University of Minnesota
School of Physics & Astronomy

Cosmology Lunchtime Seminar

Monday, January 30th 2017
12:15 pm:
Speaker: Burcin Mutlu-Pakdil, UMN
Subject: Discovery of an extremely rare galaxy: PGC 1000714

Non-barred ringed galaxies are among the ideal galaxies to study the role of both the internal dynamics of galaxies and the physics of accretion/interaction mechanisms. An especially interesting ring case is Hoag's Object with its peculiar morphology: an elliptical-like core with a nearly perfect outer ring, and no signs of bar and stellar disc. Hoag-type galaxies, which bear strong resemblance to Hoag's Object, are extremely rare and their origin is still debated. Our recent work has revealed a unique case for Hoag-type galaxies: PGC 1000714 presents strong resemblance to Hoag's Object in the optical and near-ultraviolet bands,with an additional structure — a second inner ring, which is more diffuse, and redder than the outer ring. Such peculiar systems help our understanding of galaxy formation in general, since they represent extreme cases, providing clues on formation mechanisms.

In the first part of my talk, I will simply overview the concept of ringed galaxies and introduce Hoag-type galaxies. Then, I will present my work on PGC 1000714 and finally conclude with a discussion about the implications of our findings.

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