2,143 research outputs found

    Optical and X-ray Properties of the Swift BAT-detected AGN

    Full text link
    The Swift Gamma-Ray Burst satellite has detected a largely unbiased towards absorption sample of local (≈0.03 \approx 0.03) AGN, based solely on their 14--195 keV flux. In the first 9 months of the survey, 153 AGN sources were detected. The X-ray properties in the 0.3--10 keV band have been compiled and presented based on analyses with XMM-Newton, Chandra, Suzaku, and the Swift XRT (Winter et al. 2009). Additionally, we have compiled a sub-sample of sources with medium resolution optical ground-based spectra from the SDSS or our own observations at KPNO. In this sample of 60 sources, we have classified the sources using standard emission line diagnostic plots, obtained masses for the broad line sources through measurement of the broad HÎČ\beta emission line, and measured the [OIII] 5007\AA luminosity of this sample. Based on continuum fits to the intrinsic absorption features, we have obtained clues about the stellar populations of the host galaxies. We now present the highlights of our X-ray and optical studies of this unique sample of local AGNs, including a comparison of the 2--10 keV and 14--195 keV X-ray luminosities with the [OIII] 5007\AA luminosity and the implications of our results towards measurements of bolometric luminosities.Comment: 4 pages, 2 figures, to appear in proceedings for 'X-ray Astronomy 2009', Bologna 09/2009, AIP Conference Series, Eds. A. Comastri, M. Cappi, L. Angelin

    HASH(0x563d440dcea0)

    Get PDF
    HASH(0x563d4407a270)HASH(0x563d4412f6b0

    Design and Development of the Clementine Spacecraft Sensor Bench

    Get PDF
    The Clementine spacecraft was developed to demonstrate the performance of BMDO\u27s lightweight sensor suite. The suite consisted of five different sensors (Star Trackers, UV/Vis, HiRes, NIR, LWIR) and a UDAR (Laser Impulse Detection And Ranging) system. The worst-case sensor operating requirements for the Clementine mission were: interface temperature with -20 to 2° C, alignment to +/- 100”Rad, and jitter kept below 40 Rad in 40msec. The average hear dissipation of the suite was over 100 Watts while operating for two of the five hour lunar orbit. To accomplish the mission the sensor suite was integrated onto a single-substrate sensor bench within the spacecraft. The bench met the stringent thermal, alignment, and jitter requirements of the sensors, and concurrently isolated the sensors from outside spacecraft contamination, as well as thermal and structural flexure. Also taken into account were the mission design drivers of hot thermal environment in lunar orbit, limited volume in the spacecraft, minimal weight, limited budget, and a six month schedule from concept to delivery of a flight bench. The design and development of the sensor bench will be discussed. Three different types of heat pipes were used to transport the heat of the sensors to radiators located on the side of the spacecraft. A beryllium metal block was used as a thermal capacitor during peak heat loads. Thermal straps connected sensors to heat pipes to keep thermal gradients as little as 3° C per inch across the interface. The bench was fastened in a quasi-kinematic fashion to eliminate the transfer of spacecraft structural loads and thermal flexing, and yet was rigid enough to keep alignment through launch. The bench substrate itself was made out of aluminum honeycomb. The alignment mechanism consisted of a nut-on-nut method to attain and keep the 100”Rad requirement. Volume and alignment constraints dictated sensor location on the bench. Development of the bench involved rigorous testing to insure requirements were met. These tests involved development alignment checks, vibration testing at the sensor bench level, system level qual vibes and TDVT, system level jitter testing, as well as the flight system vibe, TV AC and functional. Lessons learned will be discussed

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

    Full text link
    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]} ∝L2−10  keV1.18±0.07\propto L_{\rm 2-10\; keV}^{1.18\pm0.07} and L[O III]corL_{\rm [O~III]}^{\rm cor} ∝L2−10  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

    A Hard Look at NGC 5347: Revealing a Nearby Compton-thick AGN

    Get PDF
    Current measurements show that the observed fraction of Compton-thick (CT) active galactic nuclei (AGN) is smaller than the expected values needed to explain the cosmic X-ray background. Prior fits to the X-ray spectrum of the nearby Seyfert-2 galaxy NGC 5347 (z = 0.00792, D = 35.5 Mpc ) have alternately suggested a CT and Compton-thin source. Combining archival data from Suzaku, Chandra, and—most importantly—new data from NuSTAR, ... See full text for complete abstrac

    XMM Follow-Up Observations of Three Swift BAT-Selected Active Galactic Nuclei

    Full text link
    We present XMM-Newton observations of three AGN taken as part of a hunt to find very heavily obscured Compton-thick AGN. For obscuring columns greater than 10^25 cm^-2, AGN are only visible at energies below 10 keV via reflected/scattered radiation, characterized by a flat power-law. We therefore selected three objects (ESO 417-G006, IRAS 05218-1212, and MCG -01-05-047) from the Swift BAT hard X-ray survey catalog with Swift X-ray Telescope XRT 0.5-10 keV spectra with flat power-law indices as candidate Compton-thick sources for follow-up observations with the more sensitive instruments on XMM-Newton. The XMM spectra, however, rule out reflection-dominated models based on the weakness of the observed Fe K-alpha lines. Instead, the spectra are well-fit by a model of a power-law continuum obscured by a Compton-thin absorber, plus a soft excess. This result is consistent with previous follow-up observations of two other flat-spectrum BAT-detected AGN. Thus, out of the six AGN in the 22-month BAT catalog with apparently flat Swift XRT spectra, all five that have had follow-up observations are not likely Compton-thick. We also present new optical spectra of two of these objects, IRAS 05218-1212 and MCG -01-05-047. Interestingly, though both these AGN have similar X-ray spectra, their optical spectra are completely different, adding evidence against the simplest form of the geometric unified model of AGN. IRAS 05218-1212 appears in the optical as a Seyfert 1, despite the ~8.5x10^22 cm^-2 line-of-sight absorbing column indicated by its X-ray spectrum. MCG -01-05-047's optical spectrum shows no sign of AGN activity; it appears as a normal galaxy.Comment: 18 pages including 4 figures, accepted by Ap

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

    Get PDF
    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
    • 

    corecore