XRISM/Resolve probes a possible “raining” absorber in Mrk 509

¹ INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Gobetti 101, I-40129 Bologna, Italy
² INAF – Osservatorio Astronomico di Brera, Via Bianchi 46, I-23807 Merate (LC), Italy
³ INAF – Osservatorio Astronomico di Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Italy
⁴ INAF – Istituto di Astrofisica e Planetologia Spaziali, via Fosso del Cavaliere 100, I-00133 Roma, Italy
⁵ Institut de Recherche en Astrophysique et Planétologie, 9 avenue du Colonel Roche, Toulouse 31028, France
⁶ INAF – Osservatorio Astrofisco di Arcetri, largo E. Fermi 5, 50127 Firenze, Italy
⁷ Dipartimento di Matematica e Fisica, Università degli Studi Roma Tre, Via della Vasca Navale 84, I-00146 Roma, Italy
⁸ Department of Physics and Astronomy, College of Charleston, Charleston, SC 29424, USA
⁹ SRON Netherlands Institute for Space Research, Leiden, The Netherlands
¹⁰ Leiden Observatory, University of Leiden, P.O. Box 9513, NL-2300 RA, Leiden, The Netherlands
¹¹ Cahill Center for Astronomy & Astrophysics, California Institute of Technology, 1216 East California Boulevard, Pasadena, CA 91125, USA
¹² Quasar Science Resources SL for ESA, European Space Astronomy Centre (ESAC), Science Operations Department, 28692 Villanueva de la Cañada, Madrid, Spain
¹³ Space Science Data Center, Agenzia Spaziale Italiana, Via del Politecnico snc, 00133 Roma, Italy
¹⁴ Université Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
¹⁵ INAF–IASF Palermo, Via U. La Malfa 153, I-90146 Palermo, Italy
¹⁶ Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Av. Ejército Libertador 441 Santiago, Chile
¹⁷ Dipartimento di Fisica e Astronomia ‘Augusto Righi’, Università degli Studi di Bologna, Via Gobetti 93/2, I-40129 Bologna, Italy

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Received: 23 February 2026
Accepted: 4 May 2026

Abstract

Context. X-ray spectroscopy of active galactic nuclei (AGNs) offers unique insights into the reprocessing of radiation and the gas dynamics near supermassive black holes. The Seyfert 1 galaxy Mrk 509 is an ideal laboratory for these studies. It is in fact known for its complex iron K emission and one of the four or five AGNs to date in which evidence of transient, blue- and redshifted absorption features indicative of high-velocity flows has been detected in X-rays.

Aims. We present the first high-resolution 2–10 keV spectrum of Mrk 509 obtained with the XRISM/Resolve calorimeter. Our primary goals are to disentangle the narrow and broad emission features and to place stringent constraints on the kinematics and physical locations of circumnuclear gas flows, specifically searching for signatures of accretion and feedback.

Methods. We analyzed 106 ks of XRISM/Resolve data, complemented by simultaneous XMM-Newton and NuSTAR observations, which we used to constrain the broadband continuum. We modeled the spectra using self-consistent reflection models for the continuum and the emission lines, and employed photoionized plasma models to characterize discrete, ionized absorption features.

Results. The XRISM/Resolve spectrum reveals a narrow Fe Kα core resolved with σ ≃ 10 eV (v_FWHM∼ 1100 km/s). The best-fit model includes a broader component with σ ∼ 450 eV. We also find tentative evidence of discrete absorption features at rest-frame energies of E ∼ 6.2 keV. When modeled as an ionized absorber (with a significance of ∼3.6σ), the data suggest the gas is redshifted relative to the systemic velocity, corresponding to an inflow of material with v_in ∼ 11 000 km s⁻¹, located within the inner few thousand gravitational radii.

Conclusions. The narrow Fe Kα emission is consistent with an origin in the dusty torus, while the broad component arises from broad-line-region scales or the accretion disk (R ∼ 30–120 r_g). This scenario is strongly corroborated by our relativistic reflection modeling, which restricts the inner edge of the emitting region to distances greater than 27 r_g. If confirmed by future observations, the high-velocity inflow would likely represent dense, fragmented clumps of a “failed wind” raining back onto the accretion disk, providing potential direct evidence that nonstandard accretion processes may coexist with canonical disk-like flows in the inner regions of AGNs.