6,698 research outputs found

    New skeletal tuberculosis cases in past populations from Western Hungary (Transdanubia)

    Get PDF
    The distribution, antiquity and epidemiology of tuberculosis (TB) have previously been studied in osteoarchaeological material in the eastern part of Hungary, mainly on the Great Plain. The purpose of this study is to map the occurrence of skeletal TB in different centuries in the western part of Hungary, Transdanubia, and to present new cases we have found. Palaeopathological analysis was carried out using macroscopic observation supported by radiographic and molecular methods. A large human osteoarchaeological sample (n = 5684) from Transdanubian archaeological sites ranging from the 2nd to the 18th centuries served as a source of material. Spinal TB was observed in seven individuals (in three specimens with Pott's disease two of which also had cold abscess) and hip TB was assumed in one case. The results of DNA for Mycobacterium tuberculosis were positive in seven of the eight cases identified by paleopathology, and negative in the assumed case of hip TB. However, the molecular results are consistent with highly fragmented DNA, which limited further analysis. Based on the present study and previously published cases, osteotuberculosis was found in Transdanubia mainly during the 9th–13th centuries. However, there are no signs of TB in many other 9th–13th century sites, even in those that lie geographically close to those where osteotuberculous cases were found. This may be due to a true absence of TB caused by the different living conditions, way of life, or origin of these populations. An alternative explanation is that TB was present in some individuals with no typical paleopathology, but that death occurred before skeletal morphological features could develop

    CoRoT-TESS eclipsing binaries with light-travel-time effect

    Get PDF
    Identifying long-period eclipsing binaries with space-based photometry is still a challenge even in the century of space telescopes due to the relatively short observation sequences and short lifetime of these missions. The Transiting Exoplanet Survey Satellite (TESS) space telescope is an appropriate tool to supplement previous space-based observations. In this paper we report the first results of the eclipse timing variation (ETV) analyses of eclipsing binaries (EBs) measured by CoRoT and TESS space telescopes. Among the 1428 EB candidates we found 4 new potential triple candidates, for which ETV was analysed and fitted by the well-known light-travel-time effect (LTTE). One of them shows significant phase shift in its folded light curve which required extra care. In this paper we also present some other systems showing significant ETV signals that could be explained by mass transfer or apsidal motion.Comment: 6 pages, 5 figures, accepted for publication in MNRAS. Table 3 is available as online supplementary materia

    Eclipse timing variation analysis of OGLE-IV eclipsing binaries towards the Galactic Bulge – I. Hierarchical triple system candidates

    Get PDF
    We report a study of the eclipse timing variation (ETV) of short period (P16dP_1\le 6^d) eclipsing binaries (EB) monitored during the photometric survey OGLE-IV. From the 425\,193 EBs we selected approximately 80\,000 binaries that we found suitable for further examination. Among them we identified 992 potential hierarchical triple (or multiple ) system candidates exhibiting light-travel-time effect (LTTE). Besides, we obtained the orbital parameters of these systems and carried out statistical analyses on the properties of these candidates. We found that (i) there is a significant lack of triple systems where the outer period is less than 500 days; (ii) the distribution of the outer eccentricities has a maximum around e20.3e_2\approx0.3; (iii) the outer mass ratio calculated from an estimated minimum mass of the third component is lower than q20.5q_2\sim 0.5 for the majority of the sample. We also present some systems that deserve special attention. (i) There are four candidates that show double periodic ETV, which we explain by the presence of a fourth companion. (ii) For two systems the perturbations of the third component are also found to be significant therefore we give a combined dynamical and LTTE ETV solution. (iii) For one system the third component is found to be probably in the substellar mass domain.Comment: Accepted for publication in MNRA

    TICs 167692429 and 220397947: the first compact hierarchical triple stars discovered with TESS

    Get PDF
    We report the discovery and complex analyses of the first two compact hierarchical triple star systems discovered with TESS in or near its southern continuous viewing zone during Year 1. Both TICs 167692429 and 220397947 were previously unknown eclipsing binaries, and the presence of a third companion star was inferred from eclipse timing variations exhibiting signatures of strong third-body perturbations and, in the first system, also from eclipse depth variations. We carried out comprehensive analyses, including the simultaneous photodynamical modelling of TESS and archival ground-based WASP light curves, as well as eclipse timing variation curves. Also, for the first time, we included in the simultaneous fits multiple star spectral energy distribution data and theoretical PARSEC stellar isochrones, taking into account Gaia DR2 parallaxes and catalogued metallicities. We find that both systems have twin F-star binaries and a lower mass tertiary star. In the TIC 167692429 system, the inner binary is moderately inclined (imut = 27°) with respect to the outer orbit, and the binary versus outer (triple) orbital periods are 10.3 versus 331 d, respectively. The mutually inclined orbits cause a driven precession of the binary orbital plane that leads to the disappearance of binary eclipses for long intervals. In the case of TIC 220397947, the two orbital planes are more nearly aligned and the inner versus outer orbital periods are 3.5 and 77 d, respectively. In the absence of radial velocity observations, we were unable to calculate highly accurate masses and ages for the two systems. According to stellar isochrones TIC 167692429 might be either a pre-main sequence (MS) or an older post-MS system. In the case of TIC 220397947, our solution prefers a young pre-MS scenario

