The IBISCO survey

Abstract

We present the analysis of the ALMA CO(2−1) emission line and the underlying 1.2 mm continuum of Mrk 509 with spatial resolution of ∼270 pc. This local Seyfert 1.5 galaxy, optically classified as a spheroid, is known to host an ionised disc, a starburst ring, and ionised gas winds on both nuclear (ultra-fast outflows) and galactic scales. From CO(2−1) we estimate a molecular gas reservoir of MH2 = 1.7 × 109 M⊙, located within a disc of size ∼5.2 kpc, with Mdyn = (2.0 ± 1.1) × 1010 M⊙ inclined at 44 ± 10 deg. The molecular gas fraction within the disc is μgas = 5%, consistent with that of local star-forming galaxies with similar stellar mass. The gas kinematics in the nuclear region within r ∼ 700 pc, that is only marginally resolved at the current angular resolution, suggests the presence of a warped nuclear disc. Both the presence of a molecular disc with ongoing star formation in a starburst ring, and the signatures of a minor merger, are in agreement with the scenario where galaxy mergers produce gas destabilisation, feeding both star formation and AGN activity. The spatially resolved Toomre Q-parameter across the molecular disc is in the range Qgas = 0.5 − 10, and shows that the disc is marginally unstable across the starburst ring, and stable against fragmentation at nucleus and in a lopsided ring-like structure located inside of the starburst ring. We find complex molecular gas kinematics and significant kinematics perturbations at two locations, one within 300 pc of the nucleus and one 1.4 kpc away close to the region with high Qgas, that we interpret as molecular winds with velocity v98 = 200 − 250 km s−1. The total molecular outflow rate is in the range 6.4−17.0 M⊙ yr−1 for the optically thin and thick cases, respectively. The molecular wind total kinetic energy is consistent with a multiphase momentum-conserving wind driven by the AGN with Ṗof/Ṗrad in the range 0.06−0.5. The spatial overlap of the inner molecular wind with the ionised wind, and their similar velocity suggest a cooling sequence within a multiphase wind driven by the AGN. The second outer molecular wind component overlaps with the starburst ring, and its energy is consistent with a supernova-driven wind arising from the starburst ring.

WISDOM Project – XIII. Feeding molecular gas to the supermassive black hole in the starburst AGN-host galaxy Fairall 49

“…The velocities of the putative outflow, therefore, would be significantly smaller than the galaxy escape velocity 10 (∼700 km s −1 at 𝑅 100 pc) and the gas would eventually fall back on the system in a galactic-fountain fashion. Similar results have been found in other studies of individual AGN and starburst systems, which show that the velocities of molecular gas outflows are significantly smaller than the galaxy escape velocity (Zanchettin et al 2021;Fluetsch et al 2019). This includes the iconic starburst M82 (Leroy et al 2015).…”

Polarimetric Reverberation Mapping in Medium-Band Filters

“…However, our estimate of R sc , although consistent with the estimates of the size of the dusty region obtained by two independent methods, is only ∼1.3-1.6R BLR . In general, all other estimates of the size of structures inside the central Mrk 509 parsec obtained independently indicate that R BLR is most likely overestimated, for example, due to the presence of outflows driven by AGN observed for Mrk 509 (e.g., [61]). This reveals the necessity of more intensive homogeneous monitoring in polarized and integral light.…”

Multiphase characterization of AGN winds in five local type-2 quasars

“…It has been observationally demonstrated that molecular outflows carry more mass than their ionized counterparts, at least in the local universe, and at AGN luminosities below 10 47 erg s −1 (Fiore et al 2017;Fluetsch et al 2021). However, as it happens with the ionized outflow mass rates, the values used to build the molecular gas counterpart of the scaling relations (Cicone et al 2014;Fiore et al 2017) are higher than those found for the general population of quasars (Ramos Almeida et al 2022), ULIRGs (Lamperti et al 2022), and Seyfert galaxies (Alonso-Herrero et al 2019;Domínguez-Fernández et al 2020;Zanchettin et al 2021).…”