808 research outputs found
Structure of the magnetoionic medium around the FR Class I radio galaxy 3C 449
The goal of this work is to constrain the strength and structure of the
magnetic field associated with the environment of the radio source 3C 449,
using observations of Faraday rotation, which we model with a structure
function technique and by comparison with numerical simulations. We assume that
the magnetic field is a Gaussian, isotropic random variable and that it is
embedded in the hot intra-group plasma surrounding the radio source. For this
purpose, we present detailed rotation measure images for the polarized radio
source 3C 449, previously observed with the Very Large Array at seven
frequencies between 1.365 and 8.385 GHz. We quantify the statistics of the
magnetic-field fluctuations by deriving rotation measure structure functions,
which we fit using models derived from theoretical power spectra. We quantify
the errors due to sampling by making multiple two-dimensional realizations of
the best-fitting power spectrum.We also use depolarization measurements to
estimate the minimum scale of the field variations. We then make
three-dimensional models with a gas density distribution derived from X-ray
observations and a random magnetic field with this power spectrum. Under these
assumptions we find that both rotation measure and depolarization data are
consistent with a broken power-law magnetic-field power spectrum, with a break
at about 11 kpc and slopes of 2.98 and 2.07 at smaller and larger scales
respectively. The maximum and minimum scales of the fluctuations are around 65
and 0.2 kpc, respectively. The average magnetic field strength at the cluster
centre is 3.5 +/-1.2 micro-G, decreasing linearly with the gas density within
about 16 kpc of the nucleus.Comment: 19 pages; 14 figures; accepted for publication on A&A. For a high
quality version use ftp://ftp.eso.org/pub/general/guidetti
Woefully Arrayed: Sacred and Secular Choral and Polychoral Works of Jonathan David Little (b.1965) ["Woefully Arrayed", Op.13; "Kyrie", Op.5; "Gloria", Op.18; âWasted and Wornâ, Op.6; âThat Time of Year", Op.2]
âA music redolent of the past and the futureâ
Several of the works in this collection feature intricate, a cappella, polychoral-inspired techniques. These include multi-part, multi-divisi, and unusual spatial effects (or cori spezzati â literally âsplit choirsâ â as the technique was referred to in the Renaissance and early Baroque periods). Therefore different sections of the choir, or different âsub-choirsâ and/or vocal soloists, are sometimes placed in various arrangements around and above the audience: this ancient technique being pioneered in modern form in âKyrieâ, Op.5, for 21 individual vocal lines â where some singers are stationed in a gallery, and at a distance. Some works also feature echo effects, as well as isorhythmic fragments, melodic and rhythmic hocket, while cross-rhythms and cross-textuality may additionally be involved.
Due to the incorporation of such âpolychoralâ-derived techniques (in addition to some derived from Medieval music), a striking extra dimension is added both to recordings and to live performances (where the aural âspatialâ interest creates a quasi-theatrical effect). The harmonic language is largely built on the composerâs personalised modal foundations, frequently complemented by very subtle use of rhythm and ornament, which can sometimes involve quite elaborate â but always delicate â âfiligreeâ-like patterns.
All but the Kyrie are world premiĂšre recordings (including the first recording of the choral version of That Time of Year), and were recorded over five separate sessions in the UK and US.
Includes an additional historical and contextual essay by Renaissance and Baroque scholar, Hugh Keyte, leading expert on early polychoralism: "Polychorality: Some Observations".
(NOTE: Opus numbers in the composerâs Ćuvre are apportioned according to date of initial conception, rather than by date of completion.)
