Modeling Tidal Streams and Tidal Tails around Galaxies Using Deep Wendelstein Imaging Data

TL;DR

This paper introduces a novel Gaussian-based modeling technique to analyze and measure the photometric properties of tidal streams and tails around galaxies using deep imaging data, providing precise measurements and insights into their origins.

Contribution

The study develops and applies an innovative Gaussian model for tidal feature analysis, enabling accurate measurement of their brightness, width, and structural parameters from deep imaging data.

Findings

Measured surface brightness of streams ~26.25 g' mag arcsec$^{-2}$

Streams are dimmer than tails in the sample

Progenitors likely include dwarfs, early-type galaxies, or disks

Abstract

From the $\Lambda$ cold dark matter paradigm it is expected that galaxies merge and grow in their environments. These processes form various tidal features depending on the merger mass ratio, orbital parameters, and gas richness. We inspected 170 $g'$-band Abell cluster observations from the 2.1m Fraunhofer-Teleskop Wendelstein and identify 111 of such features from which we select nine streams and five tails. A fast and innovative technique was developed for determining their photometric properties. The model is a Gaussian, including higher-order moments to describe the light profile in slices perpendicular to the elongation direction. From these models, FWHM apertures are generated. The method was developed, tested, and applied on the selected features and corresponding $g$- and $r$-band data from the Legacy Survey DR10. Regarding the novel modeling approach, we can measure surface and total brightnesses with precisions of 4% and 7%, respectively. Mean stream width precision, which also translates to the mean $R_\mathrm{e}$ along the feature is on average within 3% uncertainty. The measured streams have on average a surface brightness of $\sim26.25$ $g'$ mag arcsec$^{-2}$ and are dimmer than the tails in our sample ($\sim25.14$ $g'$ mag arcsec$^{-2}$). We infer that the progenitors of our streams can come from dwarfs, early-type galaxies or disks, based on the streams structural parameters. Furthermore, brightnesses and colors of the streams and tails are consistent with those of galaxies that populate the red sequence in the Coma cluster within $2\sigma$.