The space density of z>4 blazars

High redshift blazars are an important class of Active Galactic Nuclei (AGN) that can provide an independent estimate of the supermassive black-hole mass function in high redshift radio-loud AGN without the bias due to absorption along the line-of-sight. Using the Cosmic Lens All Sky Survey (CLASS) we built a complete radio flux-limited sample of high redshift (z>4) blazars suitable for statistical studies. By combining dedicated optical observations and the SDSS spectroscopic database, we obtained a sample of 26 blazar candidates with a spectroscopic redshift above 4. On the basis of their radio spectrum we distinguish between blazars and QSO with a Gigahertz Peaked Spectrum (GPS) like spectrum. Out of the 18 confirmed blazars 14 constitute a completely identified, flux-limited sample down to a magnitude of 21 (AB). Using this complete sample we derive a space density of blazars with 4<z<5.5 of rho=0.13 (+0.05,-0.03) Gpc^-3. This is the first actual estimate of the blazar space density in this range of redshift. This value is in good agreement with the extrapolation of the luminosity function and cosmological evolution based on a sample of flat-spectrum radio quasars selected at lower redshifts and it is consistent with a cosmological evolution peaking at z$\sim$2 similar to radio-quiet QSO. We do not confirm, instead, the presence of a peak at z~4 in the space density evolution, recently suggested using an X-ray selected sample of blazars. It is possible that this extreme peak of the evolution is present only among the most luminous blazars.Comment: 14 pages, accepted for publication on MNRAS (https://doi.org/10.1093/mnras/sty3526

Testing the blast-wave AGN feedback scenario in MCG-03-58-007

We report the first Atacama large millimeter/submillimeter array observations of MCG-03-58-007, a local ($z=0.03236\pm0.00002$, this work) AGN ($L_{AGN}\sim10^{45}~\rm erg~s^{-1}$), hosting a powerful X-ray ultra-fast ($v=0.1c$) outflow (UFO). The CO(1-0) line emission is observed across $\sim18\,$kpc scales with a resolution of $\sim 1\,\rm kpc$. About 78\% of the CO(1-0) luminosity traces a galaxy-size rotating disk. However, after subtracting the emission due to such rotating disk, we detect with a S/N=20 a residual emission in the central $\sim 4\,$kpc. Such residuals may trace a low velocity ($v_{LOS}=170\,\rm km\,s^{-1}$) outflow. We compare the momentum rate and kinetic power of such putative molecular outflow with that of the X-ray UFO and find $\dot{P}_{out}/\dot{P}_{UFO}=0.3\pm0.2$ and $\dot{E}_{mol}/\dot{E}_{UFO}\sim4\cdot10^{-3}$. This result is at odds with the energy-conserving scenario suggested by the large momentum boosts measured in some other molecular outflows. An alternative interpretation of the residual CO emission would be a compact rotating structure, distinct from the main disk, which would be a factor of $\sim10-100$ more extended and massive than typical circumnuclear disks revealed in Seyferts. However, in both scenarios, our results rule out the hypothesis of a momentum-boosted molecular outflow in this AGN, despite the presence of a powerful X-ray UFO. [Abridged]Comment: Accepted for publication in MNRAS. 13 pages, 11 figure

Policy recommendations: towards socially robust smart grids

This report presents the policy recommendations that follow from the EPINET projects investigations into assessments of ethical, legal and societal aspects of smart electricity grids in the European Union. Its main objective has been to evaluate the state-of-the-art in assessments in this domain, especially focusing on the ways in which these may interact with or become integrated into main research and innovation networks, including the making of research and policy agendas. These recommendations are aimed at, and relevant to, different groups and networks involved in smart electricity and governance at European and national levels. At one level of policy action there are the many advisory and expert groups involved in the design and development of smart grids. These include the EU Commission Task Force for Smart Grid. National initiatives such as the Dutch Smart Energy Collective form another target audience. Also relevant are the expert groups participating in the shaping of Horizon 2020 ICT programme (Societal Challenges and LEIT) and the European Institute of Innovation and Technology, national research councils and their advisory bodies. Our recommendations are especially relevant to so-called crosscutting actions in Horizon 2020, especially relating to Responsible Research and Innovation and Social and Humanistic Sciences. Next, our recommendations are also directed to national and EU legislators and regulators charged with adapting to and accommodating the actions of policy makers and the smart grid and smart cities communities. Finally, our recommendations are directed to the technology assessment community, including those dedicated to Responsible Research and Innovation, integrated ELSA and impact assessments

