114 research outputs found

    New views on hyperplastic endometrial lesions classification – endometrial intraepithelial neoplasia (EIN)

    Get PDF
    Abstract The aim of the study was to present a new EIN classification of premalignant endometrial lesions. The diagnosis of precancerous disease of the endometrium remains non-standardized because the most widely used World Health Organisation classification is a poorly reproducible system, which does not specify objective architectural criteria for each category of hyperplasia and does not correspond to an appropriate clinical management (undertreatment, overtreatment of the lesions). The new proposed EIN diagnostic schema, based on integrated morphological, genetic molecular, objective histomorphometric (D-score) and clinical outcome studies, divides endometrial lesions into three categories: benign hyperplasia, endometrial intraepithelial neoplasia, and cancer

    Microlensing optical depth and event rate in the OGLE-IV Galactic plane fields

    Get PDF
    Searches for gravitational microlensing events are traditionally concentrated on the central regions of the Galactic bulge but many microlensing events are expected to occur in the Galactic plane, far from the Galactic Center. Owing to the difficulty in conducting high-cadence observations of the Galactic plane over its vast area, which are necessary for the detection of microlensing events, their global properties were hitherto unknown. Here, we present results of the first comprehensive search for microlensing events in the Galactic plane. We searched an area of almost 3000 square degrees along the Galactic plane (|b|<7, 0<l<50, 190<l<360 deg) observed by the Optical Gravitational Lensing Experiment (OGLE) during 2013-2019 and detected 630 events. We demonstrate that the mean Einstein timescales of Galactic plane microlensing events are on average three times longer than those of Galactic bulge events, with little dependence on the Galactic longitude. We also measure the microlensing optical depth and event rate as a function of Galactic longitude and demonstrate that they exponentially decrease with the angular distance from the Galactic Center (with the characteristic angular scale length of 32 deg). The average optical depth decreases from 0.5×1060.5\times 10^{-6} at l=10 deg to 1.5×1081.5\times 10^{-8} in the Galactic anticenter. We also find that the optical depth in the longitude range 240<l<330 deg is asymmetric about the Galactic equator, which we interpret as a signature of the Galactic warp.Comment: ApJS, in pres

    Microlensing optical depth and event rate in the OGLE-IV Galactic plane fields

    Get PDF
    Searches for gravitational microlensing events are traditionally concentrated on the central regions of the Galactic bulge but many microlensing events are expected to occur in the Galactic plane, far from the Galactic Center. Owing to the difficulty in conducting high-cadence observations of the Galactic plane over its vast area, which are necessary for the detection of microlensing events, their global properties were hitherto unknown. Here, we present results of the first comprehensive search for microlensing events in the Galactic plane. We searched an area of almost 3000 square degrees along the Galactic plane (|b| < 7°, 0° < l < 50°, 190° < l < 360°) observed by the Optical Gravitational Lensing Experiment (OGLE) during 2013–2019 and detected 630 events. We demonstrate that the mean Einstein timescales of Galactic plane microlensing events are on average three times longer than those of Galactic bulge events, with little dependence on the Galactic longitude. We also measure the microlensing optical depth and event rate as a function of Galactic longitude and demonstrate that they exponentially decrease with the angular distance from the Galactic Center (with the characteristic angular scale length of 32°). The average optical depth decreases from 0.5 × 10⁻⁶ at l = 10° to 1.5 × 10⁻⁸ in the Galactic anticenter. We also find that the optical depth in the longitude range 240° < l < 330° is asymmetric about the Galactic equator, which we interpret as a signature of the Galactic warp

    OGLE-ing the Magellanic System: RR Lyrae Stars in the Bridge

    Get PDF
    We use the extended and updated Optical Gravitational Lensing Experiment (OGLE) Collection of Variable Stars to thoroughly analyze the distribution of RR Lyrae stars in the Magellanic Bridge. We use photometric metallicities to derive the absolute Wesenheit magnitude and individual distance of each RR Lyrae star. We confirm results from our earlier study showing that RR Lyrae stars are present in between the Magellanic Clouds, though their three-dimensional distribution more resembles two extended overlapping structures than a strict bridge-like connection. The contours do connect in the southern parts of the Bridge, albeit on a level too low to state that an evident connection exists. To test the sample numerically, we use multi-Gaussian fitting and conclude that there is no additional population or overdensity located in the Bridge. We also try to reproduce results on the putative RR Lyrae Magellanic Bridge stream by selecting RR Lyrae candidates from Gaia Data Release 1. We show that we are not able to obtain the evident connection of the Clouds without many spurious sources in the sample, as the cuts are not able to remove artifacts without eliminating the evident connection at the same time. Moreover, for the first time, we present the Gaia Data Release 2 RR Lyrae stars in the Magellanic Bridge area and show that their distribution matches our results

