Within one billion years of the Big Bang, intergalactic hydrogen was ionized by sources emitting ultraviolet and higher energy photons. This was the final phenomenon to globally affect all the baryons (visible matter) in the Universe.It is referred to as cosmic reionization and is an integral component of cosmology. It is broadly expected that intrinsically faint galaxies were the primary ionizing sources due to their abundance in this epoch. However, at the highest redshifts (z > 7.5; lookback time 13.1 Gyr), all galaxies with spectroscopic confirmations to date are intrinsically bright and therefore not necessarily representative of the general population. Here we report the unequivocal spectroscopic detection of a low luminosity galaxy at z > 7.5. We detected the Lyman-alpha (Lyα) emission line at ∼ 10504Å in two separate observations 1 arXiv:1704.02970v1 [astro-ph.GA]

We present the first study of the spatial distribution of star formation in z ∼ 0.5 cluster galaxies. The analysis is based on data taken with the Wide Field Camera 3 as part of the Grism Lens-Amplified Survey from Space (GLASS). We illustrate the methodology by focusing on two clusters (MACS0717.5+3745 and MACS1423.8+2404) with different morphologies (one relaxed and one merging) and use foreground and background galaxies as field control sample. The cluster+field sample consists of 42 galaxies with stellar masses in the range 10 8 -10 11 M , and star formation rates in the range 1-20 M yr −1 . Both in clusters and in the field, Hα is more extended than the rest-frame UV continuum in 60% of the cases, consistent with diffuse star formation and inside out growth. In ∼ 20% of the cases, the Hα emission appears more extended in cluster galaxies than in the field, pointing perhaps to ionized gas being stripped and/or star formation being enhanced at large radii. The peak of the Hα emission and that of the continuum are offset by less than 1 kpc. We investigate trends with the hot gas density as traced by the X-ray emission, and with the surface mass density as inferred from gravitational lens models and find no conclusive results. The diversity of morphologies and sizes observed in Hα illustrates the complexity of the environmental process that regulate star formation. Upcoming analysis of the full GLASS dataset will increase our sample size by almost an order of magnitude, verifying and strengthening the inference from this initial dataset.

Parenting stress is the experience of discomfort or distress that results from the demands associated with the role of parenting. Although there are numerous parenting stress scales, relatively few scales have been developed with consideration of the Chinese cultural context. This study aimed to develop and validate the Chinese Parenting Stress Scale (CPSS) with a multidimensional and hierarchical structure for Mainland Chinese preschoolers’ parents ( N = 1,427, Mage = 35.63 years, SD = 4.69). In Study 1, a theoretical model and an initial 118 items were developed, drawing on prior research and existing measures of parenting stress. Exploratory factor analysis yielded 15 first-order factors with 60 items. In Study 2, confirmatory factor analyses supported a higher order solution consisting of 15 first-order factors covering four domains: Child Development (12 items), Difficult Child (16 items), Parent–Child Interaction (12 items), and Parent’s Readjustment to Life (20 items). Measurement invariance indicated no gender differences between parents for the scale scores. The convergent, discriminant, and criteria validity of the CPSS scores was supported by its association with related variables in the expected directions. Moreover, the CPSS scores added significant incremental variance in predicting somatization, anxiety, and child’s emotional symptoms more so than the Parenting Stress Index–Short Form-15. The CPSS total and subscale scores all had acceptable Cronbach’s αs in both samples. The overall findings support the CPSS as a psychometrically sound tool.