705 citations · 12k across the 299 of their papers we have counts for
31 papers · 1 filter
A Method to Measure the Unbiased Decorrelation Timescale of the AGN Variable Signal from Structure Functions
Szymon Kozłowski
A simple, model-independent method to quantify the stochastic variability of active galactic nuclei (AGNs) is the structure function (SF) analysis. If the SF for the timescales sho…
The OGLE Collection of Variable Stars. Eclipsing Binaries in the Magellanic System
M. Pawlak, I. Soszyński, A. Udalski +10
We present the collection of eclipsing binaries in the Large and Small Magellanic Clouds, based on the OGLE survey. It contains 48605 systems, 40204 belonging to the LMC and 8401 t…
Variable classification in the LSST era: Exploring a model for quasi-periodic light curves
J. C. Zinn, C. S. Kochanek, S. Kozłowski +10
LSST is expected to yield ~10^7 light curves over the course of its mission, which will require a concerted effort in automated classification. Stochastic processes provide one mea…
Gaia and Variable Stars
A. Udalski, I. Soszyński, D. M. Skowron +9
We present a comparison of the Gaia DR1 samples of pulsating variable stars - Cepheids and RR Lyrae type - with the OGLE Collection of Variable Stars aiming at the characterization…
Limitations on the recovery of the true AGN variability parameters using Damped Random Walk modeling
Szymon Kozłowski
Context: The damped random walk (DRW) stochastic process is nowadays frequently used to model aperiodic light curves of AGNs. A number of correlations between the DRW model paramet…
OGLE-2015-BLG-0196: Ground-based Gravitational Microlens Parallax Confirmed By Space-Based Observation
C. Han, A. Udalski, A. Gould +20
In this paper, we present the analysis of the binary gravitational microlensing event OGLE-2015-BLG-0196. The event lasted for almost a year and the light curve exhibited significa…
OGLE-ing the Magellanic System: Three-Dimensional Structure of the Clouds and the Bridge Using RR Lyrae Stars
Anna M. Jacyszyn-Dobrzeniecka, D. M. Skowron, P. Mróz +10
We present a three-dimensional analysis of a sample of 22 859 type RR Lyrae stars in the Magellanic System from the OGLE-IV Collection of RR Lyrae stars. The distance to each…
Virial Black Hole Mass Estimates for 280,000 AGNs from the SDSS Broad-Band Photometry and Single Epoch Spectra
Szymon Kozłowski
We use the Sloan Digital Sky Survey (SDSS) Quasar Data Release 12 (DR12Q), containing nearly 300,000 AGNs, to calculate the monochromatic luminosities at 5100Å, 3000Å, and 1350Å, d…
OGLE Collection of Star Clusters. New Objects in the Outskirts of the Large Magellanic Cloud
M. Sitek, M. K. Szymański, D. M. Skowron +13
The Magellanic System (MS), consisting of the Large Magellanic Cloud (LMC), the Small Magellanic Cloud (SMC) and the Magellanic Bridge (MBR), contains diverse sample of star cluste…
The awakening of a classical nova from hibernation
P. Mroz, A. Udalski, P. Pietrukowicz +9
Cataclysmic variable stars (CVs) are close binary systems consisting of a white dwarf (primary) that is accreting matter from a low-mass companion star (secondary). From time to ti…
Anomalous Double-Mode RR Lyrae Stars in the Magellanic Clouds
I. Soszyński, R. Smolec, W. A. Dziembowski +11
We report the discovery of a new subclass of double-mode RR Lyrae stars in the Large and Small Magellanic Clouds. The sample of 22 pulsating stars have been extracted from the late…
OGLE-ing the Magellanic System: Photometric Metallicity from Fundamental Mode RR Lyrae Stars
D. M. Skowron, I. Soszyński, A. Udalski +9
In an era of extensive photometric observations, the catalogs of RR Lyr type variable stars number tens of thousands of objects. The relation between the iron abundance [Fe/H] and…
