13,061 research outputs found
Two planetary systems with transiting Earth-size and super-Earth planets orbiting late-type dwarf stars
We present two new planetary systems found around cool dwarf stars with data
from the K2 mission. The first system was found in K2-239 (EPIC 248545986),
char- acterized in this work as M3.0V and observed in the 14th campaign of K2.
It consists of three Earth-size transiting planets with radii of 1.1, 1.0 and
1.1 R Earth, showing a compact configuration with orbital periods of 5.24, 7.78
and 10.1 days, close to 2:3:4 resonance. The second was found in K2-240 (EPIC
249801827), characterized in this work as M0.5V and observed in the 15th
campaign. It consists of two transiting super-Earths with radii 2.0 and 1.8 R
Earth and orbital periods of 6.03 and 20.5 days. The equilibrium temperatures
of the atmospheres of these planets are estimated to be in the range of 380-600
K and the amplitudes of signals in transmission spectroscopy are estimated at
~10 ppm.Comment: Accepted for publication in MNRAS letter
Temporal changes of the flare activity of Proxima Cen
We study temporal variations of the emission lines of Halpha, Hepsilon, H and
K Ca II, D1 and D2 Na I, 4026 and 5876 A He I in the HARPS spectra of Proxima
Centauri across an extended time of 13.2 years, from May 27, 2004, to September
30, 2017.
Aims. We analyse the common behaviour and differences in the intensities and
profiles of different emission lines in flare and quiet modes of Proxima
activity.
Methods. We compare the pseudo-equivalent widths (pEW) and profiles of the
emission lines in the HARPS high-resolution (R ~ 115,000) spectra observed at
the same epochs.
Results. All emission lines show variability with a timescale of at least 10
min. The strength of all lines except He I 4026 A correlate with \Halpha.
During strong flares the `red asymmetry' appears in the Halpha emission line
indicating the infall of hot condensed matter into the chromosphere with
velocities greater than 100 km/s disturbing chromospheric layers. As a result,
the strength of the Ca II lines anti-correlates with Halpha during strong
flares. The He I lines at 4026 and 5876 A appear in the strong flares. The
cores of D1 and D2 Na I lines are also seen in emission. During the minimum
activity of Proxima Centauri, Ca II lines and Hepsilon almost disappear while
the blue part of the Na I emission lines is affected by the absorption in the
extending and condensing flows.
Conclusions. We see different behaviour of emission lines formed in the flare
regions and chromosphere. Chromosphere layers of Proxima Cen are likely heated
by the flare events; these layers are cooled in the `non-flare' mode. The
self-absorption structures in cores of our emission lines vary with time due to
the presence of a complicated system of inward and outward matter flows in the
absorbing layers.Comment: 22 pages, 12 Figures, accepted by A
Real-time digital signal processor implementation of self-calibrating pulse-shape discriminator for high purity germanium
Pulse-shape analysis of the ionization signals from germanium gamma-ray
spectrometers is a method for obtaining information that can characterize an
event beyond just the total energy deposited in the crystal. However, as
typically employed, this method is data-intensive requiring the digitization,
transfer, and recording of electronic signals from the spectrometer. A hardware
realization of a real-time digital signal processor for implementing a
parametric pulse shape is presented. Specifically, a previously developed
method for distinguishing between single-site and multi-site gamma-ray
interactions is demonstrated in an on-line digital signal processor, compared
with the original off-line pulse-shape analysis routine, and shown to have no
significant difference. Reduction of the amount of the recorded information per
event is shown to translate into higher duty-cycle data acquisition rates while
retaining the benefits of additional event characterization from pulse-shape
analysis.Comment: Accepted by NIM
Barred-beach morphological control on infragravity motion
A conceptual analysis of the coupling between bars and infragravity waves is performed combining laboratory experiments and numerical modeling. Experiments are carried out in a wave flume with a barred profile. The Boussinesq fully-nonlinear model SERR1D is validated with the laboratory data and a sensitivity analysis is performed next to study the influence on the infragravity wave dynamics of bar amplitude and location, and swash zone slope. A novel technique of incident and reflected motions separation that conserves temporal characteristics is applied. We observe that changing bar characteristics induces substantial variations in trapped energy. Interestingly, a modification of swash zone slope has a large influence on the reflected component, controlling amplitude and phase time-lag, and consequently on the resonant pattern. Variations of trapped infragravity energy induced by changes of swash zone slope reach 25 %. These changes in infragravity pattern consequently affect short-wave dynamics by modifying the breakpoint location and the breaking intensity. Our conceptual investigation suggests the existence of a morphological feedback through the action of evolving morphology on infragravity structures which modulates the action of short-waves on the morphology itself
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Search for physics beyond the standard model in events with Ï„ leptons, jets, and large transverse momentum imbalance in pp collisions at [Formula: see text].
