Gas Sloshing and Bubbles in the Galaxy Group NGC 5098

Abstract

We present results from Chandra observations of the galaxy pair and associated galaxy group NGC 5098, and find evidence for both gas sloshing and AGN heating. The X-ray brightness images show diffuse emission with a spiral structure, centered on NGC 5098a, and a sharp edge in the diffuse emission surrounding much of the galaxy at about 30 kpc. The spiral structure in the X-ray surface brightness and temperature maps, the offset between the peak of the cool gas and the central AGN, and the structure of the cold front edges all suggest gas sloshing in the core. The most likely perturber is the nearby galaxy NGC 5098b, which has been stripped of its gaseous atmosphere. Detailed images of the core reveal several X-ray cavities, two of which, just north and southeast of the central AGN, correlate with radio emission and have bright X-ray rims, similar to buoyant bubbles seen in the ICM of other systems. We estimate the pressures in the bubbles and rims and show that they are roughly equal, consistent with these being young features, as suggested by their close proximity to the central AGN. We assume that the other X-ray cavities in the core, which show no correlation with existing radio observations, are ghost cavities from previous AGN outbursts. An estimate of the mechanical energy required to inflate the cavities indicates that it is sufficient to offset radiative cooling of the gas for 15 Myr. Therefore, for a typical cycle time of 10^7 yrs, the central AGN energy output is enough to balance cooling over long timescales.

Replaced with accepted version, including small correction to equations 2 & 3, conclusions unchanged

References in corpus (10)

• Heating Hot Atmospheres with Active Galactic Nuclei
• Shocks and cold fronts in galaxy clusters
• The origin of cold fronts in the cores of relaxed galaxy clusters
• Probing the Dark Matter and Gas Fraction in Relaxed Galaxy Groups with X-ray observations from Chandra and XMM
• High-energy particle acceleration at the radio-lobe shock of Centaurus A
• Chandra's View of the Ram Pressure Stripped Galaxy M86
• Chandra Observations of Nuclear Outflows in the Elliptical Galaxy NGC4552 in the Virgo Cluster
• In-depth Chandra study of the AGN feedback in Virgo elliptical galaxy M84
• Different Methods of Forming Cold Fronts in Non-Merging Clusters
• The nature of the ghost cavity in the NGC 741 group

Cited by in corpus (12)

• Feedback from Active Galactic Nuclei in Galaxy Groups
• Constraining Gas Motions in the Intra-Cluster Medium
• LOFAR Observations of X-ray Cavity Systems
• The galaxy group NGC 507: newly detected AGN remnant plasma transported by sloshing
• Metal distribution in sloshing galaxy clusters: the case of A496
• The Chandra Deep Group Survey -- cool core evolution in groups and clusters of galaxies
• Simulations of gas sloshing in galaxy cluster Abell 2052
• Merger Hydrodynamics of the Luminous Cluster RXJ1347.5-1145
• Simulating nearly edge-on sloshing in the galaxy cluster Abell 2199
• Sloshing Cold Fronts in Galaxy Cluster Abell 2566
• Structure and kinematics of the interacting group NGC 5098/5096
• The strongest cool core in REXCESS: Missing X-ray cavities in RXC J2014.8-2430