Related papers: Systematic evaluation of variability detection met…
Context: After the successful launch of the Spectrum-Roentgen-Gamma (SRG) mission in July 2019, eROSITA, the soft X-ray instrument aboard SRG, performed scanning observations of a large contiguous field, namely the eROSITA Final Equatorial…
The derivation of radial velocities from large numbers of spectra that typically result from survey work, requires automation. However, except for the classical cases of slowly rotating late-type spectra, existing methods of measuring…
With an adaptive optics imaging survey of 148 B6-A7 stars, we have tested the hypothesis that unresolved lower-mass companions are the source of the unexpected X-ray detections of stars in this spectral type range. The sample is composed of…
General Relativity predicts only two tensor polarization modes for gravitational waves while at most six possible polarization modes are allowed in general metric theory of gravity. The number of polarization modes is determined by the…
We develop a new method of extracting simultaneous measurements of weak lensing shear and a local rotation of the plane of polarization using observations of resolved radio sources. We show that the direction of polarization is…
We present a 100 yr optical lightcurve of the recently discovered supersoft X-ray source RX~J0019.8+2156 as deduced from photographic plates of Harvard and Sonneberg Observatory. Apart from the periodic orbital variations two different…
A new approach to detect change points based on differential smoothing and multiple testing is presented for long data sequences modeled as piecewise constant functions plus stationary ergodic Gaussian noise. As an application of the STEM…
We present a sophisticated statistical point-source foreground model for low-frequency radio Epoch of Reionization (EoR) experiments using the 21 cm neutral hydrogen emission line. Motivated by our understanding of the low-frequency radio…
We have carried out a multifrequency analysis of the radio variability of blazars, exploiting the data obtained during the extensive monitoring programs carried out at the University of Michigan Radio Astronomy Observatory (UMRAO, at 4.8,…
A wide range of phenomena, from explosive transients to active galactic nuclei, exhibit variability at radio wavelengths on timescales of a few years. Characterizing the rate and scale of variability in the radio sky can provide keen…
We discuss an algorithm whereby the massive galaxy clusters detected in the SRG/eROSITA all-sky survey are identified and their photometric redshifts are estimated. For this purpose, we use photometric redshift estimates for galaxies and…
The ultra-precise photometric space satellite MOST (Microvariability and Oscillations of STars) will provide the first opportunity to measure the albedos and scattered light curves from known short-period extrasolar planets. Due to the…
XMM-Newton provides unprecedented insight into the X-ray Universe, recording variability information for hundreds of thousands of sources. Manually searching for interesting patterns in light curves is impractical, requiring an automated…
Gamma-ray bursts (GRBs) have variable lightcurves. Although most models attribute the observed variability to one physical origin (e.g. central engine activity, clumpy circumburst medium, relativistic turbulence), some models invoke two…
The Laser Interferometer Space Antenna (LISA) guarantees the detection of gravitational waves by monitoring a handful of known nearby galactic binary systems, the so-called ``verification binaries''. We consider the most updated information…
Fast and reliable localization of high-energy transients is crucial for characterizing the burst properties and guiding the follow-up observations. Localization based on the relative counts of different detectors has been widely used for…
Chandra observations of 17 nearby galaxies were analysed and 166 bright sources with X-ray counts > 100, were chosen for temporal analysis. Fractional root mean square variability amplitudes were estimated for lightcurves binned at ~ 4 ksec…
Accurate camera calibration is a precondition for many computer vision applications. Calibration errors, such as wrong model assumptions or imprecise parameter estimation, can deteriorate a system's overall performance, making the reliable…
Characterising spectral variability of radio sources is a technique that offers the ability to determine the astrophysics of the intervening media, source structure, emission and absorption processes. We present broadband (0.072--10 GHz)…
The origin of fast flux variability in blazars is a long-standing problem, with many theoretical models proposed to explain it. In this study, we focus on BL Lacertae to model its spectral energy distribution (SED) and broadband light…