1,893 research outputs found

    Detection of Far Infrared Emission from Galaxies and Quasars in the Galactic Extinction Map by Stacking Analysis

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    We have performed stacking image analyses of galaxies over the Galactic extinction map constructed by Schlegel, Finkbeiner & Davis (1998). We select ~10^7 galaxies in total from the Sloan Digital Sky Survey (SDSS) DR7 photometric catalog. We detect clear signatures of the enhancement of the extinction in r-band, ΔAr\Delta A_r, around galaxies, indicating that the extinction map is contaminated by their FIR (far infrared) emission. The average amplitude of the contamination per galaxy is well fitted to ΔAr(mr)=0.64×100.17(18mr)\Delta A_r(m_r) = 0.64 \times 10^{0.17(18-m_r)} [mmag]. While this value is very small, it is directly associated with galaxies and may have a systematic effect on galaxy statistics. Indeed this correlated contamination leads to a relatively large anomaly of galaxy surface number densities against the SFD extinction A_SFD discovered by Yahata et al. (2007). We model the radial profiles of stacked galaxy images, and find that the FIR signal around each galaxy does not originate from the central galaxy alone, but is dominated by the contributions of nearby galaxies via galaxy angular clustering. The separation of the single galaxy and the clustering terms enables us to infer the statistical relation of the FIR and r-band fluxes of galaxies and also to probe the flux-weighted cross-correlation of galaxies, down to the magnitudes that are difficult to probe directly for individual objects. We repeat the same stacking analysis for SDSS DR6 photometric quasars and discovered the similar signatures but with weaker amplitudes. The implications of the present results for galaxy and quasar statistics and for correction to the Galactic extinction map are briefly discussed.Comment: 11 pages, 19 figures, PASJ, 2013, vol65, No.3, in pres

    The Unusual Spectral Energy Distribution of a Galaxy Previously Reported to be at Redshift 6.68

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    Observations of distant galaxies are important both for understanding how galaxies form and for probing the physical conditions of the universe at the earliest epochs. It is, however, extremely difficult to identify galaxies at redshift z>5, because these galaxies are faint and exhibit few spectral features. In a previous work, we presented observations that supported the identification of a galaxy at redshift z = 6.68 in a deep STIS field. Here we present new ground-based photometry of the galaxy. We find that the galaxy exhibits moderate detections of flux in the optical B and V images that are inconsistent with the expected absence of flux at wavelength shortward of the redshifted Lyman-alpha emission line of a galaxy at redshift z>5. In addition, the new broad-band imaging data not only show flux measurements of this galaxy that are incompatible with the previous STIS measurement, but also suggest a peculiar spectral energy distribution that cannot be fit with any galaxy spectral template at any redshift. We therefore conclude that the redshift identification of this galaxy remains undetermined.Comment: 9 pages, 2 figures; To appear in Nature (30 November 2000

    A New Aglaonema Foliar Blight and Crown Rot

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    The cause of leaf, petiole, collar, and cane rots of aglaonema in Hawaii was determined to be Fusarium subglutinans. A bacterial leaf rot was also investigated. Disease management advice is given

    Flowering and Fruiting Haploid and Doubled Haploid Pummelos

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    Haploid and doubled haploid (DH) plants are of great value for genetic analyses and premeditated breeding. This is especially true for woody species, which are generally characterized by a long reproductive cycle, a high degree of heterozygosity, a large plant size, and self-incompatibility. In Citrus and related genera, some haploid and DH plants have been produced by techniques such as anther culture, interploid hybridization, and the pollination of irradiated pollen. However, there are few reports of the characteristics of haploid and DH plants’ flowers, fruits, or reproductive potential. We selected a haploid progeny among small seed-derived seedlings obtained from ‘Banpeiyu’ pummelo [C. maxima (Burm.) Merr.], and we produced the DH plant of this haploid using colchicine-treated axillary shoot buds. Both this haploid pummelo and the DH pummelo showed normal growth and produced many flowers and fruit. In this chapter, we describe about the morphological characteristics and the reproductive potential of the haploid pummelo and the DH pummelo

    A dipole anisotropy of galaxy distribution: Does the CMB rest-frame exist in the local universe?

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    The peculiar motion of the Earth causes a dipole anisotropy modulation in the distant galaxy distribution due to the aberration effect. However, the amplitude and angular direction of the effect is not necessarily the same as those of the cosmic microwave background (CMB) dipole anisotropy due to the growth of cosmic structures. In other words exploring the aberration effect may give us a clue to the horizon-scale physics perhaps related to the cosmic acceleration. In this paper we develop a method to explore the dipole angular modulation from the pixelized galaxy data on the sky properly taking into account the covariances due to the shot noise and the intrinsic galaxy clustering contamination as well as the partial sky coverage. We applied the method to the galaxy catalogs constructed from the Sloan Digital Sky Survey (SDSS) Data Release 6 data. After constructing the four galaxy catalogs that are different in the ranges of magnitudes and photometric redshifts to study possible systematics, we found that the most robust sample against systematics indicates no dipole anisotropy in the galaxy distribution. This finding is consistent with the expectation from the concordance Lambda-dominated cold dark matter model. Finally we argue that an almost full-sky galaxy survey such as LSST may allow for a significant detection of the aberration effect of the CMB dipole having the precision of constraining the angular direction to ~ 20 degrees in radius. Assuming a hypothetical LSST galaxy survey, we find that this method can confirm or reject the result implied from a stacked analysis of the kinetic Sunyaev-Zel'dovich effect of X-ray luminous clusters in Kashlinsky et al. (2008,2009) if the implied cosmic bulk flow is not extended out to the horizon.Comment: 20 pages, 11 figures; 24 pages, added a couple of references and 2 figures. Revised version in response to the referee's comments. Resubmitted to Phys. Rev.
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