The effect of stellar feedback and quasar winds on the AGN population

In order to constrain the physical processes that regulate and downsize the AGN population, the predictions of the MOdel for the Rise of GAlaxies aNd Active nuclei (MORGANA) are compared to luminosity functions (LFs) of AGNs in the optical, soft X-ray and hard X-ray bands, to the local BH-bulge mass relation, and to the observed X-ray number counts and background. We also give predictions on the accretion rate of AGNs in units of the Eddington rate and on the BH--bulge relation expected at high redshift. We find that it is possible to reproduce the downsizing of AGNs within the hierarchical LambdaCDM cosmogony, and that the most likely responsible for this downsizing is the stellar kinetic feedback that arises in star-forming bulges as a consequence of the high level of turbulence and leads to a massive removal of cold gas in small elliptical galaxies. At the same time, to obtain good fits to the number of bright quasars we need to require that quasar-triggered galactic winds self-limit the accretion onto BHs. In all cases, the predicted BH--bulge relation steepens considerably with respect to the observed one at bulge masses <10^{11} Msun; this problem is related to a known excess in the predicted number of small bulges, common to most similar models, so that the reproduction of the correct number of faint AGNs is done at the cost of underestimating their BH masses. This highlights an insufficient downsizing of elliptical galaxies, and hints for another feedback mechanism able to act on the compact discs that form and soon merge at high redshift. The results of this paper reinforce the need for direct investigations of the feedback mechanisms in active galaxies, that will be possible with the next generation of astronomical telescopes from sub-mm to X-rays.Comment: 19 pages, 13 postscript figures included, uses mn2e.cls. Accepted by MNRA

Dramatic Changes in the Observed Velocity of the Accretion Disk Wind in MCG-03-58-007 Are Revealed by XMM-Newton and NuSTAR

Past X-ray observations of the nearby Seyfert 2 MCG-03-58-007 revealed the presence of a powerful and highly variable disk wind, where two possible phases outflowing with vout1/c ∼ −0.07 and vout2/c ∼ −0.2 were observed. Multi-epoch X-ray observations, covering the period from 2010 to 2018, showed that the lower-velocity component is persistent, as it was detected in all the observations, while the faster phase outflowing with vout2/c ∼ −0.2 appeared to be more sporadic. Here we present the analysis of a new monitoring campaign of MCG-03-58-007 performed in 2019 May–June and consisting of four simultaneous XMM-Newton and NuSTAR observations. We confirm that the disk wind in MCG-03-58-007 is persistent, as it is detected in all the observations, and powerful, having a kinetic power that ranges between 0.5% and 10% of the Eddington luminosity. The highly ionized wind (log(ξ/erg cm s−1) ∼ 5) is variable in both the opacity and, remarkably in its velocity. This is the first time where we have observed a substantial variability of the outflowing velocity in a disk wind, which dropped from vout/c ∼ −0.2 (as measured in the first three observations) to vout/c ∼ −0.074 in just 16 days. We conclude that such a dramatic and fast variability of the outflowing velocity could be due to the acceleration of the wind, as recently proposed by Mizumoto et al. Here, the faster wind, seen in the first three observations, is already accelerated to vout/c ∼ −0.2, while in the last observation our line of sight intercepts only the slower, pre-accelerated streamline