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 properties of blue supergiants are key for constraining the end of the main sequence phase, a phase during which massive stars spend most of their lifetimes. The lack of fast-rotating stars below 21.000K, a temperature around which stellar winds change in behaviour, has been proposed to be caused by enhanced mass-loss rates, which would spin down the star. Alternatively, the lack of fast-rotating stars may be the result of stars reaching the end of the main sequence. Here, we combine newly derived estimates of photospheric and wind parameters, wind terminal velocities from the literatureAdvertised on -
Massive stars, those over ten times heavier than our Sun, are the conduits of most elements of the periodic table and drive the morphological and chemical makeup of their host galaxies. Yet the origin of the most luminous and hottest stars among them, called 'blue supergiants', has been debated for many decades. Blue supergiants are strange stars. First, they are observed in large numbers, despite conventional stellar physics expecting them to live only briefly. Second, they are typically found alone, despite most massive stars being born with companions. Third, the majority of them harbourAdvertised on -
The hierarchical model of galaxy evolution suggests that mergers have a substantial impact on the intricate processes that drive stellar assembly within a galaxy. However, accurately measuring the contribution of accretion to a galaxy's total stellar mass and its balance with in situ star formation poses a persistent challenge, as it is neither directly observable nor easily inferred from observational properties. Using data from MaNGA, we present theory-motivated predictions for the fraction of stellar mass originating from mergers in a statistically significant sample of nearby galaxiesAdvertised on