1,504 research outputs found

    [O III]λ5007\lambda 5007 and X-ray Properties of a Complete Sample of Hard X-ray Selected AGNs in the Local Universe

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    We study the correlation between the [O III]λ5007\lambda 5007 and X-ray luminosities of local Active Galactic Nuclei (AGNs), using a complete, hard X-ray (>10>10 keV) selected sample in the Swift/BAT 9-month catalog. From our optical spectroscopic observations at the South African Astronomical Observatory and the literature, a catalog of [O III]λ5007\lambda 5007 line flux for all 103 AGNs at Galactic latitudes of b>15|b|>15^\circ is complied. Significant correlations with intrinsic X-ray luminosity (LXL_{\rm X}) are found both for observed (L[O III]L_{\rm [O~III]}) and extinction-corrected (L[O III]corL_{\rm [O~III]}^{\rm cor}) luminosities, separately for X-ray unabsorbed and absorbed AGNs. We obtain the regression form of L[O III]L_{\rm [O~III]} L210  keV1.18±0.07\propto L_{\rm 2-10\; keV}^{1.18\pm0.07} and L[O III]corL_{\rm [O~III]}^{\rm cor} L210  keV1.16±0.09\propto L_{\rm 2-10\; keV}^{1.16\pm0.09} from the whole sample. The absorbed AGNs with low (<<0.5\%) scattering fractions in soft X-rays show on average smaller L[O III]/LXL_{\rm [O~III]}/L_{\rm X} and L[O III]cor/LXL_{\rm [O~III]}^{\rm cor}/L_{\rm X} ratios than the other absorbed AGNs, while those in edge-on host galaxies do not. These results suggest that a significant fraction of this population are buried in tori with small opening angles. By using these L[O III]L_{\rm [O~III]} vs. LXL_{\rm X} correlations, the X-ray luminosity function of local AGNs (including Compton thick AGNs) in a standard population synthesis model gives much better agreement with the [O III]λ5007\lambda 5007 luminosity function derived from the Sloan Digital Sky Survey than previously reported. This confirms that hard X-ray observations are a very powerful tool to find AGNs with high completeness.Comment: 14 pages including 11 figures and 3 tables, accepted for publication in ApJ. In this manuscript, the observed 14-195 keV luminosities in Table 1 have been corrected to be exactly the same as in the original Swift/BAT 9-month catalog. Accordingly, Figures 2(a) and 3(a) and a part of Tables 2 and 3 have been updated. The changes from the previous version are small and do not affect the tex

    The relationship between adverse childhood experiences, coping using sex, and adult sexual coercion in non-incarcerated, community-based females

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    Adverse childhood experiences have been associated with negative outcomes in adulthood, including sexual offending. Using a cross-sectional design, we investigated whether self-reported adverse childhood experiences related to the perpetration of coercive sexual acts among 250 females recruited from the community. Furthermore, we examined whether sexualised coping mediated any potential relationship between childhood experiences and sexual coercion. A Spearman’s rank order correlation revealed no relationship between adverse childhood experiences and sexual coercion. However, adverse childhood experiences were significantly correlated with sexualised coping, which in turn was correlated with sexual coercion. Additionally, there was a significant but small indirect effect of adverse childhood experiences on sexual coercion through sexualised coping. Findings may help researchers to better understand the causal relationship between childhood experiences, sexual coping, and sexual coercion in females

    Investigating the evolution of the dual AGN system ESO~509-IG066

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    We analyze the evolution of the dual AGN in ESO 509-IG066, a galaxy pair located at z=0.034 whose nuclei are separated by 11 kpc. Previous observations with XMM-Newton on this dual AGN found evidence for two moderately obscured (NH1022N_H\sim10^{22} cm2^{-2}) X-ray luminous (LX1043L_X\sim10^{43} erg/s) nuclear sources. We present an analysis of subsequent Chandra, NuSTAR and Swift/XRT observations that show one source has dropped in flux by a factor of 10 between 2004 and 2011, which could be explained by either an increase in the absorbing column or an intrinsic fading of the central engine possibly due to a decrease in mass accretion. Both of these scenarios are predicted by galaxy merger simulations. The source which has dropped in flux is not detected by NuSTAR, which argues against absorption, unless it is extreme. However, new Keck/LRIS optical spectroscopy reveals a previously unreported broad H-alpha line which is highly unlikely to be visible under the extreme absorption scenario. We therefore conclude that the black hole in this nucleus has undergone a dramatic drop in accretion rate. From AO-assisted near-infrared integral-field spectroscopy of the other nucleus, we find evidence that the galaxy merger is having a direct effect on the kinematics of the gas close to the nucleus of the galaxy, providing a direct observational link between the galaxy merger and the mass accretion rate on to the black hole.Comment: Accepted for publication in Ap