    Overtone and multi-mode RR Lyrae stars in the globular cluster M3

    Get PDF
    The overtone and multi-mode RR Lyrae stars in the globular cluster M3 are studied using a 200-d long, B,VB,V and ICI_{\mathrm C} time-series photometry obtained in 2012. 70\% of the 52 overtone variables observed show some kind of multi-periodicity (additional frequency at f0.61=f1O/0.61{f_{0.61}}={f_{\mathrm {1O}}}/0.61 frequency ratio, Blazhko effect, double/multi-mode pulsation, period doubling). A signal at 0.587 frequency ratio to the fundamental-mode frequency is detected in the double-mode star, V13, which may be identified as the second radial overtone mode. If this mode-identification is correct, than V13 is the first RR Lyrae star showing triple-mode pulsation of the first three radial modes. Either the Blazhko effect or the f0.61{f_{0.61}} frequency (or both of these phenomena) appear in 7 double-mode stars. The P1O/PFP_{\mathrm{1O}}/P_{\mathrm{F}} period ratio of RRd stars showing the Blazhko effect are anomalous. A displacement of the main frequency component at the fundamental-mode with the value of modulation frequency (or its half) is detected in three Blazhko RRd stars parallel with the appearance of the overtone-mode pulsation. The f0.61{f_{0.61}} frequency appears in RRc stars that lie at the blue side of the double-mode region and in RRd stars, raising the suspicion that its occurrence may be connected to double-mode pulsation. The changes of the Blazhko and double-mode properties of the stars are also reviewed using the recent and archive photometric data.Comment: accepted for publication in ApJ Suppl. 26 pages, 25 figure

    The compact multiple system HIP 41431

    Get PDF
    The nearby (50 pc) K7V dwarf HIP 41431 (EPIC 212096658) is a compact three-tier hierarchy. Three K7V stars with similar masses, from 0.61 to 0.63 solar, make a triple-lined spectroscopic system where the inner binary with a period of 2.9 d is eclipsing, and the outer companion on a 59-d orbit exerts strong dynamical influence revealed by the eclipse time variation in the Kepler photometry. Moreover, the centre of mass of the triple system moves on a 3.9-yr orbit, modulating the proper motion. The mass of the fourth star is 0.35 solar. The Kepler and ground-based photometry and radial velocities from four different spectrographs are used to adjust the spectro-photodynamical model that accounts for dynamical interaction. The mutual inclination between the two inner orbits is 2{^{circ}.}16 ± 0{^{circ}.}11, while the outer orbit is inclined to their common plane by 21°±16°. The inner orbit precesses under the influence of both outer orbits, causing observable variation of the eclipse depth. Moreover, the phase of the inner binary is strongly modulated with a 59-d period and its line of apsides precesses. The middle orbit with eccentricity e = 0.28 also precesses, causing the observed variation of its radial velocity curve. Masses and other parameters of stars in this unique hierarchy are determined. This system is dynamically stable and likely old

    Electron spin-orbit splitting in InGaAs/InP quantum well studied by means of the weak antilocalization and spin-zero effects in tilted magnetic fields

    Full text link
    The coupling between Zeeman spin splitting and Rashba spin-orbit terms has been studied experimentally in a gated InGaAs/InP quantum well structure by means of simultaneous measurements of the weak antilocalization (WAL) effect and beating in the SdH oscillations. The strength of the Zeeman splitting was regulated by tilting the magnetic field with the spin-zeros in the SdH oscillations, which are not always present, being enhanced by the tilt. In tilted fields the spin-orbit and Zeeman splittings are not additive, and a simple expression is given for the energy levels. The Rashba parameter and the electron g-factor were extracted from the position of the spin zeros in tilted fields. A good agreement is obtained for the spin-orbit coupling strength from the spin-zeros and weak antilocalization measurements.Comment: Accepted for publication in Semiconductors Science and Technolog
    corecore