Title
A 100 kpc ram pressure tail trailing the group galaxy NGC 2276
Date Issued
2024
Author(s)
Roberts, I. D.
van Weeren, R. J.
de Gasperin, F.
Botteon, A.
Edler, H. W.
Matijević, L.
Tomičić, N.
DOI
10.1051/0004-6361/202450672
10.48550/arXiv.2406.09221
Abstract
We present the discovery of a 100 kpc low-frequency radio tail behind the nearby group galaxy, NGC 2276. The extent of this tail is a factor of ten larger than previously reported from higher-frequency radio and X-ray imaging. The radio morphology of the galaxy disc and tail suggest that the tail was produced via ram-pressure stripping, cementing NGC 2276 as the clearest known example of ram-pressure stripping in a low-mass group. With multi-frequency imaging, we extract radio continuum spectra between ∼50 MHz and 1.2 GHz as a function of projected distance along the tail. All of the spectra are well fit by a simple model of spectral ageing due to synchrotron and inverse-Compton losses. From these fits we estimate a velocity of 870 km s<SUP>‑1</SUP> for the stripped plasma across the plane of the sky, and a three-dimensional orbital velocity of 970 km s<SUP>‑1</SUP> for NGC 2276. The orbital speed that we derive is in excellent agreement with the previous estimates from an X-ray shock analysis, despite the completely independent methodology.
Subjects
galaxies: groups: individual: NGC 2300
galaxies: individual: NGC 2276
galaxies: magnetic fields
galaxies: spiral
galaxies: starburst
galaxies: star formation
Astrophysics - Astrophysics of Galaxies