We report the clearest detection to date of dusty torus signatures in a Weak-Line Radio Galaxy ( WLRG ) .
The deep Spitzer InfraRed Spectrograph ( IRS ) rest-frame mid-infrared ( MIR ) spectrum of the WLRG PKS 0043-42 ( z=0.116 ) shows a clear spectral turnover at \lambda \ga 20 µm suggestive of warm dust , as well as a 9.7 µm silicate absorption feature .
In addition , the hard X-ray results , based on Chandra data , strongly support a picture in which PKS 0043 - 42 has a torus and accretion disc more typical of Strong-Line Radio Galaxies ( SLRGs ) .
The MIR and X-ray spectra are markedly different from those of other WLRGs at similar redshifts , and here we show that the former can be successfully fitted with clumpy torus models with parameters characteristic of Type-2 AGN tori : close to edge-on ( i =74° ) and relatively broad ( \sigma =60° ) , with an outer radius of 2 pc , N _ { H } =1.6 \pm ^ { 0.2 } _ { 0.1 } \times 10 ^ { 23 } ~ { } cm ^ { -2 } , and AGN bolometric luminosity L _ { bol } ^ { AGN } = 1.6 \pm ^ { 0.2 } _ { 0.1 } \times 10 ^ { 44 } ~ { } erg~ { } s ^ { -1 } .
The presence of a compact torus in PKS 0043-42 provides evidence that this WLRG is fuelled by cold , rather than hot , gas accretion .
We suggest that WLRGs are a diverse population , and PKS 0043-42 may represent a type of radio galaxy in which the AGN activity has been recently re-triggered as a consequence of intermittent gas supply , or in which the covering factor of the Narrow-Line Region ( NLR ) clouds is relatively low .