellent case for studying the interactions between biogenic and anthropogenic emissions. In this example flight, chemistry in and outside the Atlanta plumes was observed for several hours after emission. The analysis of this flight showcases the strategies implemented to answer some of the main SENEX science questions
Prototyping Self in Silicon Valley, Deep Diversity as a Framework for Anthropological Inquiry
High-technology work fuels a dynamic global exchange from technopoles throughout the world, but especially between East and South Asia and the northern Californian region of Silicon Valley. This migration drives an expanded number of ancestral identities. Professional and activity-based identities flourish as Silicon Valley’s strong narrative of meritocracy loosens the grip of birth ascription on the creation of identities. These achieved identities proliferate as people experiment on their own sense of self. Traditional conceptual tools related to immigration, and even such contemporary approaches as Appadurai’s ethnoscapes, do not adequately illuminate the ethnographic data on Silicon Valley workers, families, and especially youth. The concept of deep diversity, first posed by philosopher Charles Taylor and reified by anthropologist Clifford Geertz, reinterprets the interactions of traditional ethnic identity categories, providing a powerful framework with which to think
MAHALO Deep Cluster Survey II. Characterizing massive forming galaxies in the Spiderweb protocluster at z = 2.2
This paper is the second in a series presenting the results of our deep H α-line survey towards protoclusters at z > 2, based on narrow-band imaging with the Subaru Telescope. This work investigates massive galaxies in a protocluster region associated with a radio galaxy (PKS 1138 − 262), the Spiderweb galaxy, at z = 2.2. Our 0.5 mag deeper narrow-band imaging than previous surveys collects a total of 68 H α emitters (HAE). Here, 17 out of the 68 are newly discovered protocluster members. First, a very high characteristic stellar mass of M∗⋆=1011.73 M⊙ is measured from a Schechter function fit to the mass distribution of HAEs. Together with the Chandra X-ray data, we find that four out of six massive HAEs (M⋆ > 1011 M⊙) show bright X-ray emission, suggesting that they host active galactic nuclei (AGNs). Their mass estimates, therefore, would be affected by the nuclear emission from AGNs. Notably, the X-ray-detected HAEs are likely positioned near the boundary between star-forming and quiescent populations in the rest-frame UVJ plane. Moreover, our deep narrow-band data succeed in probing the bright H α (+ [N ii]) line nebula of the Spiderweb galaxy extending over ∼100 physical kpc. These results suggest that the massive galaxies in the Spiderweb protocluster are on the way to becoming the bright red sequence objects seen in local galaxy clusters, where AGNs might play an essential role in their quenching processes, though a more statistical database is needed to build a general picture
Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS
We present the results of a search for new, heavy particles that decay at a
significant distance from their production point into a final state containing
charged hadrons in association with a high-momentum muon. The search is
conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV
and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS
detector operating at the Large Hadron Collider. Production of such particles
is expected in various scenarios of physics beyond the standard model. We
observe no signal and place limits on the production cross-section of
supersymmetric particles in an R-parity-violating scenario as a function of the
neutralino lifetime. Limits are presented for different squark and neutralino
masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final
version to appear in Physics Letters
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS
The chi_b(nP) quarkonium states are produced in proton-proton collisions at
the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS
detector. Using a data sample corresponding to an integrated luminosity of 4.4
fb^-1, these states are reconstructed through their radiative decays to
Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks
corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new
structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is
also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes.
This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table,
corrected author list, matches final version in Physical Review Letter
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