Quasar feedback and the origin of radio emission in radio-quiet quasars

By N. Zakamska, Jenny E. Greene. 2014

250 citations recorded by the source corpus.

We conduct kinematic analysis of the SDSS spectra of 568 obscured luminous quasars, with the emphasis on the kinematic structure of the [OIII]5007 emission line. [OIII] emission tends to show blueshifts and blue excess, which indicates that at least part of the narrow-line gas is undergoing an organized outflow. The velocity width containing 90% of line power ranges from 370 to 4780 km/sec, suggesting outflow velocities up to 2000 km/sec. The velocity width of the [OIII] emission is positively correlated with the radio luminosity among the radio-quiet quasars. We propose that radio emission in radio-quiet quasars is due to relativistic particles accelerated in the shocks within the quasar-driven outflows; star formation in quasar hosts is insufficient to explain the observed radio emission. The median radio luminosity of the sample of nu L_nu[1.4GHz] = 10^40 erg/sec suggests a median kinetic luminosity of the quasar-driven wind of L_wind=3x10^44 erg/sec, or about 4% of the estimated median bolometric luminosity L_bol=8x10^45 erg/sec. Furthermore, the velocity width of [OIII] is positively correlated with mid-infrared luminosity, which suggests that outflows are ultimately driven by the radiative output of the quasar. As the outflow velocity increases, some emission lines characteristic of shocks in quasi-neutral medium increase as well, which we take as further evidence of quasar-driven winds propagating into the interstellar medium of the host galaxy. None of the kinematic components show correlations with the stellar velocity dispersions of the host galaxies, so there is no evidence that any of the gas in the narrow-line region of quasars is in dynamical equilibrium with the host galaxy. Quasar feedback appears to operate above the threshold luminosity of L_bol=3x10^45 erg/sec.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/0285c264ff53f14d8464b62e983b61fe089ea5fc

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Citations in the corpus

Discovery of extreme [O III] λ5007 Å outflows in high-redshift red quasars (2015, methodology): “Rather, we use the fits to compute the non-parametric measures of the [O III] λ5007 Å profile, following Zakamska & Greene (2014) and many other authors (e.g. Whittle 1985a; Veilleux 1991a).”
AGN outflows and feedback twenty years on (2018, unknown): “Indirect methods are also now being explored, such as assuming that radio emission traces shocks in the ISM driven by quasar winds[69, 58] or by detecting a Sunyaev-Zeldovich signal in the far-infrared spectral energy distributions of quasars[70].”
A ∼50,000 M⊙ SOLAR MASS BLACK HOLE IN THE NUCLEUS OF RGG 118 (2015, background): “[OIII] λ5007 is significantly brighter than [SII], and can reveal the presence of wings (Mullaney et al. 2013; Zakamska & Greene 2014).”
The Karl G. Jansky Very Large Array Sky Survey (VLASS). Science Case and Survey Design (2019, background): “It is not clear whether the radio emission is from failed jets, star formation, or shocks (e.g., Kimball et al. 2011; Condon et al. 2013b; Zakamska & Greene 2014; White et al. 2017), indeed there is evidence that all three may contribute.”
Kiloparsec-scale outflows are prevalent among luminous AGN: outflows and feedback in the context of the overall AGN population (2014, background): “…above that expected from their ongoistarformation (e.g., Helou et al. 1985; Condon et al. 1995), thatm y indicate radio emission due to an AGN either in form of a radiocore or radio jets (e.g., see Del Moro et al. 2013 and references there-in) or due to shocks (e.g., Zakamska & Greene 2014).”