%0 Generic %1 bischetti2019gentle %A Bischetti, M. %A Piconcelli, E. %A Feruglio, C. %A Fiore, F. %A Carniani, S. %A Brusa, M. %A Cicone, C. %A Vignali, C. %A Bongiorno, A. %A Cresci, G. %A Mainieri, V. %A Maiolino, R. %A Marconi, A. %A Nardini, E. %A Zappacosta, L. %D 2019 %K ALMA outflow %T The gentle monster PDS 456: the kpc scale molecular outflow and its implications for QSO feedback %U http://arxiv.org/abs/1903.10528 %X We report on the first ALMA observation of the CO(3$-$2) and rest-frame ~340 GHz continuum emission in PDS 456, which is the most luminous, radio-quiet QSO in the local Universe ($z$~0.18), with a bolometric luminosity $L_\rm Bol\sim10^47$ erg s$^-1$. ALMA angular resolution allowed us to map scales as small as ~700 pc. The molecular gas reservoir, traced by the core of the very bright CO(3$-$2) emission line, is distributed in a compact rotating disk, with size of ~1.3 kpc, seen close to face-on ($i$~25 deg). Fast CO(3$-$2) emission in the velocity range $vın-1000,+500$ km s$^-1$ is also present. Specifically, we detect several blue-shifted clumps out to ~5 kpc from the nucleus, in addition to a compact ($Rłesssim1.2$ kpc), broad emission component. These components reveal a galaxy-wide molecular outflow, with a total mass $M_mol^out\sim2.5\times10^8$ $M_ødot$ and a mass outflow rate $M_mol\sim290$ $M_ødot$ yr$^-1$. The corresponding depletion time is ~8 Myr, shorter than the rate at which the molecular gas is converted into stars, indicating that the detected outflow is potentially able to quench star-formation in the host. The momentum flux of the molecular outflow normalised to the radiative momentum output (i.e. $L_\rm Bol/c$) is $łesssim1$, comparable to that of the X-ray ultra-fast outflow (UFO) detected in PDS 456. This is at odds with the expectations for an energy-conserving expansion suggested for most of the large-scale outflows detected in low-luminosity AGN so far. We suggest three possible scenarios that may explain this observation: (i) in very luminous AGN such as our target the molecular gas phase is tracing only a fraction of the total outflowing mass; (ii) a small coupling between the shocked gas by the UFO and the host-galaxy ISM (iii) AGN radiation pressure may play an important role in driving the outflow.

@misc{bischetti2019gentle, abstract = {We report on the first ALMA observation of the CO(3$-$2) and rest-frame ~340 GHz continuum emission in PDS 456, which is the most luminous, radio-quiet QSO in the local Universe ($z$~0.18), with a bolometric luminosity $L_{\rm Bol}\sim10^{47}$ erg s$^{-1}$. ALMA angular resolution allowed us to map scales as small as ~700 pc. The molecular gas reservoir, traced by the core of the very bright CO(3$-$2) emission line, is distributed in a compact rotating disk, with size of ~1.3 kpc, seen close to face-on ($i$~25 deg). Fast CO(3$-$2) emission in the velocity range $v\in[-1000,+500]$ km s$^{-1}$ is also present. Specifically, we detect several blue-shifted clumps out to ~5 kpc from the nucleus, in addition to a compact ($R\lesssim1.2$ kpc), broad emission component. These components reveal a galaxy-wide molecular outflow, with a total mass $M_{\rm mol}^{\rm out}\sim2.5\times10^8$ $M_{\odot}$ and a mass outflow rate $\dot{M}_{\rm mol}\sim290$ $M_{\odot}$ yr$^{-1}$. The corresponding depletion time is ~8 Myr, shorter than the rate at which the molecular gas is converted into stars, indicating that the detected outflow is potentially able to quench star-formation in the host. The momentum flux of the molecular outflow normalised to the radiative momentum output (i.e. $L_{\rm Bol}/c$) is $\lesssim1$, comparable to that of the X-ray ultra-fast outflow (UFO) detected in PDS 456. This is at odds with the expectations for an energy-conserving expansion suggested for most of the large-scale outflows detected in low-luminosity AGN so far. We suggest three possible scenarios that may explain this observation: (i) in very luminous AGN such as our target the molecular gas phase is tracing only a fraction of the total outflowing mass; (ii) a small coupling between the shocked gas by the UFO and the host-galaxy ISM (iii) AGN radiation pressure may play an important role in driving the outflow.}, added-at = {2019-03-27T15:18:50.000+0100}, author = {Bischetti, M. and Piconcelli, E. and Feruglio, C. and Fiore, F. and Carniani, S. and Brusa, M. and Cicone, C. and Vignali, C. and Bongiorno, A. and Cresci, G. and Mainieri, V. and Maiolino, R. and Marconi, A. and Nardini, E. and Zappacosta, L.}, biburl = {https://www.bibsonomy.org/bibtex/2d9a5cc10987da1f0b60a86beef564ffc/heh15}, description = {The gentle monster PDS 456: the kpc scale molecular outflow and its implications for QSO feedback}, interhash = {319a1b10ef345cf1b406be5639844240}, intrahash = {d9a5cc10987da1f0b60a86beef564ffc}, keywords = {ALMA outflow}, note = {cite arxiv:1903.10528Comment: Submitted to A&A}, timestamp = {2019-03-27T15:18:50.000+0100}, title = {The gentle monster PDS 456: the kpc scale molecular outflow and its implications for QSO feedback}, url = {http://arxiv.org/abs/1903.10528}, year = 2019 }