Powerful Yet Lonely: Is 3C 297 a High-redshift Fossil Group?

Abstract The environment of the high-redshift ( z = 1.408), powerful radio-loud galaxy 3C 297 has several distinctive features a cluster. Among them, characteristic halo hot gas revealed by Chandra X-ray observations. In addition, radio map obtained with Very Large Array shows bright hotspot in northwestern direction, created interaction active galactic nucleus (AGN) jet arising from its environment. images, emission cospatial lobe is detected, and peaks at position hotspot. extended, complex observed our new data largely unrelated to structure. Despite having attributes cluster, no companion galaxies have been identified 39 spectra neighboring targets Gemini Multi-Object Spectrograph. None 19 for which redshift was determined lies same distance as 297. optical spectral analysis spectrum reveals an isolated Type II AGN. We also detected line broadening [O ii ] ? 3728 FWHM about 1700 km s ?1 possible shifts up 500–600 . postulate that host fossil group, most stellar mass merged into single object, leaving behind halo.