1,893 research outputs found
Detection of Far Infrared Emission from Galaxies and Quasars in the Galactic Extinction Map by Stacking Analysis
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, , 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 [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
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
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
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?
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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