Mapping Seyfert and LINER Excitation Modes in the Inner kpc of NGC 3393

We have mapped the extended narrow line region (ENLR) of NGC 3393 on scales of $r\lesssim4^{\prime\prime}$ ($\sim1\,$kpc) from the nucleus using emission line images of H$\alpha\,\lambda6563$, [O III]$\lambda5007$, and [S II]$\lambda\lambda6717,6731$ taken with HST as part of the CHandra survey of Extended Emission line Regions in nearby Seyfert galaxies (CHEERS). By mapping these lines onto a spatially resolved Baldwin-Phillips-Terlevich (BPT) diagram, we investigate the impact of feedback from a Compton-thick AGN on its circumnuclear ISM. We find the expected Seyfert-like emission within the ionization bicone ($\lesssim3^{\prime\prime}$; 770 pc). We also find a new, figure 8 shaped LINER cocoon enveloping the bicone and defining a sharp ($\lesssim100\;$pc) transition between higher and lower ionization zones. These data illustrate the morphological dependence of ionization states of the ENLR relative to bicone and host gas geometries.Comment: Accepted by ApJ and published (2016, ApJ, 829, 46). Updated to reflect the accepted versio

Termination shocks and the extended X-ray emission in Mrk 78

Subarcsecond imaging of the X-ray emission in the type 2 active galactic nucleus (AGN) Mrk 78 with Chandra shows complex structure with spectral variations on scales from ∼200 pc to ∼2 kpc. Overall the X-ray emission is aligned E–W with the radio (3.6 cm) and narrow emission line region as mapped in [O III], with a marked E–W asymmetry. The eastern X-ray emission is mostly in a compact knot coincident with the location where the radio source is deflected, while the western X-ray emission forms a loop or shell ∼2 kpc from the nucleus with radius ∼0.7 kpc. There is suggestive evidence of shocks in both the eastern knot and the western arc. Both these positions coincide with large changes in the velocities of the [O III] outflow. We discuss possible reasons why the X-ray shocks on the western side occur ∼1 kpc farther out than on the eastern side. We estimate that the thermal energy injected by the shocks into the interstellar medium corresponds to 0.05%–0.6% of the AGN bolometric luminosity

Spatially resolved BPT mapping of nearby Seyfert 2 galaxies

We present spatially resolved BPT mapping of the extended narrow line regions (ENLRs) of seven nearby Seyfert 2 galaxies, using HST narrow band filter imaging. We construct the BPT diagrams using $\leq$ 0.1" resolution emission line images of [O III]$\lambda$5007, H$\alpha$, [S II]$\lambda$$\lambda$6717,6731, and H$\beta$. By mapping these diagnostic lines according to the BPT classification, we dissect the ENLR into Seyfert, LINER, and star-forming regions. The nucleus and ionization cones are dominated by Seyfert-type emission, which can be interpreted as predominantly photoionization by the active galactic nucleus (AGN). The Seyfert nucleus and ionization cones transition to and are surrounded by a LINER cocoon, extending up to $\sim$ 250 pc in thickness. The ubiquity of the LINER cocoon in Seyfert 2 galaxies suggests that the circumnuclear regions are not necessarily Seyfert-type, and LINER activity plays an important role in Seyfert 2 galaxies. We demonstrate that spatially resolved diagnostics are crucial to understanding the excitation mechanisms in different regions and the AGN-host galaxy interactions.Comment: 19 pages, 14 figures; accepted for publication in Ap

Mapping Seyfert and LINER excitation modes in the inner kpc of NGC 3393

We mapped the extended narrowline region (ENLR) of NGC 3393 on scales of r 4 (~1 kpc) from the nucleus using emission line images of Hα λ6563, [O III]l5007, and [S II]ll6717, 6731, taken with the Hubble Space Telescope as part of the CHandra survey of Extended Emission line Regions in nearby Seyfert galaxies (CHEERS). By mapping these lines onto a spatially resolved Baldwin–Phillips–Terlevich diagram, we investigate the impact of feedback from a Compton-thick active galactic nucleus on its circumnuclear ISM. We find that the expected Seyfert-like emission within the ionization bicone (3; 770 pc). We also find a new, figure-8-shaped low ionization emission line region (LINER) cocoon enveloping the bicone and defining a sharp (100 pc) transition between higher and lower-ionization zones. These data illustrate the morphological dependence of ionization states of the ENLR relative to bicone and host gas geometries

Epitaxy and magnetotransport of Sr_2FeMoO_6 thin films

By pulsed-laser deposition epitaxial thin films of Sr_2FeMoO_6 have been pre- pared on (100) SrTiO_3 substrates. Already for a deposition temperature of 320 C epitaxial growth is achieved. Depending on deposition parameters the films show metallic or semiconducting behavior. At high (low) deposition temperature the Fe,Mo sublattice has a rock-salt (random) structure. The metallic samples have a large negative magnetoresistance which peaks at the Curie temperature. The magnetic moment was determined to 4 mu_B per formula unit (f.u.), in agreement with the expected value for an ideal ferrimagnetic arrangement. We found an ordinary Hall coefficient of -6.01x10^{-10} m^3/As at 300 K, corresponding to an electronlike charge-carrier density of 1.3 per Fe,Mo-pair. In the semiconducting films the magnetic moment is reduced to 1 mu_B/f.u. due to disorder in the Fe,Mo sublattice. In low fields an anomalous holelike contribution dominates the Hall voltage, which vanishes at low temperatures for the metallic films only.Comment: Institute of Physics, University of Mainz, Germany, 4 pages, including 5 pictures and 1 Table, submitted to Phys. Rev.

