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Central UV Spikes in two Galactic Spheroids

Michele Cappellari·Francesco Bertola·David Burstein·Lucio M. Buson·Laura Greggio·Alvio Renzini
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Abstract

FOS spectra and FOC photometry of two centrally located, UV-bright spikes in the elliptical galaxy NGC 4552 and the bulge-dominated early spiral NGC 2681, are presented. These spectra reveal that such point-like UV sources detected by means of HST within a relatively large fraction ~15% of bulges can be related to radically different phenomena. While the UV unresolved emission in NGC 4552 represents a transient event likely induced by an accretion event onto a supermassive black hole, the spike seen at the center of NGC 2681 is not variable and it is stellar in nature.

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Michele Cappellari, Francesco Bertola, David Burstein, Lucio M. Buson, Laura Greggio, Alvio Renzini. 1999-01-27. Central UV Spikes in two Galactic Spheroids. https://arxiv.org/abs/astro-ph/9901381

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