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NASA Goddard Space Flight CenterAnna Trindade FalcãoMultiwavelength astrophysicist · Black-hole winds · AGN feedback
Continuum-subtracted HST/ACS/WFC [O III] λ5007 image of FIRST J120041.4+314745 from the left panel of published Figure 2. Elliptical semi-annuli mark constant deprojected distance from the nucleus, the green line divides the two semi-ellipses, and the orthogonal black line marks the STIS slit direction. The overlays define image-flux extraction geometry; the image itself is not a velocity map, outflow-rate measurement, or feedback measurement.
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Research article · 2021

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

MNRAS 500(1), 1491–1504 (2021)

Paper-derived processed HST/ACS observational figure · Published Figure 2 left panel

Published Figure 2, left panel. Continuum-subtracted HST/ACS/WFC [O III] λ5007 imaging of FIRST J120041.4+314745. Elliptical semi-annuli mark rings of constant deprojected distance from the nucleus under the paper's host-disc geometry; the green line divides the two semi-ellipses, and the orthogonal black line marks the STIS slit direction. Flux from these image annuli was combined with the separate long-slit spectroscopic measurements and model assumptions used to derive radial mass and energetic profiles. The image and overlays define projected morphology and extraction geometry; they are not themselves a gas-velocity map, outflow-rate measurement, kinetic-power measurement, or evidence of causal feedback.

Figure 2, left panel, from Trindade Falcão et al. 2021, “Hubble Space Telescope observations of [O III] emission in nearby QSO2s: physical properties of the ionized outflows,” MNRAS 500, issue 1, 1491–1504, DOI: 10.1093/mnras/staa3239. © 2020 The Author(s), published by Oxford University Press on behalf of the Royal Astronomical Society. HST: NASA/ESA; figure and image processing: Trindade Falcão et al. Converted from PNG to lossy WebP for presentation on Anna Trindade Falcão's non-commercial professional research website under the applicable RAS/OUP non-commercial figure-reuse basis. Exact WebP encoder settings are not recorded and deterministic regeneration is not claimed. No CC BY or broader public license is implied.

Research summary

Measured [O III] kinematics and model-dependent ionized-outflow energetics

This study extends the Fischer et al. 2018 analysis of 12 nearby luminous type 2 quasars using the same HST data. ACS/WFC continuum-subtracted [O III] imaging measures projected morphology and annular flux, while STIS G430M or G750M long-slit spectra provide spatially resolved [O III] fluxes, centroid velocities, and line profiles. Gas densities are not direct measurements: they are estimated with Cloudy 17.00 using [O III]-derived ionizing luminosities, an assumed spectral energy distribution, reddening and bolometric corrections, and a fixed ionization-parameter prescription. Ionized masses, mass-outflow rates, kinetic energies and luminosities, momenta, and momentum-flow rates additionally depend on host-disc deprojection and the assumption that slit density, column, and velocity represent each semi-annulus; these derived quantities carry approximately factor-four uncertainties. Total ionized outflow masses span approximately 4.6 × 10³–3.4 × 10⁷ M☉, peak mass-outflow rates span 9.3 × 10⁻³–10.3 M☉ yr⁻¹, and peak kinetic luminosities span approximately 3.4 × 10⁻⁸–4.9 × 10⁻⁴ of Lbol, below the 5 × 10⁻³–5 × 10⁻² range adopted by the cited efficient-feedback models. This does not establish that every gas phase lacks feedback power. The proposed recent-brightening, host-mass-profile, neutral or molecular gas, thermal-expansion, X-ray-gas, and evolutionary explanations are interpretations or possibilities rather than direct measurements. Results from the later two-object QSO2 kinematics/X-ray paper and the local type 1 QSO imaging paper are separate and are not measurements of this study.