Optical coherence tomography-guided versus angiography-guided implantation of everolimus-eluting bioresorbable vascular scaffolds: Comparison of coverage, apposition and clinical outcome. The ALSTER-OCT ABSORB registry

Background: Suboptimal implantation of everolimus-eluting bioresorbable vascular scaffolds (EE-BVS) leading to strut malapposition and lack of neointima coverage has been hypothesized to be linked to late BVS-thrombosis. Optical coherence tomography (OCT) allows assessing subtle differences in BVS-healing. We aimed to link 6-months OCT-data on EE-BVS coverage and malapposition to implantation technique and clinical outcome. Methods: Twenty-nine consecutive EE-BVS-patients were included. EE-BVS-implantation was guided by angiography in the first 17 patients (group 1). Vessel sizing prior to implantation and implantation result was assessed by OCT in the 12 following patients (group 2). EE-BVS-implantation was performed in both groups with adequate lesion preparation, sizing and systematic high-pressure post-dilatation. All patients received 6-months invasive control including OCT-analysis and clinical follow-up for 2 years. Results: The rate of uncovered struts was group 1: 10.8 ± 10.0%; group 2: 10.6 ± 8.2%, p = 0.934. Target lesion failure due to BVS-thrombosis occurred in 2/17 patients at 9 and 18 months (11.8%, group 1), and no patients in group 2 (p = 0.218). Conclusions: Optical coherence tomography analysis at 6-months following EE-BVS-implantation finds almost 90% of struts to be covered. No difference between OCT vs. angiography-guided EE-BVS-implantation was observed. OCT at 6-months was not able to predict late BVS-thrombosis of EE-BVS

Pictor A (PKS 0518-45) - From Nucleus to Lobes

We present radio and optical imaging and kinematic data for the radio galaxy Pictor A, including HST continuum and [OIII], emission-line images (at a resolution of 25 - 100 mas) and ground-based imaging and spectroscopy (at a resolution of ~ 1.5". The radio data include 3 cm Australia Telescope images of the core, at a resolution comparable to that of the optical, ground-based images, and a VLBI image of a jet in the compact core (at a resolution of 2 - 25 mas), which seems to align with a continuum ``jet'' found in the HST images. The core radio jet, the HST optical continuum ``jet'', and the NW H-alpha filaments all appear to point toward the optical-synchrotron hot-spot in the NW lobe of this object and are associated with a disrupted velocity field in the extended ionized gas. The ground-based spectra which cover this trajectory also yield line ratios for the ionized gas which have anomalously low [NII] (6564), suggesting either a complex, clumpy structure in the gas with a higher cloud-covering factor at larger radii and with denser clouds than is found in the nuclear regions of most NLRG and Seyfert 2 galaxies, or some other, unmodeled, mechanism for the emergent spectrum from this region. The H-alpha emission-line filaments to the N appear to be associated with a 3 cm radio continuum knot which lies in a gap in the filaments ~ 4" from the nucleus. Altogether, the data in this paper provide good circumstantial evidence for non-disruptive redirection of a radio jet by interstellar gas clouds in the host galaxy.Comment: 19 pages, 6 ps.gz fig pages, to appear in the Ap.J. Supp

ac-Field-Controlled Anderson Localization in Disordered Semiconductor Superlattices

An ac field, tuned exactly to resonance with the Stark ladder in an ideal tight binding lattice under strong dc bias, counteracts Wannier-Stark localization and leads to the emergence of extended Floquet states. If there is random disorder, these states localize. The localization lengths depend non-monotonically on the ac field amplitude and become essentially zero at certain parameters. This effect is of possible relevance for characterizing the quality of superlattice samples, and for performing experiments on Anderson localization in systems with well-defined disorder.Comment: 10 pages, Latex; figures available on request from [email protected]

Adiabatic population transfer via multiple intermediate states

This paper discusses a generalization of stimulated Raman adiabatic passage (STIRAP) in which the single intermediate state is replaced by $N$ intermediate states. Each of these states is connected to the initial state \state{i} with a coupling proportional to the pump pulse and to the final state \state{f} with a coupling proportional to the Stokes pulse, thus forming a parallel multi-$\Lambda$ system. It is shown that the dark (trapped) state exists only when the ratio between each pump coupling and the respective Stokes coupling is the same for all intermediate states. We derive the conditions for existence of a more general adiabatic-transfer state which includes transient contributions from the intermediate states but still transfers the population from state \state{i} to state \state{f} in the adiabatic limit. We present various numerical examples for success and failure of multi-$\Lambda$ STIRAP which illustrate the analytic predictions. Our results suggest that in the general case of arbitrary couplings, it is most appropriate to tune the pump and Stokes lasers either just below or just above all intermediate states.Comment: 14 pages, two-column revtex style, 10 figure

Spin-Orbit-Induced Magnetic Anisotropy for Impurities in Metallic Samples I. Surface Anisotropy

Motivated by the recent measurements of Kondo resistivity in thin films and wires, where the Kondo amplitude is suppressed for thinner samples, the surface anisotropy for magnetic impurities is studied. That anisotropy is developed in those cases where in addition to the exchange interaction with the impurity there is strong spin-orbit interaction for conduction electrons around the impurity in the ballistic region. The asymmetry in the neighborhood of the magnetic impurity exhibits the anisotropy axis $n$ which, in the case of a plane surface, is perpendicular to the surface. The anisotropy energy is $\Delta E=K_d (nS)^2$ for spin $S$, and the anisotropy constant $K_d$ is inversionally proportional to distance $d$ measured from the surface and $K_d>0$. Thus at low temperature the spin is frozen in a singlet or doublet of lowest energy. The influence of that anisotropy on the electrical resistivity is the subject of the following paper (part II).Comment: 28 pages, RevTeX (using epsfig), 8 eps figures included, submitted to PR