    OGLE-ing the Magellanic System: RR Lyrae Stars in the Bridge

    Get PDF
    We use the extended and updated Optical Gravitational Lensing Experiment (OGLE) Collection of Variable Stars to thoroughly analyze the distribution of RR Lyrae stars in the Magellanic Bridge. We use photometric metallicities to derive the absolute Wesenheit magnitude and individual distance of each RR Lyrae star. We confirm results from our earlier study showing that RR Lyrae stars are present in between the Magellanic Clouds, though their three-dimensional distribution more resembles two extended overlapping structures than a strict bridge-like connection. The contours do connect in the southern parts of the Bridge, albeit on a level too low to state that an evident connection exists. To test the sample numerically, we use multi-Gaussian fitting and conclude that there is no additional population or overdensity located in the Bridge. We also try to reproduce results on the putative RR Lyrae Magellanic Bridge stream by selecting RR Lyrae candidates from Gaia Data Release 1. We show that we are not able to obtain the evident connection of the Clouds without many spurious sources in the sample, as the cuts are not able to remove artifacts without eliminating the evident connection at the same time. Moreover, for the first time, we present the Gaia Data Release 2 RR Lyrae stars in the Magellanic Bridge area and show that their distribution matches our results

    The OGLE Collection of Variable Stars. One Thousand Heartbeat Stars in the Galactic Bulge and Magellanic Clouds

    Get PDF
    We present a collection of 991 heartbeat star (HBS) candidates found in the Optical Gravitational Lensing Experiment (OGLE) project data archive. We discuss the selection process of the HBS candidates and the structure of the catalog itself. It consists of 512 stars located toward the Galactic bulge (GB), 439 stars located in the Large Magellanic Cloud (LMC), and 40 in the Small Magellanic Cloud (SMC). The collection contains two large groups of HBSs with different physical properties. The main distinction between the two groups is the evolutionary status of the primary star. The first group of about 100 systems contains a hot main-sequence (MS) or a Hertzsprung-gap primary star, while the second group of about 900 systems includes a red giant (RG). For each star, we provide two-decade-long time-series photometry, in the Cousins II- and Johnson VV-band filters, obtained by the OGLE project. We also present basic observational information as well as orbital parameters derived from the light curve modeling.Comment: 15 pages, 10 figures, 5 tables, submitted to AAS Journals. The full machine-readable tables and links to the catalog will be available after the acceptance of the pape

    OGLE-2018-BLG-0532Lb: Cold Neptune With Possible Jovian Sibling

    Get PDF
    We report the discovery of the planet OGLE-2018-BLG-0532Lb, with very obvious signatures in the light curve that lead to an estimate of the planet-host mass ratio q=Mplanet/Mhost1×104q=M_{\rm planet}/M_{\rm host}\simeq 1\times10^{-4}. Although there are no obvious systematic residuals to this double-lens/single-source (2L1S) fit, we find that χ2\chi^2 can be significantly improved by adding either a third lens (3L1S, Δχ2=81\Delta\chi^2=81) or second source (2L2S, Δχ2=65\Delta\chi^2=65) to the lens-source geometry. After thorough investigation, we conclude that we cannot decisively distinguish between these two scenarios and therefore focus on the robustly-detected planet. However, given the possible presence of a second planet, we investigate to what degree and with what probability such additional planets may affect seemingly single-planet light curves. Our best estimates for the properties of the lens star and the secure planet are: a host mass M0.25MM\sim 0.25\,M_\odot, system distance DL1D_L\sim 1\,kpc and planet mass mp,1=8Mm_{p,1}= 8\,M_\oplus with projected separation a1,=1.4a_{1,\perp}=1.4\,au. However, there is a relatively bright I=18.6I=18.6 (and also relatively blue) star projected within <50<50\,mas of the lens, and if future high-resolution images show that this is coincident with the lens, then it is possible that it is the lens, in which case, the lens would be both more massive and more distant than the best-estimated values above.Comment: 48 pages, 9 figures, 7 table
    corecore