Complex molecular gas kinematics in the inner 5 kpc of 4C12.50 as seen by ALMA

Abstract

The nearby system 4C12.50, also known as IRAS 13451+1217 and PKS 1345+12, is a merger of gas-rich galaxies with infrared and radio activity. It has a perturbed interstellar medium (ISM) and a dense configuration of gas and dust around the nucleus. The radio emission at small (∼100 pc) and large (∼100 kpc) scales, as well as the large X-ray cavity in which the system is embedded, are indicative of a jet that could have affected the ISM. We carried out observations of the CO(1-0), (3-2), and (4-3) lines with the Atacama Large Millimeter Array (ALMA) to determine basic properties (i.e., extent, mass, and excitation) of the cold molecular gas in this system, including its already-known wind. The CO emission reveals the presence of gaseous streams related to the merger, which result in a small (∼4kpc-wide) disk around the western nucleus. The disk reaches a rotational velocity of 200 km s −1 , and has a mass of 3.8(±0.4)×10 9 M . It is truncated at a gaseous ridge north of the nucleus that is bright in [O iii]. Regions with high-velocity CO emission are seen at signal-to-noise ratios of between 3 and 5 along filaments that radially extend from the nucleus to the ridge and that are bright in [O iii] and stellar emission. A tentative wind detection is also reported in the nucleus and in the disk. The molecular gas speed could be as high as 2200 km s −1 and the total wind mass could be as high as 1.5(±0.1)×10 9 M . Energetically, it is possible that the jet, assisted by the radiation pressure of the active nucleus or the stars, accelerated clouds inside an expanding bubble.

Cool outflows in galaxies and their implications

“…4.5, we discussed in detail four specific cases (Cen A, IC 5063, NGC 1266, and NGC 1377), but evidence is found for other galaxies with radio jets (e.g. Dasyra and Combes 2012;Guillard et al 2012;Morganti and Oosterloo 2018;Murthy et al 2019;Fotopoulou et al 2019;Zovaro et al 2019;Fernández-Ontiveros et al 2019). It is generally found that the jet-driven outflowing gas in the molecular phase is as massive as the neutral-atomic phase, or even more massive, and largely exceeding the mass in the ionized phase.…”

High molecular gas content and star formation rates in local galaxies that host quasars, outflows and jets

“…These observations; however, are unable to rule out a more localised impact, which can sometimes be observed using spatially-resolved molecular gas measurements (e.g. Salomé et al 2017;Rosario et al 2018;Fotopoulou et al 2019;Ramakrishnan et al 2019;Shin et al 2019;Lutz et al 2020). Furthermore, we can not rule out that these processes will have an impact on the global molecular gas supply on longer timescales.…”

“…Molecular gas outflows traced by CO gas have been identified in both radio and quasar mode AGN (see e.g. Cicone et al 2014;King & Pounds 2015;Morganti et al 2015;Bischetti et al 2019;Fotopoulou et al 2019;Oosterloo et al 2019;Lutz et al 2020;Veilleux et al 2020). However these outflows typically only represent ∼10 per cent of the molecular gas luminosity (see e.g.…”

Cool Outflows in Galaxies and their Implications

“…In Section 4.5, we discussed in detail four specific cases (Cen A, IC 5063, NGC 1266, and NGC 1377), but evidence is found for other galaxies with radio jets (e.g. Dasyra and Combes 2012;Guillard et al 2012;Morganti and Oosterloo 2018;Murthy et al 2019;Fotopoulou et al 2019;Zovaro et al 2019;Fernández-Ontiveros et al 2019). It is generally found that the jet-driven outflowing gas in the molecular phase is as massive as the neutral-atomic phase, or even more massive, and largely exceeding the mass in the ionized phase.…”