Supermassive Black Hole Winds in X-rays: SUBWAYS: I. Ultra-fast outflows in quasars beyond the local Universe

• Published in: Astronomy and astrophysics (Berlin) 2023-02, Vol.670, p.A182
• Main Authors: Matzeu, G. A., Brusa, M., Lanzuisi, G., Dadina, M., Bianchi, S., Kriss, G., Mehdipour, M., Nardini, E., Chartas, G., Middei, R., Piconcelli, E., Gianolli, V., Comastri, A., Longinotti, A. L., Krongold, Y., Ricci, F., Petrucci, P. O., Tombesi, F., Luminari, A., Zappacosta, L., Miniutti, G., Gaspari, M., Behar, E., Bischetti, M., Mathur, S., Perna, M., Giustini, M., Grandi, P., Torresi, E., Vignali, C., Bruni, G., Cappi, M., Costantini, E., Cresci, G., De Marco, B., De Rosa, A., Gilli, R., Guainazzi, M., Kaastra, J., Kraemer, S., La Franca, F., Marconi, A., Panessa, F., Ponti, G., Proga, D., Ursini, F., Baldini, P., Fiore, F., King, A. R., Maiolino, R., Matt, G., Merloni, A.
• Format: Article
• Language: English
• ISSN: 0004-6361; 1432-0746
• DOI: 10.1051/0004-6361/202245036

We present a new X-ray spectroscopic study of 22 luminous (2 × 10 45 ≲ L bol /erg s −1 ≲ 2 × 10 46 ) 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 H α and Fe  XXVI Ly α ) 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 (≳0.1 c ) 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.