âWOEFULLY ARRAYEDâ:
Sacred and Secular Choral and Polychoral Works of JONATHAN DAVID LITTLE (b.1965)
INCLUDES WORLD PREMIĂRE RECORDINGS
Vox Futura, Boston (USA)
Directed by Andrew Shenton; Organ: Heinrich Christensen
âĄStanbery Singers, Cincinnati (USA)
Directed by Paul John Stanbery
â Thomas Tallis Society Choir, Greenwich (UK)
Directed by Philip Simms
SACRED WORKS:
1. âWoefully Arrayedâ, Op.13 (Anthem for Triple Choir: AATTBB + SSA + SSA) [attrib. to John Skelton] (with Organ) (ca.26:00)
2. â Kyrie, Op.5 (SATB Double Choir with Soloists) (from Missa Temporis Perditi) (ca.4:50)
* * * ROYAL PHILHARMONIC SOCIETY / BBC RADIO 3 âENCORE Choralâ Award Winner * * *
3. Gloria, Op.18 (SATB Double Choir with Soloists) (from Missa Temporis Perditi) (ca.12:00)
SECULAR WORKS:
4. âĄâWasted and Wornâ, Op.6 (Part Song for SSAATTBB Choir with Soloists) [Lord de Tabley] (ca.12:10)
5. âĄâThat Time of Yearâ, Op.2 (SATBarB Choir) [Shakespeare] (ca.4:45)
6. âWoefully Arrayedâ, Op.13 [Reprise â abridged version] (ca.12:30)
This project has been assisted by the Australian Government through the Australia Council for the Arts, its arts funding and advisory body (Individual International Arts Project Award 2015-17: UK-USA-Australia). Invaluable support has also been provided by the Royal Philharmonic Society (UK), through its âENCORE Choralâ Award scheme.
The support and advice of music publishers Anne Keats, OAM, and Brennan Keats, OAM, Directors of Wirripang Pty Ltd (Australia), of Ben Hall and staff at the University of Chichester (UK), of Professor Craig De Wilde of the University of Singapore, of music copyist David Turner (UK), of Bob Lord and all his team at PARMA Recordings (USA), and of James M. Kendrick (Director and Treasurer of ASCAP, USA), is gratefully acknowledged
Multifrequency Study of The Radio Galaxy NGC326
We present the results of a multi-frequency study of the inversion symmetric
radio galaxy NGC326 based on Very Large Array observations at 1.4, 1.6, 4.8,
8.5 and 14.9 GHz. The morphological, spectral and polarization properties of
this peculiar object are studied at different levels of spatial resolutions.
The interpretation of the data will be discussed in forthcoming papers.Comment: 15 pages, 15 ps figures, accepted by A&
Radio morphology and spectral analysis of cD galaxies in rich and poor galaxy clusters
We present a radio morphological study and spectral analysis for a sample of
13 cD galaxies in rich and poor clusters of galaxies.} Our study is based on
new high sensitivity Giant Metrewave Radio Telescope (GMRT) observations at
1.28 GHz, 610 MHz and 235 MHz, and on archival data. From a statistical sample
of cluster cD galaxies we selected those sources with little information
available in the literature and promising for the detection of aged radio
emission. Beyond the high sensitivity images for all 13 radio galaxies, we
present also a detailed spectral analysis for 7 of them. We found a variety of
morphologies and linear sizes, as typical for radio galaxies in the radio power
range sampled here (low to intermediate power radio galaxies). The spectral
analysis shows that 10/13 radio galaxies have steep radio spectrum, with
spectral index . In general, the radiative ages and growth
velocities are consistent with previous findings that the evolution of radio
galaxies at the cluster centres is affected by the dense external medium (i.e.
