201 research outputs found

    Detection of extended millimeter emission in the host galaxy of 3C273 and its implications for QSO feedback via high dynamic range ALMA imaging

    Full text link
    We estimate the amount of negative feedback energy injected into the ISM of the host galaxy of 3C273, a prototypical radio loud quasar. We obtained 93, 233 and 343 GHz continuum images with the Atacama Large Millimeter/Sub-millimeter Array (ALMA). After self calibration and point source subtraction, we reach an image dynamic range of 85000\sim 85000 at 93\ GHz, 39000\sim 39000 at 233\ GHz and 2500\sim 2500 at 343\ GHz. These are currently the highest image dynamic range obtained using ALMA. We detect spatially extended millimeter emission associated with the host galaxy, cospatial with the Extended Emission Line Region (EELR) observed in the optical. The millimeter spectral energy distribution and comparison with centimeter data show that the extended emission cannot be explained by dust thermal emission, synchrotron or thermal bremsstrahlung arising from massive star formation. We interpret the extended millimeter emission as thermal bremsstrahlung from gas directly ionized by the central source. The extended flux indicates that at least 7%\sim 7\% of the bolometric flux of the nuclear source was used to ionize atomic hydrogen in the host galaxy. The ionized gas is estimated to be as massive as 101010^{10} to 1011 M10^{11}\ \mathrm{M_\odot}, but the molecular gas fraction with respect to the stellar mass is consistent with other ellipticals, suggesting that direct ionization ISM by the QSO may not be sufficient to suppress star formation, or we are witnessing a short timescale before negative feedback becomes observable. The discovery of a radio counterpart to EELRs provides a new pathway to studying the QSO-host ISM interaction

    Fluctuating Non-linear Non-equilibrium System in Terms of Nambu Thermodynamics

    Full text link
    It is shown that the structure of non-equilibrium thermodynamic system far from equilibrium can be captured in terms of a generalized "Nambu dynamics", in the presence of fluctuation effects in non-equilibrium thermodynamics. As concrete examples, chemical reaction systems with time oscillation, such as the Belousov-Zhabotinsky reaction (BZ reaction), are examined. The quantization of Nambu brackets arises naturally, which is expected to have applications in other regions such as fluid mechanics and string theory.Comment: 13 pages, 8 figure

    The Mean Absorption Line Spectra of a Selection of Luminous z~6 Lyman Break Galaxies

    Get PDF
    We examine the absorption line spectra of a sample of 31 luminous (M_UV=-23) Lyman break galaxies at redshift z~6 using data taken with the FOCAS and OSIRIS spectrographs on the Subaru and GTC telescopes. For two of these sources we present longer exposure data taken at higher spectral resolution from ESO's X-shooter spectrograph. Using these data, we demonstrate the practicality of stacking our lower resolution data to measure the depth of various interstellar and stellar absorption lines to probe the covering fraction of low ionization gas and the gas-phase and stellar metallicities near the end of the era of cosmic reionization. From maximum absorption line depths of SiII1260 and CII1334, we infer a mean covering fraction of >0.85+/-0.16 for our sample. This is larger than that determined using similar methods for lower luminosity galaxies at slightly lower redshifts, suggesting that the most luminous galaxies appear to have a lower escape fraction than fainter galaxies, and therefore may not play a prominent role in concluding reionization. Using various interstellar absorption lines we deduce gas-phase metallicities close to solar indicative of substantial early enrichment. Using selected stellar absorption lines, we model our spectra with a range of metallicities using techniques successfully employed at lower redshift and deduce a stellar metallicity of 0.4 +0.3/-0.1 solar, consistent with the stellar mass - stellar metallicity relation recently found at z~3-5. We discuss the implications of these metallicity estimates for the typical ages of our luminous galaxies and conclude our results imply initial star formation at redshifts z~10, consistent with independent analyses of earlier objects.Comment: 13 pages, 10 figures, 3 tables, Accepted for Publication in Ap

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

    Full text link
    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
    corecore