7 research outputs found

    Multiple emission lines of Hα\alpha emitters at z∼2.3z \sim 2.3 from the broad and medium-band photometry in the ZFOURGE Survey

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    We present a multiple emission lines study of ∼\sim1300 Hα\alpha emitters (HAEs) at z∼2.3z \sim 2.3 in the ZFOURGE survey. In contrast to the traditional spectroscopic method, our sample is selected based on the flux excess in the ZFOURGE-KsK_s broad-band data relative to the best-fit stellar continuum. Using the same method, we also extract the strong diagnostic emission lines for these individual HAEs: [OIII]λλ4959,5007\lambda\lambda4959,5007, [OII]λλ3726,3729\lambda\lambda3726,3729. Our measurements exhibit good consistency with those obtained from spectroscopic surveys. We investigate the relationship between the equivalent widths (EWs) of these emission lines and various galaxy properties, including stellar mass, stellar age, star formation rate (SFR), specific SFR (sSFR), ionization states (O32). We have identified a discrepancy between between HAEs at z∼2.3z\sim2.3 and typical local star-forming galaxy observed in the SDSS, suggesting the evolution of lower gas-phase metallicity (ZZ) and higher ionization parameters (UU) with redshift. Notably, we have observed a significant number of low-mass HAEs exhibiting exceptionally high EW[OIII]EW_{\mathrm{[OIII]}}. Their galaxy properties are comparable to those of extreme objects, such as extreme O3 emitters (O3Es) and Lyα\alpha emitters (LAEs) at z≃2−3z\simeq2-3. Considering that these characteristics may indicate potential strong Lyman continuum (LyC) leakage, higher redshift anaglogs of the low-mass HAEs could be significant contributors to the cosmic reionization. Further investigations on this particular population are required to gain a clearer understanding of galaxy evolution and cosmic reionization.Comment: 24 pages, 13 figures, submitted to Ap

    Environmental impact on star-forming galaxies in a z∼0.9z \sim 0.9 cluster during course of galaxy accretion

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    Galaxies change their properties as they assemble into clusters. In order to understand the physics behind that, we need to go back in time and observe directly what is occurring in galaxies as they fall into a cluster. We have conducted a narrow-band and JJ-band imaging survey on a cluster CL1604-D at z=0.923z=0.923 using a new infrared instrument SWIMS installed at the Subaru Telescope. The narrow-band filter, NB1261, matches to Hα\alpha emission from the cluster at z=0.923z=0.923. Combined with a wide range of existing data from various surveys, we have investigated galaxy properties in and around this cluster in great detail. We have identified 27 Hα\alpha emitters associated with the cluster. They have significant overlap with MIPS 24μ\mum sources and are located exclusively in the star forming regime on the rest-frame UVJUVJ diagram. We have identified two groups of galaxies near the cluster in the 2D spatial distribution and the phase-space diagram, which are likely to be in-falling to the cluster main body. We have compared various physical properties of star forming galaxies, such as specific star formation rates (burstiness) and morphologies (merger) as a function of environment; cluster center, older group, younger group, and the field. As a result, a global picture has emerged on how the galaxy properties are altered as they assemble into a denser region. This includes the occurrence of mergers, enhancement of star formation activity, excursion to the dusty starburst phase, and eventual quenching to a passive phase.Comment: 19 pages, 15 figures. Accepted for publication in ApJ. Error bars in Table 2 correcte

    Classifying Microscopic Images of Reactive Lymphocytosis Using Two-Step Tandem AI Models

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    The practical applications of automatic recognition and categorization technology for next-generation systems are desired in the clinical laboratory. We approached the identification of reactive lymphocytosis using artificial intelligence (AI) technology and studied its clinical usefulness for blood smear screening. This study created one- and two-step AI models for the identification of reactive lymphocytosis. The ResNet-101 model was applied for deep learning. The original image set for supervised AI training consisted of 5765 typical nucleated blood cell images. The subjects for clinical assessment were 25 healthy cases, 25 erythroblast cases, and 25 reactive lymphocytosis cases. The total accuracy (mean ± standard deviation) of the one- and two-step models were 0.971 ± 0.047 and 0.977 ± 0.024 in healthy, 0.938 ± 0.040 and 0.978 ± 0.018 in erythroblast, and 0.856 ± 0.056 and 0.863 ± 0.069 in reactive lymphocytosis cases, respectively. The two-step AI model showed a sensitivity of 0.960 and a specificity of 1.000 between healthy and reactive lymphocytosis cases. As our two-step tandem AI model showed high performance for identifying reactive lymphocytosis in blood smear screening, we plan to apply this method to the development of AI models to differentiate reactive and neoplastic lymphocytosis

    Successful engraftment of epithelial cells derived from autologous rabbit buccal mucosal tissue, encapsulated in a polymer scaffold in a rabbit model of a urethral stricture, transplanted using the transurethral approach

