Hubble Space Telescope observations of [O iii] emission in nearby QSO2s: Physical properties of the ionized outflows

We use Hubble Space Telescope/Space Telescope Imaging Spectrograph long-slit G430M and G750M spectra to analyse the extended [O iii] λ5007 emission in a sample of 12 nearby (z 1.6 × 1045 erg s-1) QSO2s. The purpose of the study is to determine the properties of the mass outflows of ionized gas and their role in active galactic nucleus feedback. We measure fluxes and velocities as functions of radial distances. Using cloudy models and ionizing luminosities derived from [O iii] λ5007, we are able to estimate the densities for the emission-line gas. From these results, we derive masses of [O iii]-emitting gas, mass outflow rates, kinetic energies, kinetic luminosities, momenta, and momentum flow rates as a function of radial distance for each of the targets. For the sample, masses are several times $10^{3}$-$10{7}\, {\rm M {\odot }}$ and peak outflow rates are from 9.3 × 10-3 to $10.3\, {\rm M{\odot }}\, {\rm yr^{-1}}$. The peak kinetic luminosities are (3.4 × 10-8)-(4.9 × 10-4) of the bolometric luminosity, which does not approach the (5.0 × 10-3)-(5.0 × 10-2) range required by some models for efficient feedback. For Mrk 34, which has the largest kinetic luminosity of our sample, in order to produce efficient feedback there would have to be 10 times more [O iii]-emitting gas than that we detected at its position of maximum kinetic luminosity. Three targets show extended [O iii] emission, but compact outflow regions. This may be due to different mass profiles or different evolutionary histories. © 2021 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.Immediate accessThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Hubble Space Telescope Observations of Extended [O iii]λ 5007 Emission in Nearby QSO2s: New Constraints on AGN Host Galaxy Interaction

We present a Hubble Space Telescope survey of extended [O iii] λ5007 emission for a sample of 12 nearby (z < 0.12), luminous Type 2 quasars (QSO2s), which we use to measure the extent and kinematics of their AGN-ionized gas. We find that the size of the observed [O iii] regions scale with luminosity in comparison to nearby, less luminous Seyfert galaxies and radially outflowing kinematics to exist in all targets. We report an average maximum outflow radius of ~600 pc, with gas continuing to be kinematically influenced by the central active galactic nucleus (AGN) out to an average radius of ~1130 pc. These findings question the effectiveness of AGNs being capable of clearing material from their host bulge in the nearby universe and suggest that disruption of gas by AGN activity may prevent star formation without requiring evacuation. Additionally, we find a dichotomy in our targets when comparing [O iii] radial extent and nuclear FWHM, where QSO2s with compact [O iii] morphologies typically possess broader nuclear emission lines

Drug refractory epilepsy in brain damage: effect of dextromethorphan on EEG in four patients.

High doses of dextromethorphan (20-42 mg/kg/day) were given to four critically ill children with seizures and frequent epileptiform abnormalities in the EEG that were refractory to antiepileptic drugs. Their acute diseases (hypoxia, head trauma and hypoxia, neurodegenerative disease, hypoglycaemia) were thought to be due in part to N-methyl-D-aspartate (NMDA) receptor mediated processes. Treatment with dextromethorphan, an NMDA receptor antagonist, was started between 48 hours and 14 days after the critical incident. In three patients the EEG improved considerably within 48 hours and seizures ceased within 72 hours. In the patient with neurodegenerative disease the effect on the EEG was impressive, but the seizures were not controlled. Despite the improvement of the EEG the clinical outcome was poor in all children: three died in the critical period or due to the progressing disease; the patient with hypoglycaemia survived with severe neurological sequelae. Plasma concentrations of dextromethorphan varied between 74-1730 ng/ml and its metabolite dextrorphan varied between 349-3790 ng/ml. In one patient corresponding concentrations in CSF were lower than those in plasma. The suppression of epileptic discharges by the doses of dextromethorphan given suggests that such doses are sufficient to block NMDA receptors