143 research outputs found

    Gait Coordination of Hexapod Walking Robots Using Mutual-Coupled Immune Networks

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    PROCEEDINGS OF THE IEEE INTERNATIONAL CONFERENCE ON EVOLUTIONARY COMPUTATIO

    The Complete Infrared View of Active Galactic Nuclei from the 70-month Swift/BAT Catalog

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    We systematically investigate the near- (NIR) to far-infrared (FIR) photometric properties of a nearly complete sample of local active galactic nuclei (AGN) detected in the Swift/Burst Alert Telescope (BAT) all-sky ultra hard X-ray (14-195 keV) survey. Out of 606 non-blazar AGN in the Swift/BAT 70-month catalog at high galactic latitude of b>10|b|>10^{\circ}, we obtain IR photometric data of 604 objects by cross-matching the AGN positions with catalogs from the WISE, AKARI, IRAS, and Herschel infrared observatories. We find a good correlation between the ultra-hard X-ray and mid-IR (MIR) luminosities over five orders of magnitude (41<log(L14195/erg s1)<4641 < \log (L_{14-195}/{\rm erg}~{\rm s}^{-1})< 46). Informed by previous measures of the intrinsic spectral energy distribution of AGN, we find FIR pure-AGN candidates whose FIR emission is thought to be AGN-dominated with low starformation activity. We demonstrate that the dust covering factor decreases with the bolometric AGN luminosity, confirming the luminosity-dependent unified scheme. We also show that the completeness of the WISE color-color cut in selecting Swift/BAT AGN increases strongly with 14-195 keV luminosity.Comment: 24 pages, 11 figures, accepted for publication in ApJ. The full list of Table 1 is available at http://www.kusastro.kyoto-u.ac.jp/~ichikawa/table1_MRT.tx

    A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). II. Physical Properties derived from the SED Fitting with Optical, Infrared, and Radio Data

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    We present physical properties of radio galaxies (RGs) with f1.4GHz>f_{\rm 1.4 GHz} > 1 mJy discovered by Subaru Hyper Supreme-Cam (HSC) and VLA Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey. For 1056 FIRST RGs at 0<z1.70 < z \leq 1.7 with HSC counterparts in about 100 deg2^2, we compiled multi-wavelength data of optical, near-infrared (IR), mid-IR, far-IR, and radio (150 MHz). We derived their color excess (E(BV)E (B-V)_{*}), stellar mass, star formation rate (SFR), IR luminosity, the ratio of IR and radio luminosity (qIRq_{\rm IR}), and radio spectral index (αradio\alpha_{\rm radio}) that are derived from the SED fitting with CIGALE. We also estimated Eddington ratio based on stellar mass and integration of the best-fit SEDs of AGN component. We found that E(BV)E (B-V)_{*}, SFR, and IR luminosity clearly depend on redshift while stellar mass, qIRq_{\rm IR}, and αradio\alpha_{\rm radio} do not significantly depend on redshift. Since optically-faint (iAB21.3i_{\rm AB} \geq 21.3) RGs that are newly discovered by our RG survey tend to be high redshift, they tend to not only have a large dust extinction and low stellar mass but also have high SFR and AGN luminosity, high IR luminosity, and high Eddington ratio compared to optically-bright ones. The physical properties of a fraction of RGs in our sample seem to differ from a classical view of RGs with massive stellar mass, low SFR, and low Eddington ratio, demonstrating that our RG survey with HSC and FIRST provides us curious RGs among entire RG population.Comment: 30 pages, 20 figures, and 4 tables, accepted for publication in ApJS. The catalog and SED template of radio galaxies will be accessible through an online servic

    Discovery of Dying Active Galactic Nucleus in Arp 187: Experience of Drastic Luminosity Decline within 10410^4 years

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    Arp 187 is one of the fading active galactic nuclei (AGN), whose AGN activity is currently decreasing in luminosity. We investigate the observational signatures of AGN in Arp 187, which trace various physical scales from less than 0.1 pc to the nearly 10 kpc, to estimate the longterm luminosity change over 10410^{4} years. The VLA 5 GHz, 8 GHz, and the ALMA 133 GHz images reveal bimodal jet lobes with \sim5 kpc size and the absence of the central radio-core. The 6dF optical spectrum shows that Arp 187 hosts narrow line region with the estimated size of \sim1 kpc, and the line strengths give the AGN luminosity of Lbol=1.5×1046L_{\rm bol}=1.5 \times 10^{46} erg s1^{-1}. On the other hand, the current AGN activity estimated from the AGN torus emission gives the upper bound of Lbol<2.2×1043L_{\rm bol} < 2.2 \times 10^{43} erg s1^{-1}. The absence of the radio-core gives the more strict upper bound of the current AGN luminosity of Lbol<8.0×1040L_{\rm bol} < 8.0 \times 10^{40} erg s1^{-1}, suggesting that the central engine is already quenched. These multi-wavelength signatures indicate that Arp 187 hosts a "dying" AGN: the central engine is already dead, but the large scale AGN indicators are still observable as the remnant of the past AGN activity. The central engine has experienced the drastic luminosity decline by a factor of 1035\sim10^{3-5} fainter within 104\sim10^{4} years, which is roughly consistent with the viscous timescale of the inner part of the accretion disk within \sim500 years.Comment: 15 pages, 8 figures, accepted for publication in Ap
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