low growth velocities and old ages. We suggest that the dominant galaxies in A
2622 and MKW 03s are dying radio sources, which at present are not fed by
nuclear activity. On the other hand, the spectacular source at the centre of A
2372 might be a very interesting example of restarted radio galaxy. For this
source we estimated a life cycle of the order of 10 yr.Comment: Accepted by A&A, 25 pages, 28 figures, 6 tables and appendix Full
version including high quality images available at
http://www.ira.inaf.it/~tventuri/pap/Venturi.pd
The ATESP 5 GHz radio survey. II. Physical properties of the faint radio population
One of the most debated issues about sub-mJy radio sources, which are
responsible for the steepening of the 1.4 GHz source counts, is the origin of
their radio emission. Particularly interesting is the possibility of combining
radio spectral index information with other observational properties to assess
whether the sources are triggered by star formation or nuclear activity. The
aim of this work is to study the optical and near infrared properties of a
complete sample of 131 radio sources with S>0.4 mJy, observed at both 1.4 and 5
GHz as part of the ATESP radio survey. We use deep multi-colour (UBVRIJK)
images, mostly taken in the framework of the ESO Deep Public Survey, to
optically identify and derive photometric redshifts for the ATESP radio
sources. Deep optical coverage and extensive colour information are available
for 3/4 of the region covered by the radio sample. Typical depths of the images
are U~25, B~26, V~25.4, R~25.5, I~24.3, 19.5<K_s<20.2, J<22.2. Optical/near
infrared counterparts are found for ~78% (66/85) of the radio sources in the
region covered by the deep multi-colour imaging, and for 56 of these reliable
estimates of the redshift and type are derived. We find that many of the
sources with flat radio spectra are characterised by high radio-to-optical
ratios (R>1000), typical of classical powerful radio galaxies and quasars.
Flat-spectrum sources with low R values are preferentially identified with
early type galaxies, where the radio emission is most probably triggered by
low-luminosity active galactic nuclei. Considering both early type galaxies and
quasars as sources with an active nucleus, such sources largely dominate our
sample (78%). Flat-spectrum sources associated with early type galaxies are
quite compact (d<10-30 kpc), suggesting core-dominated radio emission.Comment: 15 pages, 13 figures, accepted for pubblication in A&
X-ray-emitting Atmospheres of B2 Radio Galaxies
We report ROSAT PSPC spatial and spectral analysis of the eight B2 radio
galaxies NGC 315, NGC 326, 4C 35.03, B2 0326+39, NGC 2484, B2 1040+31, B2
1855+37, and 3C 449, expected to be representative of the class of low-power
radio galaxies. Multiple X-ray components are present in each, and the gas
components have a wide range of linear sizes and follow an extrapolation of the
cluster X-ray luminosity/temperature correlation, implying that there is no
relationship between the presence of a radio galaxy and the gas fraction of the
environment. No large-scale cooling flows are found. There is no correlation of
radio-galaxy size with the scale or density of the X-ray atmosphere. This
suggests that it is processes on scales less than those of the overall gaseous
environments which are the major influence on radio-source dynamics. The
intergalactic medium is usually sufficient to confine the outer parts of the
radio structures, in some cases even to within 5 kpc of the core. In the case
of NGC 315, an extrapolation suggests that the pressure of the atmosphere may
match the minimum pressure in the radio source over a factor of about 40 in
linear size (a factor of about 1600 in pressure).Comment: 34 pages, including 10 figures, using aasms4.sty To appear in the Ap
The ATESP Radio Survey II. The Source Catalogue
This paper is part of a series reporting the results of the Australia
Telescope ESO Slice Project (ATESP) radio survey obtained at 1400 MHz with the
Australia Telescope Compact Array (ATCA) over the region covered by the ESO
Slice Project (ESP) galaxy redshift survey. The survey consists of 16 radio
mosaics with ~8"x14" resolution and uniform sensitivity (1sigma noise level ~79
microJy) over the whole area of the ESP redshift survey (~26 sq. degrees at
decl. -40 degr). Here we present the catalogue derived from the ATESP survey.
