11,860 research outputs found
Photometric redshifts and selection of high redshift galaxies in the NTT and Hubble Deep Fields
We present and compare in this paper new photometric redshift catalogs of the
galaxies in three public fields: the NTT Deep Field, the HDF-N and the HDF-S.
Photometric redshifts have been obtained for thewhole sample, by adopting a
minimization technique on a spectral library drawn from the Bruzual
and Charlot synthesis models, with the addition of dust and intergalactic
absorption. The accuracy, determined from 125 galaxies with known spectroscopic
redshifts, is in the redshift intervals . The global redshift distribution of I-selected galaxies shows a
distinct peak at intermediate redshifts, z~0.6 at I_{AB}<26 and z~0.8 at
I_{AB}<27.5 followed by a tail extending to z~6. We also present for the first
time the redshift distribution of the total IR-selected sample to faint limits
( and ). It is found that the number density of galaxies
at 1.25<z<1.5 is ~ 0.1 /arcmin^22 at J<=21 and ~1./arcmin^2} at J<22, and drops
to 0.3/arcmin^2 (at J<22) at 1.5<z<2. The HDFs data sets are used to compare
the different results from color selection criteria and photometric redshifts
in detecting galaxies in the redshift range 3.5<z<4.5 Photometric redshifts
predict a number of high z candidates in both the HDF-N and HDF-S that is
nearly 2 times larger than color selection criteria, and it is shown that this
is primarily due to the inclusion of dusty models that were discarded in the
original color selection criteria by Madau et al 1998. In several cases, the
selection of these objects is made possible by the constraints from the IR
bands. Finally, it is shown that galactic M stars may mimic z>5 candidates in
the HDF filter set and that the 4 brightest candidates at in the HDF-S
are indeed most likely M stars. (ABRIDGED)Comment: Version accepted on July, 20, 2000. To appear on Astronomical
Journal, Nov 2000. The data and photometric redshift catalogs presented here
are available on line at http://www.mporzio.astro.it/HIGH
¿Modifican el PSA los licopenos de la dieta y exógenos?
El objetivo del presente artÃculo es describir la historia alimentaria y la composición corporal de pacientes con alto
riesgo de padecer cáncer de próstata (CAP) y observar la influencia de la
suplementación con licopeno sobre el PSA de la misma población.Fil: López Laur, José Daniel.
Universidad Nacional de Cuyo. Facultad de Ciencias MédicasFil: López Fontana, C..
Universidad Nacional de Cuyo. Facultad de Ciencias MédicasFil: López Fontana, G..
Universidad Nacional de Cuyo. Facultad de Ciencias MédicasFil: López Fontana, R..
Universidad Nacional de Cuyo. Facultad de Ciencias Médica
Stress corrosion cracking of titanium alloys
The effect of hydrogen on the properties of metals, including titanium and its alloys, was investigated. The basic theories of stress corrosion of titanium alloys are reviewed along with the literature concerned with the effect of absorbed hydrogen on the mechanical properties of metals. Finally, the basic modes of metal fracture and their importance to this study is considered. The experimental work was designed to determine the effects of hydrogen concentration on the critical strain at which plastic instability along pure shear directions occurs. The materials used were titanium alloys Ti-8Al-lMo-lV and Ti-5Al-2.5Sn
Phonon Properties of Knbo3 and Ktao3 from First-Principles Calculations
The frequencies of transverse-optical phonons in KNbO and
KTaO are calculated in the frozen-phonon scheme making use of the
full-potential linearized muffin-tin orbital method. The calculated frequencies
in the cubic phase of KNbO and in the tetragonal ferroelectric phase are in
good agreement with experimental data. For KTaO, the effect of lattice
volume was found to be substantial on the frequency of the soft mode, but
rather small on the relative displacement patterns of atoms in all three modes
of the symmetry. The TO frequencies in KTaO are found to be of the
order of, but somehow higher than, the corresponding frequencies in cubic
KNbO.Comment: 8 pages + 1 LaTeX figure, Revtex 3.0, SISSA-CM-94-00
Detection of high impact tourist events from occupancy data. An application to Piemonte, Italy
La Matematica e le sue Applicazioni - Politecnico DIMAT n.06/201
Detection of high impact tourist events from occupancy data. An application to Piemonte, Italy.
La Matematica e le sue Applicazioni - Politecnico DIMAT n.06/201
The Role of Commercial Banks and Financial Intermediaries in the New Consensus Macroeconomics (NCM): A Preliminary and Critical Appraisal of Old and New Models
Giuseppe Fontana and Marco Veronese Passarella in this chapter, entitled, ‘Aggregate Demand, Money and Finance in the New Consensus Macroeconomics: a Critical Appraisal’, critically assess the ‘New Consensus Macroeconomics’ (NCM) theory and its recent developments. Building on the Wicksellian ‘two-interest rates model’, the NCM highlights the role of interest rates in the transmission mechanism of monetary policy, whereas monetary aggregates are treated as residual variables. However, in contrast with Wicksell’s theory, banks and financial institutions are usually neglected in the NCM theory. As a result, the financial instability and recurrent banking crises of modern economies have received little attention in modern macroeconomics. This chapter has three main goals. First, it aims to provide a critical analysis of the original NCM model and some recent developments. Second, it aims to show that few amendments to it are sufficient to account for the financial instability and banking crises of real-world economies. Third, it shows that some important policy-making conclusions logically follow once the role of banks, credit and finance is properly taken on board
- …