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arXiv · astro-ph/0310567

NGC 4261 and NGC 4697: rejuvenated elliptical galaxies

A. Zezas·L. Hernquist·G. Fabbiano·J. Miller
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Abstract

Chandra images present evidence for a non-uniform spatial distribution of discrete X-ray sources in the elliptical galaxy NGC 4261. This non-uniform distribution is inconsistent with the optical morphology of NGC 4261 at greater than a 99.9% confidence level. Similar evidence is seen in one more elliptical galaxy (NGC 4697; 98% confidence level) out of five cases we investigated. NGC 4261 and NGC 4697 have old stellar populations (9-15 Gyrs) and fine structure parameters of 1 and 0 respectively, suggesting no recent merging activity. On the basis of simulations of galaxy interactions, we propose that the X-ray sources responsible for the non-uniform distribution are associated with young stellar populations, related to the rejuvenating fall-back of material in tidal tails onto a relaxed merger remnant, or shock induced star-formation along the tidal tails.

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A. Zezas, L. Hernquist, G. Fabbiano, J. Miller. 2003-10-20. NGC 4261 and NGC 4697: rejuvenated elliptical galaxies. https://doi.org/10.1086/380895

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