Supermassive Black Hole Winds in X-rays: SUBWAYS. I. Ultra-fast outflows in quasars beyond the local Universe
Maiolino, R.; Merloni, A.; Fiore, F.; Bianchi, S.; Cappi, M.; Costantini, E.; Mehdipour, M.; Ponti, G.; Behar, E.; Marconi, A.; Guainazzi, M.; Vignali, C.; Gilli, R.; Piconcelli, E.; Comastri, A.; Brusa, M.; Grandi, P.; Dadina, M.; Gaspari, M.; Miniutti, G.; Tombesi, F.; De Marco, B.; Kraemer, S.; Lanzuisi, G.; King, A. R.; Matt, G.; Nardini, E.; Perna, M.; Cresci, G.; Petrucci, P. O.; De Rosa, A.; Chartas, G.; Panessa, F.; Krongold, Y.; Longinotti, A. L.; Mathur, S.; Bruni, G.; Middei, R.; Matzeu, G. A.; Torresi, E.; Giustini, M.; Kriss, G.; Ursini, F.; Zappacosta, L.; Kaastra, J.; Proga, D.; Baldini, P.; Ricci, F.; La Franca, F.; Luminari, A.; Bischetti, M.; Gianolli, V.
Italy, Spain, United States, France, Mexico, Israel, Netherlands, United Kingdom, Germany
Abstract
We present a new X-ray spectroscopic study of 22 luminous (2 × 1045 ≲ Lbol/erg s−1 ≲ 2 × 1046) active galactic nuclei (AGNs) at intermediate redshifts (0.1 ≲ z ≲ 0.4), as part of the SUpermassive Black hole Winds in the x-rAYS (SUBWAYS) sample, mostly composed of quasars and type 1 AGNs. Here, 17 targets were observed with XMM-Newton in 2019-2020, and the remaining 5 are from previous observations. The aim of this large campaign (1.45 Ms duration) is to characterise the various manifestations of winds in the X-rays driven from supermassive black holes in AGNs. In this paper we focus on the search for and characterisation of ultra-fast outflows (UFOs), which are typically detected through blueshifted absorption troughs in the Fe K band (E > 7 keV). By following Monte Carlo procedures, we confirm the detection of absorption lines corresponding to highly ionised iron (e.g. Fe XXV Hα and Fe XXVI Lyα) in 7 out of 22 sources at the ≳95% confidence level (for each individual line). The global combined probability of such absorption features in the sample is > 99.9%. The SUBWAYS campaign, based on XMM-Newton, extends to higher luminosities and redshifts than previous local studies on Seyferts. We find a UFO detection fraction of ∼30% of the total sample, which is in agreement with previous findings. This work independently provides further support for the existence of highly ionised matter propagating at mildly relativistic speeds (≳0.1c) in a considerable fraction of AGNs over a broad range of luminosities, which is believed to play a key role in the self-regulated AGN feeding-feedback cycle, as also supported by hydrodynamical multi-phase simulations.