118 research outputs found
New views on hyperplastic endometrial lesions classification – endometrial intraepithelial neoplasia (EIN)
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
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 at l=10 deg to
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
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
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
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
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 -
and Johnson -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
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 . Although there are
no obvious systematic residuals to this double-lens/single-source (2L1S) fit,
we find that can be significantly improved by adding either a third
lens (3L1S, ) or second source (2L2S, ) 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 , system distance kpc and planet mass
with projected separation au.
However, there is a relatively bright (and also relatively blue) star
projected within 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
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