3,493 research outputs found
ISO observations of a sample of Compact Steep Spectrum and GHz Peaked Spectrum Radio Galaxies
We present results from observations obtained with ISOPHOT, on board the ISO
satellite, of a representative sample of seventeen CSS/GPS radio galaxies and
of a control sample of sixteen extended radio galaxies spanning similar ranges
in redshift (0.2 = 10^26 W/Hz).
The observations have been performed at lambda = 60, 90, 174 and 200 microns.
Seven of the CSS/GPS sources have detections >= 3 sigma at one or more
wavelengths, one of which is detected at >= 5 sigma. By co-adding the data we
have obtained average flux densities at the four wavelengths. We found no
evidence that the FIR luminosities of the CSS/GPS sources are significantly
different from those of the extended objects and therefore there is not any
support for CSS/GPS sources being objects "frustrated" by an abnormally dense
ambient medium. The two samples were then combined, providing FIR information
on a new sample of radio galaxies at intermediate redshifts. We compare this
information with what previously known from IRAS and discuss the average
properties of radio galaxies in the redshift range 0.2 - 0.8. The FIR emission
cannot be accounted for by extrapolation of the synchrotron radio spectrum and
we attribute it to thermal dust emission. The average FIR luminosity is >=
6*10^11 L_sun. Over the observed frequency range the infrared spectrum can be
described by a power law with spectral index alpha >~1.0 +/- 0.2. Assuming the
emission to be due to dust, a range of temperatures is required, from >=80 K to
\~25 K. The dust masses required to explain the FIR emission range from 5*10^5
M_sun for the hotter component up to 2*10^8 M_sun for the colder one.
(abridged)Comment: Astronomy & Astrophysics, in press, 16 pages, 2 Figure
Generalized Assisted Inflation
We obtain a new class of exact cosmological solutions for multi-scalar fields
with exponential potentials. We generalize the assisted inflation solutions
previously obtained, and demonstrate how they are modified when there exist
cross-couplings between the fields, such as occur in supergravity inspired
cosmological models.Comment: 5 page
Single glycine deletion in COL7A1 acting as glycine substitution in dystrophic epidermolysis bullosa
Presidential History
News release announces the Presidential History of the University of Dayton
Qualitative Modelling in Embodiment Design - Investigating the Contact and Channel Approach Through Analysis of Projects
Purposeful qualitative modelling of embodiment function relations is a challenge in embodiment design. This contribution investigates the applicability and usefulness of the Contact and Channel Approach as a qualitative modelling approach in a survey study. From 23 development and research projects, advantages and challenges regarding applicability and usefulness are identified. A further result is that many different models are used additionally to the Contact and Channel Approach. Based on the findings, research potential for optimization and development of links to other models emerges
Adaptive optics imaging and integral field spectroscopy of APM 08279+5255: Evidence for gravitational lensing
We report observations of the z = 3.87 broad absorption line quasar APM 08279+5255 (Irwin et al. 1998) with the Adaptive Optics Bonnette (AOB) of the Canada-France-Hawaii Telescope. The object is found to be a double source. The separation of the two images is 0.35" +/- 0.02" and the intensity ratio I_{north}/I_{south} = 1.21 +/- 0.25 in the H-band. No other image is detected down to H(5sigma) = 21.3 within 10" from the double image. Strong support for the lensing hypothesis comes from the uniformity of the quasar spectrum as a function of spatial position in the image obtained with the integral field spectrograph OASIS at CFHT. From the 2D-spectroscopy, narrow-band images are reconstructed over the wavelength range 5600-6200A to search for emission-line objects in a field of 15"x12" around the quasar. We find no such object to a limit of 6x10^{-17} erg cm^{-2} s^{-1}. We use the images centered on the deepest absorption lines of the Ly-alpha forest to dim the quasar and to increase the sensitivity closer to the line of sight. One of the images, centered at 5766.4A, exhibits a 3sigma excess 1.5" from the quasar to the north-east
Caracterização tecnológica e aptidão mercadológica de clones de lima ácida 'Tahiti'.
A produção nacional de lima ácida Tahiti (Citrus latifolia Tanaka) possui três mercados bastante distintos: mercado interno, processamento industrial e a exportação de frutos in natura. Embora o mercado interno seja o principal destino da produção, merece destaque o aumento das exportações brasileiras da fruta que setuplicaram no período 2000-2006 alcançando US$ 32 milhões (SILVA; ALMEIDA; FERRAZ, 2008). No mercado interno, os preços praticados acompanham a disponibilidade da fruta, atingindo valores máximos nos meses de entressafra, quando a oferta é restrita. No período de safra, quando a oferta da fruta é maior, o produtor tem como alternativa a exportação de frutos, cujos preços são superiores aos praticados pelo mercado interno. De forma geral, o processamento industrial é o destino dos frutos que não atendem as exigências do mercado interno e externo.pdf 159
The XMM-LSS Survey: A well controlled X-ray cluster sample over the D1 CFHTLS area
We present the XMM-LSS cluster catalogue corresponding to the CFHTLS D1 area.
The list contains 13 spectroscopically confirmed, X-ray selected galaxy
clusters over 0.8 deg2 to a redshift of unity and so constitutes the highest
density sample of clusters to date. Cluster X-ray bolometric luminosities range
from 0.03 to 5x10^{44} erg/s. In this study, we describe our catalogue
construction procedure: from the detection of X-ray cluster candidates to the
compilation of a spectroscopically confirmed cluster sample with an explicit
selection function. The procedure further provides basic X-ray products such as
cluster temperature, flux and luminosity. We detected slightly more clusters
with a (0.5-2.0 keV) X-ray fluxes of >2x10^{-14} erg/s/cm^{-2} than we expected
based on expectations from deep ROSAT surveys. We also present the
Luminosity-Temperature relation for our 9 brightest objects possessing a
reliable temperature determination. The slope is in good agreement with the
local relation, yet compatible with a luminosity enhancement for the 0.15 < z<
0.35 objects having 1 < T < 2 keV, a population that the XMM-LSS is identifying
systematically for the first time. The present study permits the compilation of
cluster samples from XMM images whose selection biases are understood. This
allows, in addition to studies of large-scale structure, the systematic
investigation of cluster scaling law evolution, especially for low mass X-ray
groups which constitute the bulk of our observed cluster population. All
cluster ancillary data (images, profiles, spectra) are made available in
electronic form via the XMM-LSS cluster database.Comment: 12 pages 5 figures, MNRAS accepted. The paper with full resolution
cluster images is available at
http://vela.astro.ulg.ac.be/themes/spatial/xmm/LSS/rel_pub_e.htm
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