We find a distinct stellar population in the counterrotating and kinematically decoupled core of the isolated massive elliptical galaxy NGC 1700. Coinciding with the edge of this core, we find a significant change in the slope of the gradient of various representative absorption line indices. Our age estimate for this core is markedly younger than the main body of the galaxy. We find lower values for the age, metallicity, and Mg/Fe abundance ratio in the center of this galaxy when we compare them with other isolated elliptical galaxies with similar velocity dispersion. We discuss the different possible scenarios that might have lead to the formation of this younger kinematically decoupled structure and conclude that, in light of our findings, the ingestion of a small stellar companion on a retrograde orbit is the most favored.
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We present the results of our spatially resolved investigation into the interplay between the ages of the stellar populations and the kinematics of the warm ionised outflows in the well-studied type II quasar Markarian 34. Utilising integral field spectroscopic (IFS) data, we determine the spatial distribution of the young stellar population (YSP; age < 100 Myr) using spectral synthesis modelling. We also employ the 5007 [OIII] emission line as a tracer of the warm ionised gas kinematics. We demonstrate a spatial correlation between the outer edges of the advancing side of the outflow and an
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Classical novae are cataclysmic binary star systems in which the matter of a companion star is accreted on a white dwarf. Accumulation of hydrogen in a layer eventually causes a thermonuclear explosion on the surface of the white dwarf, brightening the white dwarf to ~100.000 solar luminosities and triggering ejection of the accumulated matter. Novae provide the extreme conditions required to accelerate particles, electrons or protons, to high energies. Here we present the detection of gamma rays by the MAGIC telescopes from the 2021 outburst of RS Ophiuchi, a recurrent nova with a red giant
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Many of the most basic and important physical phenomena are determined by a set of “fundamental constants”, whose values are experimentally known to high accuracy. A key aspect is to know whether they are “universal constants”, i.e., whether they have always had the same value across the Universe and throughout its history. Here we made use of data from the ESPRESSO spectrograph on the Very Large Telescope (VLT) in order to determine the value of the fine structure constant 8 thousand million years ago (when the Universe was just 40% its current age) by measuring spectral transitions in a
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