A Search for Stellar-Mass Black Holes via Astrometric Microlensing
J. R. Lu, E. Sinukoff, E. O. Ofek +2
While dozens of stellar mass black holes have been discovered in binary systems, isolated black holes have eluded detection. Their presence can be inferred when they lens light fro…
The OGLE Collection of Variable Stars. Over 45 000 RR Lyrae Stars in the Magellanic System
I. Soszyński, A. Udalski, M. K. Szymański +9
We present the largest collection of RR Lyrae stars in the Magellanic System and in its foreground. The sample consists of 45 451 RR Lyr stars, of which 39 082 were detected toward…
OGLE-2016-BLG-0596Lb: High-Mass Planet From High-Magnification Pure-Survey Microlensing Event
P. Mróz, C. Han, A. Udalski +24
We report the discovery of a high mass-ratio planet , i.e., 13 times higher than the Jupiter/Sun ratio. The host mass is not presently measured but can be determined or st…
OGLE-2012-BLG-0950Lb: The First Planet Mass Measurement from Only Microlens Parallax and Lens Flux
N. Koshimoto, A. Udalski, J. P. Beaulieu +38
We report the discovery of a microlensing planet OGLE-2012-BLG-0950Lb with the planet/host mass ratio of . A long term distortion detected in both MOA and…
OGLE-2015-BLG-0479LA,B: Binary Gravitational Microlens Characterized by Simultaneous Ground-based and Space-based Observation
C. Han, A. Udalski, A. Gould +60
We present a combined analysis of the observations of the gravitational microlensing event OGLE-2015-BLG-0479 taken both from the ground and by the {\it Spitzer Space Telescope}. T…
OGLE-2015-BLG-0051/KMT-2015-BLG-0048Lb: a Giant Planet Orbiting a Low-mass Bulge Star Discovered by High-cadence Microlensing Surveys
C. Han, A. Udalski, A. Gould +20
We report the discovery of an extrasolar planet detected from the combined data of a microlensing event OGLE-2015-BLG-0051/KMT-2015-BLG-0048 acquired by two microlensing surveys. D…
First simultaneous microlensing observations by two space telescopes: & reveal a brown dwarf in event OGLE-2015-BLG-1319
Y. Shvartzvald, Z. Li, A. Udalski +90
Simultaneous observations of microlensing events from multiple locations allow for the breaking of degeneracies between the physical properties of the lensing system, specifically…
Space-based Microlens Parallax Observation As a Way to Resolve the Severe Degeneracy between Microlens-parallax and Lens-orbital Effect
C. Han, A. Udalski, C. -U. Lee +23
In this paper, we demonstrate the severity of the degeneracy between the microlens-parallax and lens-orbital effects by presenting the analysis of the gravitational binary-lens eve…
OGLE16aaa - a Signature of a Hungry Super Massive Black Hole
Łukasz Wyrzykowski, M. Zieliński, Z. Kostrzewa-Rutkowska +22
We present the discovery and first three months of follow-up observations of a currently on-going unusual transient detected by the OGLE-IV survey, located in the centre of a galax…
OGLE Study of the Sagittarius Dwarf Spheroidal Galaxy and its M54 Globular Cluster
A. Hamanowicz, P. Pietrukowicz, A. Udalski +9
We use the fundamental-mode RR Lyr-type variable stars (RRab) from OGLE-IV survey to draw a 3D picture of the central part of the tidally disrupted Sagittarius Dwarf Spheroidal (Sg…
Revisiting Stochastic Variability of AGNs with Structure Functions
Szymon Kozłowski
Discrepancies between reported structure function (SF) slopes and their overall flatness as compared to expectations from the damped random walk (DRW) model, which generally well d…
Discovery of a Gas giant Planet in Microlensing Event OGLE-2014-BLG-1760
A. Bhattacharya, D. P. Bennett, I. A. Bond +41
We present the analysis of the planetary microlensing event OGLE-2014-BLG-1760, which shows a strong light curve signal due to the presence of a Jupiter mass-ratio planet. One unus…