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    Background: A pilot study reported an autologous buccal mucosal cell transplant in humans through the trans-urethral route using the buccal epithelium expanded and encapsulated in scaffold—hybrid approach to urethral stricture (BEES-HAUS), a minimally invasive approach to treat urethral stricture. Although successful outcomes were achieved in that study, for further validation, it is essential to prove that the transplanted buccal epithelium was engrafted over the urothelium through histological examination of the urethra, harvested post-transplant, which is infeasible in humans. Herein, we report the successful creation of an animal model of urethral stricture and the engraftment of epithelial cells derived from autologous buccal mucosal tissue, encapsulated in a thermo-reversible gelation polymer (TGP) scaffold, transplanted by trans-urethral route. Methods: An animal model of urethral stricture was created in Japanese white male rabbits using electro-coagulation. Buccal tissue was harvested from the rabbits and subjected to enzyme digestion, followed by 5–7 days of in vitro culture in conventional two-dimensional (2D) culture and in a 3D platform of thermo-reversible gelation polymer (3D-TGP) culture. The cells harvested from the groups were mixed and encapsulated and transplanted with TGP, by transurethral catheterization. Fourteen days later, the urethra was harvested and subjected to histological examination. The buccal biopsy tissue, cells after digestion and cells post-culture were also subjected to histological examination. Urethrogram and endoscopy images were recorded at different time points. Results: The stricture was successfully created, with the coagulated area markedly stenosed. Histological staining of the cells after in vitro processing showed that the cells grew with native epithelial and rounded cell morphology in 3D-TGP while they differentiated into fibroblast like-cells in 2D culture. Histological staining of the urethral tissue after transplantation revealed the engraftment of the transplanted buccal mucosal cells, with stratified squamous epithelium over the specialized stratified urothelium in the urethrotomy site. Conclusion: We used histology to prove the successful engraftment of TGP-encapsulated buccal mucosal epithelial cells in an animal model of urethral injury with healing of the injured tissue. The model of urethral stricture and cell therapy, using a transurethral approach, recapitulates the previously reported BEES-HAUS approach and lays the foundation for larger multi-centric translational clinical studies

    EMPRESS. VIII. A New Determination of Primordial He Abundance with Extremely Metal-Poor Galaxies: A Suggestion of the Lepton Asymmetry and Implications for the Hubble Tension

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    The primordial He abundance YPY_P is a powerful probe of cosmology. Currently, YPY_P is best determined by observations of metal-poor galaxies, while there are only a few known local extremely metal-poor (<0.1Z⊙<0.1 Z_\odot) galaxies (EMPGs) having reliable He/H measurements with HeIλ\lambda10830 near-infrared (NIR) emission. Here we present deep Subaru NIR spectroscopy and He/H determinations for 10 EMPGs, combining the existing optical data and the Markov chain Monte Carlo algorithm. Adding the existing 3 EMPGs and 51 moderately metal-poor (0.1−0.4Z⊙0.1-0.4 Z_\odot) galaxies with reliable He/H estimates, we obtain YP=0.2379−0.0030+0.0031Y_P=0.2379^{+0.0031}_{-0.0030} by linear regression in the (He/H)-(O/H) plane, where our observations increase the number of EMPGs from 3 to 13 anchoring He/H of the most metal-poor gas in galaxies. Although our YPY_P measurement and previous measurements are consistent, our result is slightly (~ 1σ\sigma) smaller due to our EMPGs. Including the existing primordial deuterium DPD_P constraints, we estimate the effective number of neutrino species to be Neff=2.41−0.21+0.19N_{eff}=2.41^{+0.19}_{-0.21} showing a > 2 σ\sigma tension with the Standard Model value (Neff=3.046N_{eff}=3.046), which may be a hint of an asymmetry in electron-neutrino νe\nu_e and anti-electron neutrino νˉe\bar{\nu}_e. Allowing the degeneracy parameter of electron-neutrino ξe\xi_e to vary as well as NeffN_{eff} and the baryon-to-photon ratio η\eta, we obtain ξe\xi_e = 0.05−0.03+0.030.05^{+0.03}_{-0.03}, Neff=3.22−0.30+0.33N_{eff}=3.22^{+0.33}_{-0.30}, and η×1010=6.13−0.04+0.04\eta\times10^{10}=6.13^{+0.04}_{-0.04} from the YPY_P and DPD_P measurements with a prior of η\eta taken from Planck Collaboration et al. (2020). Our constraints suggest a νe−νˉe\nu_e - \bar{\nu}_e asymmetry and allow for a high value of NeffN_{eff} within the 1σ\sigma level, which could mitigate the Hubble tension.Comment: 19 pages, 7 figures, submitted to Ap
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