    X-ray bolometric corrections for Compton-thick active galactic nuclei

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    We present X-ray bolometric correction factors, κBol\kappa_{Bol} (LBol/LX\equiv L_{Bol}/L_X), for Compton-thick (CT) active galactic nuclei (AGN) with the aim of testing AGN torus models, probing orientation effects, and estimating the bolometric output of the most obscured AGN. We adopt bolometric luminosities, LBolL_{Bol}, from literature infrared (IR) torus modeling and compile published intrinsic 2--10 keV X-ray luminosities, LXL_{X}, from X-ray torus modeling of NuSTAR data. Our sample consists of 10 local CT AGN where both of these estimates are available. We test for systematic differences in κBol\kappa_{Bol} values produced when using two widely used IR torus models and two widely used X-ray torus models, finding consistency within the uncertainties. We find that the mean κBol\kappa_{Bol} of our sample in the range LBol10421045L_{Bol}\approx10^{42}-10^{45} erg/s is log10κBol=1.44±0.12_{10}\kappa_{Bol}=1.44\pm0.12 with an intrinsic scatter of 0.2\sim0.2 dex, and that our derived κBol\kappa_{Bol} values are consistent with previously established relationships between κBol\kappa_{Bol} and LBolL_{Bol} and κBol\kappa_{Bol} and Eddington ratio. We investigate if κBol\kappa_{Bol} is dependent on NHN_H by comparing our results on CT AGN to published results on less-obscured AGN, finding no significant dependence. Since many of our sample are megamaser AGN, known to be viewed edge-on, and furthermore under the assumptions of AGN unification whereby unobscured AGN are viewed face-on, our result implies that the X-ray emitting corona is not strongly anisotropic. Finally, we present κBol\kappa_{Bol} values for CT AGN identified in X-ray surveys as a function of their observed LXL_X, where an estimate of their intrinsic LXL_{X} is not available, and redshift, useful for estimating the bolometric output of the most obscured AGN across cosmic time.Comment: Accepted for publication in Ap

    Interactional positioning and narrative self-construction in the first session of psychodynamic-interpersonal psychotherapy

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    The purpose of this study is to identify possible session one indicators of end of treatment psychotherapy outcome using the framework of three types of interactional positioning; client’s self-positioning, client’s positioning between narrated self and different partners, and the positioning between client and therapist. Three successful cases of 8-session psychodynamic-interpersonal (PI) therapy were selected on the basis of client Beck Depression Inventory scores. One unsuccessful case was also selected against which identified patterns could be tested. The successful clients were more descriptive about their problems and demonstrated active rapport-building, while the therapist used positionings expressed by the client in order to explore the positionings developed between them during therapy. The unsuccessful case was characterized by lack of positive self-comment, minimization of agentic self-capacity, and empathy-disrupting narrative confusions. We conclude that the theory of interactional positioning has been useful in identifying patterns worth exploring as early indicators of success in PI therapy

    IC 751: a new changing-look AGN discovered by NuSTAR

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    We present the results of five NuSTAR observations of the type 2 active galactic nucleus (AGN) in IC 751, three of which were performed simultaneously with XMM-Newton or Swift/XRT. We find that the nuclear X-ray source underwent a clear transition from a Compton-thick (NH2×1024cm2N_{\rm\,H}\simeq 2\times 10^{24}\rm\,cm^{-2}) to a Compton-thin (NH4×1023cm2N_{\rm\,H}\simeq 4\times 10^{23}\rm\,cm^{-2}) state on timescales of 3\lesssim 3 months, which makes IC 751 the first changing-look AGN discovered by NuSTAR. Changes of the line-of-sight column density at a 2σ\sim2\sigma level are also found on a time-scale of 48\sim 48 hours (ΔNH1023cm2\Delta N_{\rm\,H}\sim 10^{23}\rm\,cm^{-2}). From the lack of spectral variability on timescales of 100\sim 100 ks we infer that the varying absorber is located beyond the emission-weighted average radius of the broad-line region, and could therefore be related either to the external part of the broad-line region or a clumpy molecular torus. By adopting a physical torus X-ray spectral model, we are able to disentangle the column density of the non-varying absorber (NH3.8×1023cm2N_{\rm\,H}\sim 3.8\times 10^{23}\rm\,cm^{-2}) from that of the varying clouds [NH(1150)×1022cm2N_{\rm\,H}\sim(1-150)\times10^{22}\rm\,cm^{-2}], and to constrain that of the material responsible for the reprocessed X-ray radiation (NH6×1024cm2N_{\rm\,H} \sim 6 \times 10^{24}\rm\,cm^{-2}). We find evidence of significant intrinsic X-ray variability, with the flux varying by a factor of five on timescales of a few months in the 2-10 and 10-50 keV band.Comment: Accepted for publication in ApJ, 11 pages, 6 figure

