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Abstract: We give an overview of our recent integral-field-unit spectroscopy ofluminous extended emission-line regions EELRs around low-redshift quasars,including new observations of 5 fields. Previous work has shown that the mostluminous EELRs are found almost exclusively around steep-spectrum radio-loudquasars, with apparently disordered global velocity fields, and little, if any,morphological correlation with either the host-galaxy or the radio structure.Our new observations confirm and expand these results. The EELRs often showsome clouds with velocities exceeding 500 km-s, ranging up to 1100 km-s, butthe velocity dispersions, with few exceptions, are in the 30-100 km-s range.Emission-line ratios show that the EELRs are clearly photoionized by thequasars. Masses of the EELRs range up to >10^10 Msun. Essentially all of theEELRs show relatively low metallicities, and they are associated with quasarsthat, in contrast to most, show similarly low metallicities in their broad-lineregions. The two objects in our sample that do not have classical double-lobedradio morphologies 3C48, with a compact-steep-spectrum source; Mrk1014,radio-quiet, but with a weak compact-steep-spectrum source are the only onesthat appear to have recent star formation. While some of the less-luminousEELRs may have other origins, the most likely explanation for the ones in oursample is that they are examples of gas swept out of the host galaxy by alarge-solid-angle blast wave accompanying the production of the radio jets. Thetriggering of the quasar activity is almost certainly the result of the mergerof a gas-rich galaxy with a massive, gas-poor galaxy hosting the supermassiveblack hole.

Author: Hai Fu, Alan Stockton IfA, Hawaii

Source: https://arxiv.org/

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