# LOFAR first look at the giant radio galaxy 3C 236

## TL;DR

This study uses LOFAR observations at 143 MHz to analyze the giant radio galaxy 3C 236, revealing detailed spectral index maps, hotspot structures, and insights into the source's activity history and environmental interactions.

## Contribution

First high-resolution low-frequency spectral index maps of 3C 236, revealing complex hotspot structures and spectral steepening patterns, advancing understanding of giant radio galaxy morphology and activity.

## Key findings

- Confirmed inner hotspot in NW lobe
- Discovered triple hotspot in SE lobe indicating intermittent activity
- Spectral steepening in northern lobe's inner region

## Abstract

We have examined the giant radio galaxy 3C~236 using LOFAR at 143 MHz down to an angular resolution of 7", in combination with observations at higher frequencies. We have used the low frequency data to derive spectral index maps with the highest resolution yet at these low frequencies. We confirm a previous detection of an inner hotspot in the north-west lobe and for the first time observe that the south-east lobe hotspot is in fact a triple hotspot, which may point to an intermittent source activity. Also, the spectral index map of 3C 236 shows that the spectral steepening at the inner region of the northern lobe is prominent at low frequencies. The outer regions of both lobes show spectral flattening, in contrast with previous high frequency studies. We derive spectral age estimates for the lobes, as well as particle densities of the IGM at various locations. We propose that the morphological differences between the lobes are driven by variations in the ambient medium density as well as the source activity history.