On the presence of ultra-fast outflows in the WAX sample of Seyfert galaxies

The study of winds in active galactic nuclei (AGN) is of utmost importance as they may provide the long sought-after link between the central black hole and the host galaxy, establishing the AGN feedback. Recently, Laha et al. (2014) reported the X-ray analysis of a sample of 26 Seyferts observed with XMM-Newton, which are part of the so-called warm absorbers in X-rays (WAX) sample. They claim the non-detection of Fe K absorbers indicative of ultra-fast outflows (UFOs) in four observations previously analyzed by Tombesi et al. (2010). They mainly impute the Tombesi et al. detections to an improper modeling of the underlying continuum in the E=4-10 keV band. We therefore re-address here the robustness of these detections and we find that the main reason for the claimed non-detections is likely due to their use of single events only spectra, which reduces the total counts by 40%. Performing a re-analysis of the data in the whole E=0.3-10 keV energy band using their models and spectra including also double events, we find that the blue-shifted Fe K absorption lines are indeed detected at >99%. This work demonstrates the robustness of these detections in XMM-Newton even including complex model components such as reflection, relativistic lines and warm absorbers.Comment: 5 pages, 1 figure, accepted for publication in MNRA

Multiturn Extraction: Performance Analysis of Old and New Approaches

Super Proton Synchrotron. The present approach is based on beam slicing via an electrostatic septum. However, recently a novel technique was proposed. By using nonlinear magnetic elements, stable islands can be generated in the transverse phase space. Furthermore, if the linear tune is varied slowly, it is possible to trap the charged particles inside the stable islands so that the beam is split into different beamlets ready for extraction. In this paper, both techniques are discussed in details with special emphasis on their robustness and the phase space matching of the extracted beam

Novel Method for Multi-turn Extraction: trapping charged Particles in Islands of Phase Space

A novel method for multi-turn extraction from a circular particle accelerator is presented. It is based on trapping particles into islands of phase space generated by nonlinear resonances. By appropriate use of nonlinear elements (sextupoles, octupoles), stable islands can be created at small amplitude in phase space. By varying the linear tune, it is shown how particles can be trapped inside these islands. The particles can then be coherently transported towards higher amplitudes for extraction. Results of numerical simulations are presented and discussed in detail

Computation of betatron mismatch and emmitance blow-up for multi-turn extraction

The present version of the five-turn Continuous Transfer extraction at PS machine is based on beam slicing by means of an electrostatic septum. Recently, a novel approach has been proposed, where the beam is split into five beamlets by means of stable islands, created by sextupoles and octupoles, together with a proper tune variation. In this paper, the two approaches are compared by considering their properties in terms of equivalent optical parameters, beam emittance, and emittance after filamentation in the receiving machine (SPS) for the various slices. Analytic expressions of the relevant optical and beam parameters are derived for the present version of the Continuous Transfer, while the same quantities are estimated in the case of the novel approach via numerical simulations. Finally, the robustness of the approach based on adiabatic capture in transverse phase space is discussed with particular emphasis on tune ripple effects and variation of nonlinear elements strength

The Proton Beams for the New Time-of-Flight Neutron Facility at the CERN-PS

The experimental determination of neutron cross sections in fission and capture reactions as a function of the neutron energy is of primary importance in nuclear physics. Recent developments at CERN and elsewhere have shown that many fields of research and development, such as the design of Accelerator-Driven Systems (ADS) for nuclear waste incineration, nuclear astrophysics, fundamental nuclear physics, dosimetry for radiological protection and therapy, would benefit from a better knowledge of neutron cross sections. A neutron facility at the CERN-PS has been proposed with the aim of carrying out a systematic and high resolution study of neutron cross sections through Time-Of-Flight (n-TOF) measurement. The facility requires a high intensity proton beam (about 0.7x1013 particles/bunch) distributed in a short bunch (about 25 ns total length) to produce the neutrons by means of a spallation process in a lead target. To achieve these characteristics, a number of complex beam gymnastics have to be performed. All the beam manipulations are presented in this paper as well as some beam dynamics issues encountered during the setting up. The details of the new transfer line used to deliver the beam onto the target are also described

Outflows, Feedback and SMBH/Galaxy Co-Evolution

After a brief introduction on the current state-of-the-art for studies of outflows, feedback and SMBG/Galaxy co-evolution, I will address some of the future prospects in this field

On the relativistic iron line and soft excess in the Seyfert 1 galaxy Markarian 335

We report on a 133 ks XMM-Newton observation of the Seyfert 1 galaxy Markarian 335. The 0.4-12 keV spectrum contains an underlying power law continuum, a soft excess below 2 keV, and a double-peaked iron emission feature in the 6-7 keV range. We investigate the possibility that the double-peaked emission might represent the characteristic signature of the accretion disc. Detailed investigations show that a moderately broad, accretion disc line is most likely present, but that the peaks may be owing to narrower components from more distant material. The peaks at 6.4 and 7 keV can be identified, respectively, with the molecular torus in active galactic nucleus unification schemes, and very highly ionized, optically thin gas filling the torus. The X-ray variability spectra on both long (~100 ks) and short (~1 ks) timescales disfavour the recent suggestion that the soft excess is an artifact of variable, moderately ionized absorption.Comment: 6 pages, 2 figures, accepted for publication in MNRA

Evidence for relativistic features in the X-ray spectrum of Mrk 335

We present an analysis of hard X-ray features in the spectrum of the bright Sy 1 galaxy Mrk 335 observed by the XMM-Newton satellite. Our analysis confi rms the presence of a broad, ionised iron Kalpha emission line in the spectrum, first found by Gondoin et al. The broad line can be modeled successfully by relativistic accretion disc reflection models. This interpretation is unusually robust in the case of Mrk 335 because of the lack of any ionised (`` warm'') absorber and the absence a clear narrow core to the line. Partial covering by neutral gas cannot, however, be ruled out statistically as the origin of the broad residuals. Regardless of the underlyin g continuum we report, for the first time in this source, the detection of a narrow absorption feature at the rest frame energy of ~5.9 keV. If the feature is identified with a resonance absorption line of iron in a highly ionised medium, the redshift of the line corresponds to an inflow velocity of ~0.11 -0.15 c. We present a simple model for the inflow, accounting approximate ly for relativistic and radiation pressure effects, and use Monte Carlo methods to compute synthetic spectra for qualitative comparison with the data. This mode ling shows that the absorption feature can plausibly be reproduced by infalling gas providing that the feature is identified with Fe xxvi. We require the inflowing gas to extend over a limited range of radii at a few tens of rg to match the observed feature. The mass accretion rate in the flow correspond s to 60% of the Eddington limit, in remarkable agreement with the observed rate . The narrowness of the absorption line tends to argue against a purely gravitational origin for the redshift of the line, but given the current data quality we stress that such an interpretation cannot be ruled out.Comment: 12 pages, 9 figures, accepted for publication on MNRAS, including referee's comment