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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…
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-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…
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…
OGLE-ing the Magellanic System: Three-Dimensional Structure of the Clouds and the Bridge Using Classical Cepheids
Anna M. Jacyszyn-Dobrzeniecka, D. M. Skowron, P. Mróz +10
We analyzed a sample of 9418 fundamental-mode and first-overtone Classical Cepheids from the OGLE-IV Collection of Classical Cepheids. The distance to each Cepheid was calculated u…