The RINGS Survey III: Medium-Resolution Halpha Fabry-Perot Kinematic Dataset

TL;DR

This paper presents medium-resolution Halpha Fabry-Perot spectroscopic data for 14 nearby spiral galaxies, deriving detailed velocity fields and rotation curves to study galaxy structure and test cosmological models.

Contribution

It provides high-resolution kinematic maps and rotation curves for a sample of galaxies, enhancing understanding of their mass distribution and disk geometry.

Findings

Rotation curves agree with previous measurements

Projection angles match photometric data

Galaxies likely have non-oval disks

Abstract

The distributions of stars, gas, and dark matter in disk galaxies provide important constraints on galaxy formation models, particularly on small spatial scales (<1kpc). We have designed the RSS Imaging spectroscopy Nearby Galaxy Survey (RINGS) to target a sample of 19 nearby spiral galaxies. For each of these galaxies, we are obtaining and modeling Halpha and H1~21~cm spectroscopic data as well as multi-band photometric data. We intend to use these models to explore the underlying structure and evolution of these galaxies in a cosmological context, as well as whether the predictions of LCDM are consistent with the mass distributions of these galaxies. In this paper, we present spectroscopic imaging data for 14 of the RINGS galaxies observed with the medium spectral resolution Fabby-Perot etalon on the Southern African Large Telescope. From these observations, we derive high spatial resolution line of sight velocity fields of the Halpha line of excited hydrogen, as well as maps and azimuthally averaged profiles of the integrated Halpha and [NII] emission and oxygen abundances. We then model these kinematic maps with axisymmetric models, from which we extract rotation curves and projection geometries for these galaxies. We show that our derived rotation curves agree well with other determinations and the similarity of the projection angles with those derived from our photometric images argues against these galaxies having intrinsically oval disks.