Variability studies of blazars have identified in the past hints of quasi-periodic emission for different sources, although strong evidences are still lacking. The understanding of whether this emission is truly periodic or not can help to explain the structure of blazars and the emission mechanisms taking place in these objects. We present the

We present the analysis of a very high-magnification (A ∼ 900) microlensing event KMT-2019-BLG-1953. A single-lens single-source (1L1S) model appears to approximately delineate the observed light curve, but the residuals from the model exhibit small but obvious deviations in the peak region. A binary-lens (2L1S) model with a mass ratio of q ∼ 2 ×

We investigate the properties of starbursts and the influence of galaxy-galaxy interactions on star formation (SF) in a sample of 1341 objects (distances < 40 Mpc). Starbursts present long-lasting SF in circumnuclear regions, which causes an increase of the central stellar density in both interacting and non-interacting systems, and similar gas

Galaxy environment has been shown to play an important role in transforming late-type, star-forming galaxies to quiescent spheroids. This transformation is expected to be more severe for low-mass galaxies ( $M \lt 10^{10}\, \mathrm{M}_\odot$ ) in dense galaxy groups and clusters, mostly due to the influence of their past host haloes (also known as

This study is based on the 2.5D numerical simulations of the large-amplitude oscillations (LAOs) in the flux rope solar prominences. The prominence models with two different values of the initial shear angle and the density contrast were considered. In order to investigate the possible normal modes of the structure, the prominence was perturbed

For ground-based optical imaging with current CCD technology, the Poisson fluctuations in source and sky background photon arrivals dominate the noise budget and are readily estimated. Another component of noise, however, is the signal from the undetected population of stars and galaxies. Using injection of artifical galaxies into images, we