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.
Advertised on
References
2011, ApJ, 732L, 33K
It may interest you
-
The development of the latest generation of Imaging Atmospheric Cherenkov Telescopes (IACTs) over recent decades has led to the discovery of new extreme astrophysical phenomena in the very-high-energy (VHE, E > 100 GeV) gamma-ray regime. Time-domain and multi-messenger astronomy are inevitably connected to the physics of transient VHE emitters, which show unexpected (and mostly unpredictable) flaring or exploding episodes at different timescales. These transients often share the physical processes responsible for the production of the gamma-ray emission, through cosmic-ray accelerationAdvertised on -
Despite the fundamental role that dark matter halos play in our theoretical understanding of galaxy formation and evolution, the interplay between galaxies and their host dark matter halos remains highly debated from an observational perspective. This lack of conclusive observational evidence ultimately arises from the inherent difficulty of reliably measuring dark matter (halo) properties. Based on detailed dynamical modeling of nearby galaxies, in this work we proposed a novel observational approach to quantify the potential effect that dark matter halos may have in modulating galaxyAdvertised on -
Light bridges are elongated and bright structures protruding into the umbra of sunspots. The presence of light bridges has a significant role in the evolution of sunspots and the heating of their overlying atmosphere. Therefore, investigating these structures is crucial to understanding fundamental aspects of sunspots. By applying a novel code based on deep-learning algorithms called SICON to spectropolarimetric observations acquired with the Hinode satellite, we computed atmospheric parameters that allowed us to infer the variation of the physical properties of light bridges on a geometricAdvertised on