Institute of Astrophysics and Space Sciences | University of Porto | 2016 Nov 22
[img3="True color image of galaxy NGC 1167, overlaid with contours depicting the spiral-like star-forming regions. Credit: JM Gomes et al. (2016 A&A)"]http://www.iastro.pt/press/CALIFA_Spiral-like/Fig1a.png[/img3][hr][/hr]Using data from the SDSS and CALIFA surveys, a team3 of astronomers, led by Jean Michel Gomes and Polychronis Papaderos from the Instituto de Astrofísica e Ciências do Espaço (IA), in Portugal, discovered in the optical faint star-forming spiral-arm-like features in the periphery of nearby early-type galaxies. This work was presented yesterday, during the 2nd SELGFIS Advanced School on Integral-Field Spectroscopic Data Analysis , ongoing in Madrid until the 25th of November 2016.
Usually, star-forming regions are blue areas, HII-regions that house short-lived massive blue stars, embedded in the disk section of spiral galaxies. In contrast, Elliptical and Lenticular galaxies (historically referred to as early-type galaxies) are composed of old stars with reddish colors, and are thought to be “dead” spheroids, no longer giving birth to new stars.
However, the CALIFA study led by the IA team has now discovered in the optical spiral features in the outskirts of three nearby early-type galaxies, which points to a still ongoing inside-out growth. This adds valuable observational insight into the origin and evolution of spiral structures in old spheroidal galaxies. ...
Spiral-Like Star-Forming Patterns in CALIFA Early-Type Galaxies - J. M. Gomes et al
- Astronomy & Astrophysics 585:A92 (2016 Jan) DOI: 10.1051/0004-6361/201525974
arXiv.org > astro-ph > arXiv:1511.00744 > 02 Nov 2015