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

19 February 2025 ApJ

Jan-Niklas Pippert, Matthias Kluge and Ralf Bender

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 \(2.1\,\)m 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 Re along the feature is on average within \(3\%\) uncertainty. The measured streams have on average a surface brightness of \(\sim 26.25\,g'\) mag arcsec\(^{-2}\) and are dimmer than the tails in our sample (\(\sim 25.14\,g'\) 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\(\sigma\).

TOI-5108 b and TOI 5786 b: Two transiting sub-Saturns detected and characterized with TESS, MaHPS and SOPHIE

07 February 2025 A&A

Luis Thomas, Guillaume Hébrard, Hanna Kellermann, et al.

"We report the discovery and characterization of two sub-Saturns from the Transiting Exoplanet Survey Satellite (TESS) using high-resolution spectroscopic observations from the MaHPS spectrograph at the Wendelstein Observatory and the SOPHIE spectrograph at the Haute-Provence Observatory. [...]"

I observed some of the spectra for the radial velocity measurements during my shifts at the Wendelstein observatory.

Confirmation of four hot Jupiters detected by TESS using follow-up spectroscopy from MaHPS at Wendelstein together with NEID and TRES

13 December 2024 A&A

Juliana Ehrhardt, Luis Thomas, Hanna Kellermann, et al.

"We report the confirmation and characterization of four hot Jupiter-type exoplanets initially detected by TESS: TOI-1295 b, TOI-2580 b, TOI-6016 b, and TOI-6130 b. Using observations with the high-resolution echelle spectrograph MaHPS on the \(2.1\,\)m telescope at Wendelstein Observatory, together with NEID at Kitt Peak National Observatory and TRES at the Fred Lawrence Whipple Observatory, we confirmed the planetary nature of these four planet candidates. [...]"

I observed some of the spectra for the radial velocity measurements during my shifts at the Wendelstein observatory.