    Broadband Observations of the Compton-thick Nucleus of NGC 3393

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    We present new NuSTAR and Chandra observations of NGC 3393, a galaxy reported to host the smallest separation dual AGN resolved in the X-rays. While past results suggested a 150 pc separation dual AGN, three times deeper Chandra imaging, combined with adaptive optics and radio imaging suggest a single, heavily obscured, radio-bright AGN. Using VLA and VLBA data, we find an AGN with a two-sided jet rather than a dual AGN and that the hard X-ray, UV, optical, NIR, and radio emission are all from a single point source with a radius <0.2". We find that the previously reported dual AGN is most likely a spurious detection resulting from the low number of X-ray counts (<160) at 6-7 keV and Gaussian smoothing of the data on scales much smaller than the PSF (0.25" vs. 0.80" FWHM). We show that statistical noise in a single Chandra PSF generates spurious dual peaks of the same separation (0.55±\pm0.07" vs. 0.6") and flux ratio (39±\pm9% vs. 32% of counts) as the purported dual AGN. With NuSTAR, we measure a Compton-thick source (NH=2.2±0.4×10242.2\pm0.4\times10^{24} cm2^{-2}) with a large torus half-opening angle, {\theta}=79 which we postulate results from feedback from strong radio jets. This AGN shows a 2-10 keV intrinsic to observed flux ratio of 150. Using simulations, we find that even the deepest Chandra observations would severely underestimate the intrinsic luminosity of NGC 3393 above z>0.2, but would detect an unobscured AGN of this luminosity out to high redshift (z=5).Comment: Accepted for publication in ApJ. 15 Figures and 4 table

    Broadband X-ray spectral analysis of the Seyfert 1 galaxy GRS 1734-292

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    We discuss the broadband X-ray spectrum of GRS 1734-292 obtained from non-simultaneous XMM-Newton and NuSTAR observations, performed in 2009 and 2014, respectively. GRS1734-292 is a Seyfert 1 galaxy, located near the Galactic plane at z=0.0214z=0.0214. The NuSTAR spectrum (3803-80 keV) is dominated by a primary power-law continuum with Γ=1.65±0.05\Gamma=1.65 \pm 0.05 and a high-energy cutoff Ec=538+11E_c=53^{+11}_{-8} keV, one of the lowest measured by NuSTAR in a Seyfert galaxy. Comptonization models show a temperature of the coronal plasma of kTe=11.90.9+1.2kT_e=11.9^{+1.2}_{-0.9} keV and an optical depth, assuming a slab geometry, τ=2.980.19+0.16\tau=2.98^{+0.16}_{-0.19} or a similar temperature and τ=6.70.4+0.3\tau=6.7^{+0.3}_{-0.4} assuming a spherical geometry. The 2009 XMM-Newton spectrum is well described by a flatter intrinsic continuum (Γ=1.470.03+0.07\Gamma=1.47^{+0.07}_{-0.03}) and one absorption line due to Fe\textsc{XXV} Kα\alpha produced by a warm absorber. Both data sets show a modest iron Kα\alpha emission line at 6.46.4 keV and the associated Compton reflection, due to reprocessing from neutral circumnuclear material

    X-Ray, UV, and Optical Observations of Supernova 2006bp with Swift: Detection of Early X-Ray Emission

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    We present results on the X-ray and optical/UV emission from the type IIP SN 2006bp and the interaction of the SN shock with its environment, obtained with the X-Ray Telescope (XRT) and UV/Optical Telescope (UVOT) on-board the Swift observatory. SN 2006bp is detected in X-rays at a 4.5 sigma level of significance in the merged XRT data from days 1 to 12 after the explosion. If the X-ray luminosity of (1.8+/-0.4)E39 ergs/s is caused by interaction of the SN shock with circumstellar material (CSM), deposited by a stellar wind from the progenitor's companion star, a mass-loss rate of ~E-05 M_sun/yr is inferred. The mass-loss rate is consistent with the non-detection in the radio with the VLA on days 2, 9, and 11 after the explosion and characteristic of a red supergiant progenitor with a mass around 12-15 M_sun prior to the explosion. In combination with a follow-up XMM-Newton observation obtained on day 21 after the explosion, an X-ray rate of decline with index 1.2+/-0.6 is inferred. Since no other SN has been detected in X-rays prior to the optical peak and since type IIP SNe have an extended 'plateau' phase in the optical, we discuss the scenario that the X-rays might be due to inverse Compton scattering of photospheric optical photons off relativistic electrons produced in circumstellar shocks. However, due to the high required value of the Lorentz factor (~10-100) we conclude that Inverse Compton scattering is an unlikely explanation for the observed X-ray emission. The fast evolution of the optical/ultraviolet spectral energy distribution and the spectral changes observed with Swift reveal the onset of metal line-blanketing and cooling of the expanding photosphere during the first few weeks after the outburst.Comment: 8 pages, 5 figures, accepted for publication in Ap
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