2017ApJ...848...42K

We have shown that Lyα blobs (LABs) may still exist even at z∼0.3, about seven billion years later than most other LABs known (Shirmer et al.). Their luminous Lyα and [O III] emitters at z∼0.3 offer new insights into the ionization mechanism. This paper focuses on the two X-ray brightest LABs at z∼0.3, SDSS J0113+0106 (J0113) and SDSS J1155-0147 (J1155), comparable in size and luminosity to "B1," one of the best-studied LABs at z 2. Our NuSTAR hard X-ray (3-30 keV) observations reveal powerful active galactic nuclei (AGN) with L_2–10keV=(0.5–3)×10⁴⁴ erg s^–1. J0113 also faded by a factor of ∼5 between 2014 and 2016, emphasizing that variable AGN may cause apparent ionization deficits in LABs. Joint spectral analyses including Chandra data constrain column densities of N_H=5.1_–3.3^+3.1×10²³ cm^–2 (J0113) and N_H=6.0_–1.1^+1.4×10²² cm^–2 (J1155). J0113 is likely buried in a torus with a narrow ionization cone, but ionizing radiation is also leaking in other directions, as revealed by our Gemini/GMOS 3D spectroscopy. The latter shows a bipolar outflow over 10 kpc, with a peculiar velocity profile that is best explained by AGN flickering. X-ray analysis of J1155 reveals a weakly absorbed AGN that may ionize over a wide solid angle, consistent with our 3D spectra. Extinction-corrected [O III] log-luminosities are high, ∼43.6. The velocity dispersions are low, ∼100-150 km s^–1, even at the AGN positions. We argue that this is a combination of high extinction hiding the turbulent gas and previous outflows that have cleared the escape paths for their successors.