226 research outputs found

    Cosmic Galaxy-IGM HI Relation at z∌2−3{\it{z}}\sim 2-3 Probed in the COSMOS/UltraVISTA 1.61.6 deg2^2 Field

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    We present spatial correlations of galaxies and IGM HI in the COSMOS/UltraVISTA 1.62 deg2^2 field. Our data consist of 13,415 photo-zz galaxies at z∌2−3z\sim2-3 with Ks<23.4K_s<23.4 and the Lyα\alpha forest absorptions in the background quasar spectra selected from SDSS data with no signature of damped Lyα\alpha system contamination. We estimate a galaxy overdensity ÎŽgal\delta_{gal} in an impact parameter of 2.5 pMpc, and calculate the Lyα\alpha forest fluctuations ή⟹F⟩\delta_{\langle F\rangle} whose negative values correspond to the strong Lyα\alpha forest absorptions. We identify weak evidence of an anti-correlation between ÎŽgal\delta_{gal} and ή⟹F⟩\delta_{\langle F\rangle} with a Spearman's rank correlation coefficient of −0.39-0.39 suggesting that the galaxy overdensities and the Lyα\alpha forest absorptions positively correlate in space at the ∌90%\sim90\% confidence level. This positive correlation indicates that high-zz galaxies exist around an excess of HI gas in the Lyα\alpha forest. We find four cosmic volumes, dubbed AobsA_{obs}-DobsD_{obs}, that have extremely large (small) values of ÎŽgal≃0.8\delta_{gal} \simeq0.8 (−1-1) and ή⟹F⟩\delta_{\langle F\rangle} ≃0.1\simeq0.1 (−0.4-0.4), three out of which, BobsB_{obs}-DobsD_{obs}, significantly depart from the correlation, and weaken the correlation signal. We perform cosmological hydrodynamical simulations, and compare with our observational results. Our simulations reproduce the correlation, agreeing with the observational results. Moreover, our simulations have model counterparts of AobsA_{obs}-DobsD_{obs}, and suggest that the observations pinpoint, by chance, a galaxy overdensity like a proto-cluster, gas filaments lying on the sightline, a large void, and orthogonal low-density filaments. Our simulations indicate that the significant departures of BobsB_{obs}-DobsD_{obs} are produced by the filamentary large-scale structures and the observation sightline effects.Comment: 14 pages, 12 figures. Accepted for publication in Ap

    Tendency of Adhesive Particles on the Liquid Wall Layer in the Turbulent Flow Channel

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    The experimental investigation and simulation model approach were carried out to investigate the behavior of the fine particles to ad­here on the layer of liquid on the wall in gas-solid two-phase flow. Polymethyl methacrylate having two different mean-diameters of 20 mm and of 50mm was used for measurement. By using continuous feeding sys­tem, the fine particles were entrained and mixed with the air in the duct. Experiment for solid particle gas with two-phase flow in room temperature was carried out to make a clear turbulent effect for particle adhering behavior to wall side having a high-viscosity liquid layer. These phenomena were also investigated by the simulation model which represented the experimental condition for two-phase flow and using k-Δ two equation models for turbulent flow. The experimental result showed that adhered particle quantity depends on particle feeding rate. The result of simulation model also showed the same tendency. The relation of the various particles feeding rate and capture rate were also described

    Similarities and uniqueness of Lyα\alpha emitters among star-forming galaxies at z=2.5

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    We conducted a deep narrow-band imaging survey with the Subaru Prime Focus Camera on the Subaru Telescope and constructed a sample of Lyα\alpha emitters (LAEs) at z=2.53 in the UDS-CANDELS field where a sample of Hα\alpha emitters (HAEs) at the same redshift is already obtained from our previous narrow-band observation at NIR. The deep narrow-band and multi broadband data allow us to find LAEs of stellar masses and star-formation rates (SFRs) down to ≳\gtrsim10810^8 M⊙_\odot and ≳\gtrsim0.2 M⊙_\odot/yr, respectively. We show that the LAEs are located along the same mass-SFR sequence traced by normal star-forming galaxies such as HAEs, but towards a significantly lower mass regime. Likewise, LAEs seem to share the same mass--size relation with typical star-forming galaxies, except for the massive LAEs, which tend to show significantly compact sizes. We identify a vigorous mass growth in the central part of LAEs: the stellar mass density in the central region of LAEs increases as their total galaxy mass grows. On the other hand, we see no Lyα\alpha line in emission for most of the HAEs. Rather, we find that the Lyα\alpha feature is either absent or in absorption (Lyα\alpha absorbers; LAAs), and its absorption strength may increase with reddening of the UV continuum slope. We demonstrate that a deep Lyα\alpha narrow-band imaging like this study is able to search for not only LAEs but also LAAs in a certain redshift slice. This work suggests that LAEs trace normal star-forming galaxies in the low-mass regime, while they remain as a unique population because the majority of HAEs are not LAEs.Comment: 20 pages, 18 figures, 3 tables, accepted for publication in MNRA

    Spectroscopy of eta'-nucleus bound states at GSI-SIS

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    The eta' meson mass may be reduced due to partial restoration of chiral symmetry. If this is the case, an eta'-nucleus system may form a nuclear bound state. We plan to carry out a missing-mass spectroscopy with the 12C(p,d) reaction at GSI-SIS. Peak structures corresponding to such a bound state may be observed even in an inclusive measurement, if the decay width is narrow enough.Comment: 4 pages, 2 figures, to appear in the proceedings of MESON2012 (12th International Workshop on Meson Production, Properties and Interaction), Krakow, Polan

    Porcine Enamel Protein Fractions Contain Transforming Growth Factor‐ÎČ1

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141064/1/jper1688.pd
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