We detected 2960 distinct radio sources down to a flux density limit of ~0.5
mJy (6sigma), 1402 being sub-mJy sources. We describe in detail the procedure
followed for the source extraction and parameterization. The internal accuracy
of the source parameters was tested with Monte Carlo simulations and possible
systematic effects (e.g. bandwidth smearing) have been quantified.Comment: 14 pages, 14 Postscript figures, Accepted for publication in A&A
Suppl. Corrected typos and added Journal Referenc
Studi Kecermatan Alat Ukur Kebulatan (Roundness Tester Mechine) Produksi Laboratorium Pengukuran Universitas Riau
Accuracy is the closeness or the accuracy of the measurement results with the actual value. Accuracy can also mean a measure of the closeness results of the analysis of the actual invitation analyte levels. Accuracy is vital that must be fulfilled and owned by any measurement tool, use the measuring instrument that has high accuracy and good will produce accurate measurement data and other wise use measuring devices are not accurate, do not meet the standards of the results obtained will not be accurate. This study aims to determine the value of the mandrel roundness deviation, roundness accuracy Measuring Equipment (Roundness Tester Machine) and large deviations in the roundness measuring instrument (Roundness TesterMachine) (instrument error) and the operator or gauges (human error). From the results, the large stroundness deviation value for minimum circumscribed circle is 0,474 mm, maximum inscribed circle 0,417 mm, minimum zone circle 0,495 mm, least squares circle 0,207 mm, for the value of sphericity (roundness) for the smallest outer for minimum circumscribed circleis 0,003 mm, maximum inscribed circle 0,003 mm, minimum zone circle is 0,003 mm, least squares is 0,001 mm. Value accuracy roundness measuring instrument (Roundness TesterMachine) in position 1 = 0,006 mm, position 2 = 0,006 mm, position 3 = 0,011 mm, position 4 = 0,018 mm, position 5 = 0,003 mm, position 6 = 0,018 mm, position 7 = 0,021 mm, position 8 = 0,031 mm, position 9 = 0,002 mm, position 10 = 0,001 mm and error measuring instrument (instrument error) is the largest 0,02944 mm or 18,871% and the smallest deviation is 0,00029 mm or 0,225%. Operator error or measuring (Human Error) for first test (human) 22%, second test 5,33%, third test 182%, fourth test 187%, fifth test 58%
Thermal Conductivity of Structural Glass/Fibre Epoxy Composite as a Function of Fibre Orientation
The LHC, the new superconducting particle accelerator presently under construction at CERN, makes use of some 1200 dipole magnets for orbit bending and 500 quadrupole magnets for focusing/defocusing of the circulating high-energy proton beams. Two or three column-type support posts sustain each cryomagnet. The choice of a convenient material for these supports is critical, because of the required high positioning accuracy of the magnets in their cryostats and stringent thermal budget requirements imposed by the LHC cryogenic system. A glass-fibre/epoxy resin composite has been chosen for its good combination of high stiffness and low thermal conductivity over the 2-293 K temperature range. Plies of long glass-fibres are stacked optimally yielding the best mechanical behaviour. However, heat leaks from the supports are influenced by the thermal characteristics of the composite, which in turn depend on the orientation of the fibres. To study the dependence of the thermal conductivity on fibre's orientation, we performed high precision thermal conductivity measurements of various samples of glass-fibre/epoxy resin composite. The results of the thermal conductivity measurements are compared with integral measurements on support posts for LHC cryomagnets and with mixing models
Body odors (even when masked) make you more emotional: behavioral and neural insights
Morality evolved within specific social contexts that are argued to shape moral choices. In turn, moral choices are hypothesized to be affected by body odors as they powerfully convey socially-relevant information. We thus investigated the neural underpinnings of the possible body odors effect on the participants\u2019 decisions. In an fMRI study we presented to healthy individuals 64 moral dilemmas divided in incongruent (real) and congruent (fake) moral dilemmas, using different types of harm (intentional: instrumental dilemmas, or inadvertent: accidental dilemmas). Participants were required to choose deontological or utilitarian actions under the exposure to a neutral fragrance (masker) or body odors concealed by the same masker (masked body odor). Smelling the masked body odor while processing incongruent (not congruent) dilemmas activates the supramarginal gyrus, consistent with an increase in prosocial attitude. When processing accidental (not instrumental) dilemmas, smelling the masked body odor activates the angular gyrus, an area associated with the processing of people\u2019s presence, supporting the hypothesis that body odors enhance the saliency of the social context in moral scenarios. These results suggest that masked body odors can influence moral choices by increasing the emotional experience during the decision process, and further explain how sensory unconscious biases affect human behavior
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