123 research outputs found

    Gravity darkening and tidally perturbed stellar pulsation in the misaligned exoplanet system WASP-33

    Get PDF
    WASP-33 is one of the few ÎŽ\delta Sct stars with a known planetary companion. By analyzing the stellar oscillations, we search for possible star-planet interactions in the pattern of the pulsation. We made use of the Transit and Light Curve Modeller (TLCM) to solve the light curve from the Transiting Exoplanet Survey Satellite (TESS). We include gravity darkening into our analysis. The stellar oscillation pattern of WASP-33 clearly shows signs of several tidally perturbed modes. We find that there are peaks in the frequency spectrum that are at or near the 33rd, 1212th and 2525th orbital harmonics (forb∌0.82f_{orb} \sim 0.82 d−1^{-1}). Also, there is a prominent overabundance of pulsational frequencies rightwards of the orbital harmonics, being characteristic of a tidally perturbed stellar pulsation, which is an outcome of star-planet interactions in the misaligned system. There are peaks in both the ÎŽ\delta Sct and Îł\gamma Dor ranges of the Fourier spectrum, implying that WASP-33 is a Îł\gamma Dor -- ÎŽ\delta Sct hybrid pulsator. The transit light curves are best fitted by a gravity darkened stellar model, and the planet parameters are consistent with earlier determinations.Comment: Accepted in A&A on 12 March 2022, 6 pages, 4 figure

    Controllability and controller-observer design for a class of linear time-varying systems

    Get PDF
    “The final publication is available at Springer via http://dx.doi.org/10.1007/s10852-012-9212-6"In this paper a class of linear time-varying control systems is considered. The time variation consists of a scalar time-varying coefficient multiplying the state matrix of an otherwise time-invariant system. Under very weak assumptions of this coefficient, we show that the controllability can be assessed by an algebraic rank condition, Kalman canonical decomposition is possible, and we give a method for designing a linear state-feedback controller and Luenberger observer

    Multivariate searches for single top quark production with the D0 detector

    Get PDF
    We present a search for electroweak production of single top quarks in the s-channel (p-pbar -> t bbar + X) and t-channel (p-pbar -> tq bbar + X) modes. We have analyzed 230 pb^(-1) of data collected with the D0 detector at the Fermilab Tevatron collider at a center-of-mass energy of sqrt(s) = 1.96 TeV. Two separate analysis methods are used: neural networks and a cut-based analysis. No evidence for a single top quark signal is found. We set 95% confidence level upper limits on the production cross sections using Bayesian statistics, based on event counts and binned likelihoods formed from the neural network output. The limits from the neural network (cut-based) analysis are 6.4 pb (10.6 pb) in the s-channel and 5.0 pb (11.3 pb) in the t-channel.Comment: submitted to Phys. Rev. D, Fermilab preprint Fermilab-Pub-06/069-

    2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.

    Get PDF
    S

    2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.

    Get PDF
    S

    Measurement of the ttbar production cross section in pbarp collisions at sqrt(s) = 1.96 TeV using secondary vertex b tagging

    Get PDF
    We report a new measurement of the ttbar production cross section in pbarp collisions at a center-of-mass energy of 1.96 TeV using events with one charged lepton (electron or muon), missing transverse energy, and jets. Using 425 pb^{-1} of data collected using the D0 detector at the Fermilab Tevatron Collider, and enhancing the ttbar content of the sample by tagging b jets with a secondary vertex tagging algorithm, the ttbar production cross section is measured to be: 6.6 \pm 0.9 (stat+syst) \pm 0.4 (lum) pb. This cross section is the most precise D0 measurement to date for ttbar production and is in good agreement with standard model expectations.Comment: 25 pages, 13 figure

    withdrawn 2017 hrs ehra ecas aphrs solaece expert consensus statement on catheter and surgical ablation of atrial fibrillation

    Get PDF
    n/
    • 

    corecore