An Active Galactic Nucleus Driven Shock in the Intracluster Medium Around the Radio Galaxy 3c 310

Abstract

We present results from a 57.6 ks Chandra observation of the cluster gas associated with the fat-double radio galaxy 3C 310. We find a surface brightness discontinuity in the gas outside the southern radio lobe that we attribute to a shock driven by the supersonic inflation of this lobe ∼180 kpc from the nucleus. Modeling the surface brightness/density jump, the shock has Mach number 1.5-1.9, depending on the assumptions one makes about the density profile and the nature of the energy input. There are not sufficient counts in the image to detect conclusively the temperature jump associated with the shock. The total mechanical energy of the outburst is 5 × 10 60 erg. Assuming a Mach 1.9 shock, the age of the outburst is ∼100 million yrs, and the time-averaged power of the outburst is ∼1.3 × 10 45 erg s −1 . The power input is 100 times greater than the radiative losses of the gas within the radius of the shock. Most importantly, the equivalent heat input due to the entropy increase is roughly 10% of the thermal energy of the gas to the radius of the shock. 3C 310 is another example where regular outbursts of the observed strength with a duty cycle of 0.1 could offset the radiative losses of the gas near the Bondi radius and regulate feedback. We also detect a cool filamentary X-ray arm along the eastern periphery of the southern radio lobe. This arm is probably composed of low-entropy gas dredged up in the inflation of the radio plasma, similar to features seen in M87.

Detection of a pair of prominent X-ray cavities in Abell 3847

“…The observed offset between the X-ray cavities and radio lobes may be either due to the projection effect of radio emission or the physical offset between the X-ray cavities and radio lobes due to two different episodic AGN outburst. This peculiar nature has been rarely seen in very few other clusters such as 3C 310 (Kraft et al 2012), NGC 1316 (Lanz et al 2010), Abell 4059 (Heinz et al 2002), MS0735.6+742 ). The radio jets emitted along North and South directions of 3C 444 were seen to bend towards East and West directions at a distance of ∼ 8 arcsec (∼ 20 kpc) from the nuclear region of the central galaxy (Figure 8).…”

The link between accretion mode and environment in radio-loud active galaxies

“…3C 310 (PKS 1502+26) is a LERG with wide FRI plumes and a disturbed environment containing a large cavity, filamentary structure and a shock front at about 180 kpc from the nucleus (Kraft et al 2012). The emission extends beyond the observing chip, but we were able to use one of the outer chips to model the background for the spectral analysis.…”

AGN feedback in galaxy group 3C 88: cavities, shock, and jet reorientation

“…However, the total cavity power is consistent with the value used in the plot. We included four additional systems, PKS B2152-699 (Worrall et al 2012, the cavity power is estimated using the buoyant rise time as for other systems in the plot), 3C 310 (Kraft et al 2012), 3C 444 (Croston et al 2011) and Abell 3581 (Canning et al 2013) in the plot. The large solid red circle denotes the location of 3C 88, whose cavity power is among the largest in galaxy groups (please see Section 6.4 for discussion).…”

“…The brightest central galaxies (BCGs) of clusters and groups are more likely to host a radio-loud AGN (e.g., Burns 1990;Best et al 2007;Sun 2009;Mittal et al 2009). Highresolution X-ray observations have revealed disturbed structures, such as shocks and cavities, in the cores of clusters, groups, and elliptical galaxies (e.g., Bîrzan et al 2004Bîrzan et al , 2008Nulsen et al 2005a,b;Forman et al 2005;Fabian et al 2006;Croston et al 2008Croston et al , 2011Baldi et al 2009;Randall et al 2015;Kraft et al 2012;Su et al 2017). These features are caused by the radio AGN jets.…”