Deep H{\alpha} Observations of NGC 253: a Very Extended and Possibly Declining Rotation Curve?
Abstract
This study presents a deep H{\alpha} kinematical analysis of the Sculptor Group galaxy NGC253. The Fabry-Perot data were taken with the 36-cm Marseille Telescope in La Silla, Chile, using an EMCCD detector. Typical emission measures of ~0.1 cm^-6 pc are reached. The observations allow the detection of the Diffuse Ionized Gas component through [N II] emission at very large radii of 11.5', 12.8' and 19.0', on the receding side of the galaxy. No H{\alpha} emission is observed at radii larger than the neutral component (11.5'). The very extended rotation curve confirms previous results and shows signs of a significant decline, on the order of 30 per cent vmax . Using the rotation data, mass models are constructed with and without the outer [N II] data points, and similar results are found. The declining part of the rotation curve is very well modeled, and seems to be truly declining.
Cite
@article{arxiv.1009.1177,
title = {Deep H{\alpha} Observations of NGC 253: a Very Extended and Possibly Declining Rotation Curve?},
author = {J. Hlavacek-Larrondo and C. Carignan and O. Daigle and M. -M. de Denus-Baillargeon and M. Marcelin and B. Epinat and O. Hernandez},
journal= {arXiv preprint arXiv:1009.1177},
year = {2015}
}
Comments
Accepted for publication in MNRAS. 16 pages, 10 figures, 4 tables