As a considerable investment of time from various telescope facilities was dedicated toward studying the Spiderweb protocluster at z = 2.2, it so far remains one of the most extensively studied protocluster. We report here the latest results in this field, adding a new dimension to previous research on cluster formation at high redshift. Previous

Blazars display variable emission across the entire electromagnetic spectrum, with time-scales that can range from a few minutes to several years. Our recent work has shown that a sample of five blazars exhibit hints of periodicity with a global significance ${\gtrsim}2\, \sigma$ at γ-ray energies, in the range of 0.1 GeV < E < 800 GeV. In this

Aims: The BL Lac 1ES 2344+514 is known for temporary extreme properties characterised by a shift of the synchrotron spectral energy distribution (SED) peak energy ν synch, p above 1 keV. While those extreme states have only been observed during high flux levels thus far, additional multi-year observing campaigns are required to achieve a coherent

Context One of the most fundamental scaling relations in galaxies is observed between metallicity and stellar mass - the mass-metallicity relation (MZR) - although recently a stronger dependence of the gas-phase metallicity with the galactic gravitational potential (ΦZR) has been reported. Further dependences of metallicity on other galaxy

We present here binary modeling for the close binary central star of the planetary nebula Hf 2-2. While binary models for 26 close binary star systems within a planetary nebula exist, this number is far too low to perform a significant statistical analysis. In order to work towards increasing this number, and thus improving the statistical results

In this study, we look specifically at binary white dwarfs where the companion is a main sequence star. In particular, we look at very hot white dwarfs, many of which demonstrate the "hydrogen problem" in which modeling of their hydrogen absorption features, and optical features in general, do not appear to give accurate temperatures. The two