949 research outputs found
Deployable lattice column
Lattice column, made up of many individually collapsible sections connected in tandem, rapidly raises measuring instruments to a level appreciably above that where data is to be recorded and evaluated. The column may be collapsed by collapsing each section in sequence and is deployed by extending each section in sequence
Optimum design of columns supported by tension ties
Optimum design of thin walled cylindrical columns supported by tension tie
Radio sources with ultra-high polarization
A sample of 129 unresolved radio sources with ultrahigh linear polarization
(>30 per cent) has been selected from the NRAO VLA Sky Survey. Such high
average linear polarization is unusual in extragalactic sources. Higher
resolution Australia Telescope Compact Array and Very Large Array observations
confirm the high average polarization but find that most of these sources are
extended. The Sloan Digital Sky Survey spectroscopy, where available, shows
that the optical counterparts are elliptical galaxies with no detectable
emission lines. The optical spectra, radio luminosity, linear size and spectral
index of these sources are typical of radio-loud active galactic nuclei. Galaxy
counts within a 1 Mpc radius of the radio sources show that these highly
polarized sources are in environments similar to their low polarization (<2 per
cent) counterparts. Similarly, the line-of-sight environments of the ultrahigh
polarization sources are on average indistinguishable from those of the
low-polarization sources. We conclude that the extraordinarily high average
polarization must be due to intrinsic properties of the sources, such as an
extremely ordered source magnetic field, low internal thermal plasma density or
a preferential orientation of the source magnetic field perpendicular to the
line of sight.Comment: 23 pages, 15 figures, 6 tables, accepted for publication in MNRAS;
v2: some typos correcte
The Stripe 82 1-2 GHz Very Large Array Snapshot Survey: Multiwavelength Counterparts
We have combined spectrosopic and photometric data from the Sloan Digital Sky
Survey (SDSS) with GHz radio observations, conducted as part of the
Stripe 82 GHz Snapshot Survey using the Karl G. Jansky Very Large Array
(VLA), which covers sq degrees, to a flux limit of 88 Jy rms.
Cross-matching the radio source components with optical data via
visual inspection results in a final sample of cross-matched objects,
of which have spectroscopic redshifts and objects have
photometric redshifts. Three previously undiscovered Giant Radio Galaxies
(GRGs) were found during the cross-matching process, which would have been
missed using automated techniques. For the objects with spectroscopy we
separate radio-loud Active Galactic Nuclei (AGN) and star-forming galaxies
(SFGs) using three diagnostics and then further divide our radio-loud AGN into
the HERG and LERG populations. A control matched sample of HERGs and LERGs,
matched on stellar mass, redshift and radio luminosity, reveals that the host
galaxies of LERGs are redder and more concentrated than HERGs. By combining
with near-infrared data, we demonstrate that LERGs also follow a tight
relationship. These results imply the LERG population are hosted by population
of massive, passively evolving early-type galaxies. We go on to show that
HERGs, LERGs, QSOs and star-forming galaxies in our sample all reside in
different regions of a WISE colour-colour diagram. This cross-matched sample
bridges the gap between previous `wide but shallow' and `deep but narrow'
samples and will be useful for a number of future investigations.Comment: 17 pages, 19 figures. Resubmitted to MNRAS after the initial comment
SUMSS: A Wide-Field Radio Imaging Survey of the Southern Sky. II. The Source Catalogue
This paper is the second in a series describing the Sydney University
Molonglo Sky Survey (SUMSS) being carried out at 843MHz with the Molonglo
Observatory Synthesis Telescope (MOST). The survey will consist of ~590 4.3deg.
x 4.3deg. mosaic images with 45"x45"cosec|dec.| resolution, and a source
catalogue. In this paper we describe the initial release (version 1.0) of the
source catalogue consisting of 107,765 radio sources made by fitting elliptical
gaussians in 271 SUMSS mosaics to a limiting peak brightness of 6mJy/beam at
dec.-50deg.. The catalogue covers
approximately 3500deg^2 of the southern sky with dec.<=-30deg., about 43 per
cent of the total survey area. Positions in the catalogue are accurate to
within 1"-2" for sources with peak brightness A>=20mJy/beam and are always
better than 10". The internal flux density scale is accurate to within 3 per
cent. Image artefacts have been classified using a decision tree, which
correctly identifies and rejects spurious sources in over 96 per cent of cases.
Analysis of the catalogue shows that it is highly uniform and is complete to
8mJy at dec.-50deg.. In this release of the
catalogue about 7000 sources are found in the overlap region with the NRAO VLA
Sky Survey (NVSS) at 1.4GHz. We calculate a median spectral index of
alpha=-0.83 between 1.4GHz and 843MHz. This version of the catalogue will be
released via the World Wide Web with future updates as new mosaics are
released.Comment: 15 pages, 15 figures, accepted by MNRAS, Catalogue at
http://www.astrop.physics.usyd.edu.au/sumssca
Eficiência de controle de extratos alcoólicos obtidos de plantas nativas do Rio Grande do Sul aplicados em adultos de Diabrotica speciosa.
Nuclear Activity of MLA Immune Receptors Links Isolate-Specific and Basal Disease-Resistance Responses
Psychiatric disorder as clinical presentation of primary Sjögren's syndrome: two case reports
Psychiatric disorders in primary Sjögren's syndrome constitute a possible clinical reality that each practitioner must be able to recognise and treat. In this article, two case reports of mental disorder as clinical presentation of primary Sjögren's syndrome are presented, suggesting that psychiatric manifestations in primary Sjögren's syndrome can occur not only during its longitudinal course, but also at the onset of the autoimmune syndrome. A better adapted prescription of corticosteroids and/or immunosuppressive agents (together with specific psychotropic treatments) can induce rapid relief of mental symptoms
- …