21 research outputs found

    AGN number fraction in galaxy groups and clusters at z < 1.4 from the Subaru Hyper Suprime-Cam survey

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    One of the key questions on active galactic nuclei (AGN) in galaxy clusters is how AGN could affect the formation and evolution of member galaxies and galaxy clusters in the history of the Universe. To address this issue, we investigate the dependence of AGN number fraction (fAGNf_{\rm AGN}) on cluster redshift (zclz_{\rm cl}) and distance from the cluster center (R/R200R/R_{\rm 200}). We focus on more than 27,000 galaxy groups and clusters at 0.1<zcl<1.40.1 < z_{\rm cl} < 1.4 with more than 1 million member galaxies selected from the Subaru Hyper Suprime-Cam. By combining various AGN selection methods based on infrared (IR), radio, and X-ray data, we identify 2,688 AGN. We find that (i) fAGNf_{\rm AGN} increases with zclz_{\rm cl} and (ii) fAGNf_{\rm AGN} decreases with R/R200R/R_{\rm 200}. The main contributors to the rapid increase of fAGNf_{\rm AGN} towards high-zz and cluster center are IR- and radio-selected AGN, respectively. Those results indicate that the emergence of the AGN population depends on the environment and redshift, and galaxy groups and clusters at high-zz play an important role in AGN evolution. We also find that cluster-cluster mergers may not drive AGN activity in at least the cluster center, while we have tentative evidence that cluster-cluster mergers would enhance AGN activity in the outskirts of (particularly massive) galaxy clusters.Comment: 16 pages, 21 figures, and 2 tables, accepted for publication in PAS

    SlLAX1 is Required for Normal Leaf Development Mediated by Balanced Adaxial and Abaxial Pavement Cell Growth in Tomato

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    Leaves are the major plant organs with a primary function for photosynthesis. Auxin controls various aspects of plant growth and development, including leaf initiation, expansion and differentiation. Unique and intriguing auxin features include its polar transport, which is mainly controlled by the AUX1/LAX and PIN gene families as influx and efflux carriers, respectively. The role of AUX1/LAX genes in root development is well documented, but the role of these genes in leaf morphogenesis remains unclear. Moreover, most studies have been conducted in the plant model Arabidopsis thaliana, while studies in tomato are still scarce. In this study, we isolated six lines of the allelic curly leaf phenotype ‘curl’ mutants from a γ-ray and EMS (ethyl methanesulfonate) mutagenized population. Using a map-based cloning strategy combined with exome sequencing, we observed that a mutation occurred in the SlLAX1 gene (Solyc09g014380), which is homologous to an Arabidopsis auxin influx carrier gene, AUX1 (AtAUX1). Characterization of six alleles of single curl mutants revealed the pivotal role of SlLAX1 in controlling tomato leaf flatness by balancing adaxial and abaxial pavement cell growth, which has not been reported in tomato. Using TILLING (Targeting Induced Local Lesions IN Genome) technology, we isolated an additional mutant allele of the SlLAX1 gene and this mutant showed a curled leaf phenotype similar to other curl mutants, suggesting that Solyc09g014380 is responsible for the curl phenotype. These results showed that SlLAX1 is required for normal leaf development mediated by balanced adaxial and abaxial pavement cell growth in tomato

    Adhesion of Atmospheric Micro-Contaminants on SUS304 Steel and Removal by UV Illumination * 1

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    Micro-contaminants on SUS304 stainless steel were observed and confirmed by atomic force microscope, and the micro-contaminant removal was carried out by ultraviolet (UV) illumination. With an increase in the holding time in air, particle-and film-like micro-contaminants appeared and their amount increased on the specimen surface. Then, the amount of particle-like contaminants decreased and finally almost all the surface was covered by film-like contaminants. The amount of micro-contaminants on the specimen surface decreased with an increase in the UV illumination time, with extensive removal of the organic substance in the contaminants but leaving part of the contained water in the contaminants. The micro-contaminants slowly re-adhered on the treated surface when the surface was re-exposed to air, with a longer period than 172 ks for the recovery to the state before the UV illumination. The surface for macro-droplets after the UV illumination became hydrophilic, while no large change of the wettability for micro-droplets on the same surface can be observed
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