The four equidistant X-ray cavities in the galaxy cluster RBS 797: jet reorientation or binary AGNs?
Abstract
The galaxy cluster RBS 797 had been known from previous X-ray studies to host two pronounced X-ray cavities in the east-west (E-W) direction. Follow-up VLA radio observations of the central active galactic nucleus (AGN) uncovered different jet and lobe orientations, with radio lobes filling the E-W cavities and perpendicular jets showing emission in the north-south (N-S) direction over the same scale (∼30 kpc). We present the results of a deep Chandra observation of the cluster: with the new 427 ks total exposure, we detected of two additional, symmetric X-ray cavities in the N-S direction at nearly the same radial distance as the E-W ones. The four perpendicular X-ray cavities are associated to the different radio lobes seen in archival radio data. We derived the dynamical and radiative ages of the four cavities from X-ray and radio data, respectively, finding that the two outbursts are approximately coeval, with an age difference of ≤10 Myr between the E-W and N-S cavities. We discuss two scenarios for the origin of the two perpendicular, equidistant cavity systems: either the presence of binary AGNs that excavated coeval pairs of cavities in perpendicular directions or a fast (≤10 Myr) jet reorientation event that produced subsequent, misaligned outbursts.
- Publication:
-
44th COSPAR Scientific Assembly. Held 16-24 July
- Pub Date:
- July 2022
- Bibcode:
- 2022cosp...44.2327U