Multi-layered Fast Wind observed in XMM-Newton snapshot of Seyfert 1 Markarian 877

TL;DR

This study tackles how AGN winds regulate galaxy evolution by analyzing an 18 ks XMM-Newton snapshot of the Seyfert 1 galaxy Mrk 877 with photoionization modeling. Three Ultra-fast Outflow components are identified, each with distinct ionization states and speeds up to ~0.10 c, inferred through the SPEX pion framework and supporting line diagnostics. The derived AMD slope m ≈ 1.18 yields a density profile α ≈ 1.54, consistent with magnetically driven Blandford-Payne winds, and the fastest component carries ≥5% of the Eddington luminosity, indicating significant galaxy-scale feedback; momentum considerations suggest a hybrid radiative+magnetic driving scenario. The results highlight a multi-phase, potentially clumpy wind structure and emphasize the need for deeper, higher-resolution spectroscopy (e.g., XRISM) to fully resolve wind geometry and assess the wind’s impact on the host galaxy.

Abstract

Ultra Fast Outflows (UFOs) are powerful, highly ionized winds launched from the innermost regions of Active Galactic Nuclei (AGNs), reaching velocities of 0.03 -- 0.3 c and playing a key role in AGN feedback. We present a photoionization analysis of an 18 ks \xmm\ snapshot of the Seyfert 1 AGN Mrk 877, revealing three distinct UFO components with line-of-sight velocities of $0.10^{+0.005}_{-0.005}~c$ , $ 0.04^{+0.005}_{-0.004}~c$ , and $0.05^{+0.005}_{-0.004}~c$. These components span a broad range of ionization parameters and column densities, producing absorption features across both soft and hard X-ray bands. Even under the most conservative assumption for the volume filling factor, the fastest component exceeds $5\%$ of the Eddington luminosity, making it capable of driving strong galaxy-scale feedback. The soft X-ray UFO component, despite its lower ionization, shares a similar velocity as a higher-ionization component, hinting at a two-phase medium likely shaped by clumpiness or interactions with ambient material. The density profile inferred from the Absorption Measurement Distributions (AMD) and the positive trend between outflow momentum rate and radiation momentum flux suggest that wind is powered by a combination of radiative and magnetic driving.

Figures (4)

• Figure 1: LEFT: XMM-Newton/PN 18 ks snapshot of Mrk 877 in the source frame, fit with a simple power-law. The strong flux deficits between 0.7--1.4 keV and 6.4--8.4 keV indicate multiple ionized partially covering absorption components. RIGHT: Best-fit model using three distinct UFO components with the $pion$ photoionization model in SPEX. The green, magenta, and blue curves represent absorption from low- to high-ionization zones. These components are detected at $5\sigma$, $4\sigma$, and $> 10\sigma$. The red curve shows the total best-fit model.
• Figure 2: Top Panel: The observed X-ray spectrum of Mrk 877 with the best-fit model (red curve), plotted relative to the underlying power-law continuum (orange curve) to highlight the absorption features. The contributions from each of the three "$pion$" components are shown separately by blue, magenta, and green curve, respectively. Bottom Three Panel: The transmission models of each "$pion$" component plotted individually, with vertical lines marking the most prominent absorption lines from different elements. The bottom panel for "$pion_{\#3}$" is plotted in a range of 0.3 -- 3 keV, while all other panels are plotted in a range of 0.3 -- 10 keV.
• Figure 3: The values of best-fit column densities ($N_H$), LOS outflow velocities ($v_z$), turbulence velocities ($\sigma_v$), and the covering factors ($f_{\mathrm{cov}}$) of the wind as a function of best-fit ionization parameter $\xi$. The best-fit line between column density and ionization parameter is shown in the top panel, with shaded regions indicating the $1\sigma$ confidence level. $m$ and $\alpha$ are the best slope and the associated density profile index with its $1\sigma$ uncertainty.
• Figure 4: The outflow momentum rate ($\dot{p}_{out}$) as a function of the momentum flux of the radiation field ($\dot{p}_{rad}$). The transparent triangles represent values multiplied by the minimum volume filling factors. The solid and dashed lines are the best fit lines for the data with unity and minimum volume filling factors. The shaded regions indicating the $1\sigma$ confidence level. The best fit slope $m$ is presented in the legend. The dotted lines marked the equality between $\dot{p}_{out}$ and $\dot{p}_{rad}$