We present a statistical study of velocities of Lyα, interstellar (IS) absorption, and nebular lines and gas covering fraction for Lyα emitters (LAEs) at z ≃ 2. We make a sample of 22 LAEs with a large Lyα equivalent width (EW) of 50Å based on our deep Keck/LRIS observations, in conjunction with spectroscopic data from the Subaru/FMOS program and the literature. We estimate the average velocity offset of Lyα from a systemic redshift determined with nebular lines to be ∆v Lyα = 234 ± 9 km s −1 . Using a Kolmogorv-Smirnov test, we confirm the previous claim of Hashimoto et al. (2013) that the average ∆v Lyα of LAEs is smaller than that of LBGs. Our LRIS data successfully identify blue-shifted multiple IS absorption lines in the UV continua of four LAEs on an individual basis. The average velocity offset of IS absorption lines from a systemic redshift is ∆v IS = 204 ± 27 km s −1 , indicating LAE's gas outflow with a velocity comparable to typical LBGs. Thus, the ratio, R Lyα IS ≡ ∆v Lyα /∆v IS of LAEs, is around unity, suggestive of low impacts on Lyα transmission by resonant scattering of neutral hydrogen in the IS medium. We find an anti-correlation between Lyα EW and the covering fraction, f c , estimated from the depth of absorption lines, where f c is an indicator of average neutral hydrogen column density, N HI . The results of our study support the idea that N HI is a key quantity determining Lyα emissivity.

We present the results of a Lyα profile analysis of 12 Lyα emitters (LAEs) at z ∼ 2.2 with highresolution Lyα spectra. We find that all 12 objects have a Lyα profile with the main peak redward of the systemic redshift defined by nebular lines, and five have a weak, secondary peak blueward of the systemic redshift (blue bump). The average velocity offset of the red main peak (the blue bump, if any) with respect to the systemic redshift is ∆v Lyα,r = 174±19 km s −1 (∆v Lyα,b = −316±45 km s −1 ), which is smaller than (comparable to) that of Lyman-break galaxies (LBGs). The outflow velocities inferred from metal absorption lines in three individual and one stacked spectra are comparable to those of LBGs. The uniform expanding shell model constructed by Verhamme et al. (2006) reproduces not only the Lyα profiles but also other observed quantities including the outflow velocity and the FWHM of nebular lines for the non-blue bump objects. On the other hand, the model predicts too high FWHMs of nebular lines for the blue bump objects, although this discrepancy may disappear if we introduce additional Lyα photons produced by gravitational cooling. We show that the small ∆v Lyα,r values of our sample can be explained by low neutral-hydrogen column densities of log(N HI ) = 18.9 cm −2 on average. This value is more than one order of magnitude lower than those of LBGs but is consistent with recent findings that LAEs have high ionization parameters and low Hi gas masses. This result suggests that low N HI values, giving reduced numbers of resonant scattering of Lyα photons, are the key to the strong Lyα emission of LAEs.

We present average stellar population properties and dark matter halo masses of z ∼ 2 Lyα emitters (LAEs) from SED fitting and clustering analysis, respectively, using ≃ 1250 objects (N B387 ≤ 25.5) in four separate fields of ≃ 1 deg 2 in total. With an average stellar mass of 10.2 ± 1.8 × 10 8 M ⊙ and star formation rate of 3.4 ± 0.4 M ⊙ yr −1 , the LAEs lie on an extrapolation of the star-formation main sequence (MS) to low stellar mass. Their effective dark matter halo mass is estimated to be 4.010 M ⊙ with an effective bias of 1.22−0.18 which is lower than that of z ∼ 2 LAEs (1.8 ± 0.3), obtained by a previous study based on a three times smaller survey area, with a probability of 96%. However, the difference in the bias values can be explained if cosmic variance is taken into account. If such a low halo mass implies a low HI gas mass, this result appears to be consistent with the observations of a high Lyα escape fraction. With the low halo masses and ongoing star formation, our LAEs have a relatively high stellar-to-halo mass ratio (SHMR) and a high efficiency of converting baryons into stars. The extended Press-Schechter formalism predicts that at z = 0 our LAEs are typically embedded in halos with masses similar to that of the Large Magellanic Cloud (LMC); they will also have c 20xx. Astronomical Society of Japan.

This study considers the use of deep learning to diagnose osteoporosis from hip radiographs, and whether adding clinical data improves diagnostic performance over the image mode alone. For objective labeling, we collected a dataset containing 1131 images from patients who underwent both skeletal bone mineral density measurement and hip radiography at a single general hospital between 2014 and 2019. Osteoporosis was assessed from the hip radiographs using five convolutional neural network (CNN) models. We also investigated ensemble models with clinical covariates added to each CNN. The accuracy, precision, recall, specificity, negative predictive value (npv), F1 score, and area under the curve (AUC) score were calculated for each network. In the evaluation of the five CNN models using only hip radiographs, GoogleNet and EfficientNet b3 exhibited the best accuracy, precision, and specificity. Among the five ensemble models, EfficientNet b3 exhibited the best accuracy, recall, npv, F1 score, and AUC score when patient variables were included. The CNN models diagnosed osteoporosis from hip radiographs with high accuracy, and their performance improved further with the addition of clinical covariates from patient records.