A search for physics beyond the standard model is performed with events having one or more hadronically decaying Ï„ leptons, highly energetic jets, and large transverse momentum imbalance. The data sample corresponds to an integrated luminosity of 4.98 fb-1 of proton-proton collisions at [Formula: see text] collected with the CMS detector at the LHC in 2011. The number of observed events is consistent with predictions for standard model processes. Lower limits on the mass of the gluino in supersymmetric models are determined
Association of Systemic Lupus Erythematosus Clinical Features with European Population Genetic Substructure
Systemic Lupus Erythematosus (SLE) is an autoimmune disease with a very varied spectrum of clinical manifestations that could be partly determined by genetic factors. We aimed to determine the relationship between prevalence of 11 clinical features and age of disease onset with European population genetic substructure. Data from 1413 patients of European ancestry recruited in nine countries was tested for association with genotypes of top ancestry informative markers. This analysis was done with logistic regression between phenotypes and genotypes or principal components extracted from them. We used a genetic additive model and adjusted for gender and disease duration. Three clinical features showed association with ancestry informative markers: autoantibody production defined as immunologic disorder (P = 6.8×10(-4)), oral ulcers (P = 6.9×10(-4)) and photosensitivity (P = 0.002). Immunologic disorder was associated with genotypes more common in Southern European ancestries, whereas the opposite trend was observed for photosensitivity. Oral ulcers were specifically more common in patients of Spanish and Portuguese self-reported ancestry. These results should be taken into account in future research and suggest new hypotheses and possible underlying mechanisms to be investigated. A first hypothesis linking photosensitivity with variation in skin pigmentation is suggested
IFE Plant Technology Overview and contribution to HiPER proposal
HiPER is the European Project for Laser Fusion that has been able to join 26 institutions and signed under formal government agreement by 6 countries inside the ESFRI Program of the European Union (EU). The project is already extended by EU for two years more (until 2013) after its first preparatory phase from 2008. A large work has been developed in different areas to arrive to a design of repetitive operation of Laser Fusion Reactor, and decisions are envisioned in the next phase of Technology Development or Risk Reduction for Engineering or Power Plant facilities (or both). Chamber design has been very much completed for Engineering phase and starting of preliminary options for Reactor Power Plant have been established and review here
Depositional Depth of Laminated Carbonate Deposits: Insights From the Lower Cretaceous Valdeprado Formation (Cameros Basin, Northern Spain)
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Measurement of masses in the [Formula: see text] system by kinematic endpoints in pp collisions at [Formula: see text].
A simultaneous measurement of the top-quark, W-boson, and neutrino masses is reported for [Formula: see text] events selected in the dilepton final state from a data sample corresponding to an integrated luminosity of 5.0 fb-1 collected by the CMS experiment in pp collisions at [Formula: see text]. The analysis is based on endpoint determinations in kinematic distributions. When the neutrino and W-boson masses are constrained to their world-average values, a top-quark mass value of [Formula: see text] is obtained. When such constraints are not used, the three particle masses are obtained in a simultaneous fit. In this unconstrained mode the study serves as a test of mass determination methods that may be used in beyond standard model physics scenarios where several masses in a decay chain may be unknown and undetected particles lead to underconstrained kinematics
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