An X-ray/SDSS sample

Abstract

Aims. The connection between the growth of super-massive black holes (SMBHs) and the evolution of their host galaxies is nowadays well established, although the underlying mechanisms explaining their mutual relations are still debated. Multi-phase fast, massive outflows have been postulated to play a crucial role in this process. The aim of this work is to constrain the nature and the fraction of outflowing gas in active galactic nuclei (AGNs) as well as the nuclear conditions possibly at the origin of such phenomena. Methods. We present a large spectroscopic sample of X-ray detected SDSS AGNs at z < 0.8 with a high signal-to-noise ratio in the [O III]λ5007 line to unveil the faint wings of the emission profile associated with AGN-driven outflows. We used X-ray and optical flux ratio diagnostics to select the sample. We derived physical and kinematic characterization by re-analysing optical (and X-ray) spectra. Results. We derive the incidence of ionized (∼40%) and atomic (<1%) outflows covering a wide range of AGN bolometric luminosity from 10 42 to 10 46 erg/s. We also derive bolometric luminosities and X-ray bolometric corrections to test whether the presence of outflows is associated with an X-ray loudness, as suggested by our recent results obtained by studying high-z QSOs. Conclusions. We study the relations between the outflow velocity inferred from [O III] kinematic analysis and different AGN power tracers, such as black hole mass (M BH ), [O III], and X-ray luminosity. We show a well-defined positive trend between outflow velocity and L X , for the first time, over a range of 5 order of magnitudes. Overall, we find that in the QSO-luminosity regime and at M BH > 10 8 M the fraction of AGNs with outflows becomes >50%. Finally, we discuss our results about X-ray bolometric corrections and outflow incidence in cold and ionized phases in the context of an evolutionary sequence allowing two distinct stages for the feedback phase: first, an initial stage characterized by X-ray/optical obscured AGNs, in which the atomic gas is still present in the ISM and the outflow processes involve all the gas components and, second, a later stage associated with unobscured AGNs, in which the line of sight has been cleaned and the cold components have been heated or exhausted.

BAT AGN Spectroscopic Survey – XIX. Type 1 versus type 2 AGN dichotomy from the point of view of ionized outflows

“…The velocity offset of the broad wing is defined as ∆v= (v05+v95) 2 and the velocity shift respect to the velocity peak (v p =v50) of the whole line is given by |∆v|−v p . Once we have the velocities, following Perna et al (2017), we consider a velocity threshold of v max =650 km s −1 to discriminate between kinematics dominated by gravitational broadening and outflow processes. This criterion is applied to the maximum velocities estimated from both the parametric and non-parametric methods.…”

“…In particular, our thresholds to distinguish winds from gravitational kinematics make our outflow selection criterion more restrictive, in line with the lower fractions found. Perna et al (2017) selected a sample that includes both type 1 and type 2 AGN by cross-matching 2-10 keV detections from archival XMM-Newton and Chandra data with the SDSS DR12, and adopting the non-parametric method described in Section 4.1. We find similar outflow fractions for the various AGN types as Perna et al (2017).…”

“…Perna et al (2017) selected a sample that includes both type 1 and type 2 AGN by cross-matching 2-10 keV detections from archival XMM-Newton and Chandra data with the SDSS DR12, and adopting the non-parametric method described in Section 4.1. We find similar outflow fractions for the various AGN types as Perna et al (2017). If we further split the fraction of outflows by velocity shift, we find comparable fractions of blue and redshifted outflows in type 1 AGN, while redshifted outflows are more frequently detected in our work by a factor of 8.…”

“…Numerous efforts have been done to test the occurrence of ionized outflows, finding them in a large fraction of SDSS AGN, from ∼20-40% to ∼50-70% depending on the AGN type (Balmaverde et al 2016;Harrison et al 2016;Perna et al 2017;Véron-Cetty et al 2001;Woo et al 2016Woo et al , 2017Rakshit & Woo 2018).…”

Ionized-gas Kinematics Along the Large-scale Radio Jets in Type-2 AGNs

“…The ionized gas outflows may be observationally the most straightforward signatures to investigate whether and to what degree AGN can affect the ISM of their host galaxy. The velocity of [O III] λ5007 emission line is of particular interest for probing such outflows (e.g., Zamanov et al 2002, Komossa et al 2008, Cresci et al 2015, Cicone et al 2016, Harrison et al 2016, Yuan et al 2016, Karouzos et al 2016a, Concas et al 2017, Perna et al 2017. The spatiallyintegrated [O III] lines of AGNs have been observed to be blue or redshifted with respect to low-ionization lines (e.g., Boroson 2005), which is presumably due to the combined effect of outflows and dust extinction (Crenshaw et al 2010.…”