8,195 research outputs found
Semi-Empirical Cepheid Period-Luminosity Relations in Sloan Magnitudes
In this paper we derive semi-empirical Cepheid period-luminosity (P-L)
relations in the Sloan ugriz magnitudes by combining the observed BVI mean
magnitudes from the Large Magellanic Cloud Cepheids (LMC) and theoretical
bolometric corrections. We also constructed empirical gr band P-L relations,
using the publicly available Johnson-Sloan photometric transformations, to be
compared with our semi-empirical P-L relations. These two sets of P-L relations
are consistent with each other.Comment: 4 pages, 2 tables and 2 figures, ApJ accepte
Center Vortex Model for the Infrared Sector of SU(3) Yang-Mills Theory - Vortex Free Energy
The vortex free energy is studied in the random vortex world-surface model of
the infrared sector of SU(3) Yang-Mills theory. The free energy of a center
vortex extending into two spatial directions, which is introduced into
Yang-Mills configurations when acting with the 't Hooft loop operator, is
verified to furnish an order parameter for the deconfinement phase transition.
It is shown to exhibit a weak discontinuity at the critical temperature,
corresponding to the weak first order character of the transition.Comment: 13 pages, 2 figures containing 3 eps file
Near infrared and optical emission of WASP-5 b
CONTEXT: Thermal emission from extrasolar planets makes it possible to study
important physical processes in their atmospheres and derive more precise
orbital elements. AIMS: By using new near infrared and optical data, we examine
how these data constrain the orbital eccentricity and the thermal properties of
the planet atmosphere. METHODS: The full light curves acquired by the TESS
satellite from two sectors are used to put upper limit on the amplitude of the
planet's phase variation and estimate the occultation depth. Two, already
published and one, yet unpublished followup observations in the 2MASS K (Ks)
band are employed to derive a more precise occultation light curve in this near
infrared waveband. RESULTS: The merged occultation light curve in the Ks band
comprises 4515 data points. The data confirm the results of the earlier
eccentricity estimates, suggesting circular orbit: e=0.005+/-0.015. The high
value of the flux depression of (2.70+/-0.14) ppt in the Ks band excludes
simple black body emission at the 10 sigma level and disagrees also with
current atmospheric models at the (4-7) sigma level. From the analysis of the
TESS data, in the visual band we found tentative evidence for a near noise
level detection of the secondary eclipse, and placed constraints on the
associated amplitude of the planet's phase variation. A formal box fit yields
an occultation depth of (0.157+/-0.056) ppt. This implies a relatively high
geometric albedo of Ag=0.43+/-0.15 for fully efficient atmospheric circulation
and Ag=0.29+/-0.15 for no circulation at all. No preference can be seen either
for the oxygen-enhanced, or for the carbon-enhanced atmosphere models.Comment: After the 2nd referee report. Wrong citation of e*cos(w) by Baskin et
al. (2013) has been corrected. Appendix B is supplied by another figur
Instantons and Supersymmetry
The role of instantons in describing non-perturbative aspects of globally supersymmetric gauge theories is reviewed. The cases of theories with N=1, N=2 and N=4 supersymmetry are discussed. Special attention is devoted to the intriguing relation between instanton solutions in field theory and branes in string theory
Pulmonary and cardiac drugs: clinically relevant interactions
Chronic heart and lung diseases are very common in the elderly population. The combination of chronic heart failure and chronic obstructive pulmonary disease (COPD) is also common and, according to current guidelines, these patients should be treated for both diseases. In patients with heart failure, beta-blockers are very important drugs because their use is associated with significantly improved morbidity and mortality. These beneficial effects were documented in patients with and without COPD, although theoretically there is a risk for bronchoconstriction, particularly with non-beta1 selective blockers. In COPD patients, long-acting sympathomimetics (LABA) improve lung function, dyspnea, and quality of life and their combination with a beta-blocker makes sense from a pharmacological and a clinical point of view, because any potential arrhythmogenic effects of the LABA will be ameliorated by the beta-blocker. Inhaled tiotropium, a long-acting muscarinic antagonist (LAMA), has been extensively investigated and no safety concerns were reported in terms of cardiac adverse effects. The same applies for the other approved LAMA preparations and LAMA-LABA combinations. Severe COPD causes air-trapping with increasing pressures in the thorax, leading to limitations in blood return into the thorax from the periphery of the body. This causes a decrease in stroke volume and cardiac index and is associated with dyspnea. All these adverse effects can be ameliorated by potent anti-obstructive therapy as recently shown by means of a LABA-LAMA combination
Comparison of bread wheat varieties with different breeding origin under organic and low input management
The aims of the study were to compare 37 bread wheat varieties with different breeding origin under conventional and organic farming conditions in Hungary and Austria for three years and to identify traits highly sensitive to management systems that could be separated according to their suggested selecting environments. According to the results, heading date, sensitivity to leaf rust and powdery mildew had high heritability, thus, for economic reasons, it is reasonable to select for these traits in conventional fields even if the selection target is organic agriculture. On the contrary, selection for grain yield, test weight, leaf-inclination and vigorous growth should be done later in the target environment. It was concluded that the selecting environment has measurable effects on the performance of bread wheat varieties. Our results could help organic breeders in their selection work, especially in the continental climatic zone of Europe
Vibrational relaxation measurements in CO2 USING an induced fluorescence technique
Vibrational relaxation measurements in carbon dioxide using induced infrared fluorescence techniqu
A multi-color and Fourier study of RR Lyrae variables in the globular cluster NGC 5272 (M3)
We have performed a detailed study of the pulsational and evolutionary
characteristics of 133 RR Lyrae stars in the globular cluster NGC5272 (M3)
using highly accurate BVI data taken on 5 separate epochs. M3 seems to contain
no less than ~32% of Blazhko stars, and the occurrence and characteristics of
the Blazhko effect have been analyzed in detail. We have identified a good
number (~ 14%) of overluminous RR Lyrae stars that are likely in a more
advanced evolutionary stage off the Zero Age Horizontal Branch (ZAHB). Physical
parameters (i.e. temperature, luminosity, mass) have been derived from (B--V)
colors and accurate color-temperature calibration, and compared with Horizontal
Branch evolutionary models and with the requirements of stellar pulsation
theory. Additional analysis by means of Fourier decomposition of the V light
curves confirms, as expected, that no metallicity spread is present in M3.
Evolution off the ZAHB does not affect [Fe/H] determinations, whereas Blazhko
stars at low amplitude phase do affect [Fe/H] distributions as they appear more
metal-rich. Absolute magnitudes derived from Fourier coefficients might provide
useful average estimates for groups of stars, if applicable, but do not give
reliable {\em individual} values. Intrinsic colors derived from Fourier
coefficients show significant discrepancies with the observed ones, hence the
resulting temperatures and temperature-related parameters are unreliable.Comment: 86 pages, 19 figures, 13 tables, in press A
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