235 research outputs found

    An updated measurement of the Hubble constant from near-infrared observations of Type Ia supernovae

    Get PDF
    We present a measurement of the Hubble constant (H0H_0) using type Ia supernova (SNe Ia) in the near-infrared (NIR) from the recently updated sample of SNe Ia in nearby galaxies with distances measured via Cepheid period-luminosity relations by the SHOES project. We collect public near-infrared photometry of up to 19 calibrator SNe Ia and further 57 SNe Ia in the Hubble flow (z>0.01z>0.01), and directly measure their peak magnitudes in the JJ and HH band by Gaussian processes and spline interpolation. Calibrator peak magnitudes together with Cepheid-based distances are used to estimate the average absolute magnitude in each band, while Hubble-flow SNe are used to constrain the zero-point intercept of the magnitude-redshift relation. Our baseline result of H0H_0 is 72.3±1.472.3\pm1.4 (stat) ±1.4\pm1.4 (syst) km s1^{-1} Mpc1^{-1} in the JJ band and 72.3±1.372.3\pm1.3 (stat) ±1.4\pm1.4 (syst) km s1^{-1} Mpc1^{-1} in the HH band, where the systematic uncertainties include the standard deviation of up to 21 variations of the analysis, the 0.7\% distance scale systematic from SHOES Cepheid anchors, a photometric zeropoint systematic, and a cosmic variance systematic. Our final measurement represents a measurement with a precision of 2.8\% in both bands. The variant with the largest change in H0H_0 is when limiting the sample to SNe from CSP and CfA programmes, noteworthy because these are the best calibrated, yielding H075H_0\sim75 km s1^{-1} Mpc1^{-1} in both bands. We demonstrate stretch and reddening corrections are still useful in the NIR to standardize SN Ia NIR peak magnitudes. Based on our results, in order to improve the precision of the H0H_0 measurement with SNe Ia in the NIR in the future, we would need to increase the number of calibrator SNe Ia, be able to extend the Hubble-Lema\^itre diagram to higher-z, and include standardization procedures to help reducing the NIR intrinsic scatter.Comment: 15 pages, 8 figures. Accepted in A&

    Mental Health of Parents and Life Satisfaction of Children: A Within-Family Analysis of Intergenerational Transmission of Well-Being

    Get PDF
    This paper addresses the extent to which there is an intergenerational transmission of mental health and subjective well-being within families. Specifically it asks whether parents’ own mental distress influences their child’s life satisfaction, and vice versa. Whilst the evidence on daily contagion of stress and strain between members of the same family is substantial, the evidence on the transmission between parental distress and children’s well-being over a longer period of time is sparse. We tested this idea by examining the within-family transmission of mental distress from parent to child’s life satisfaction, and vice versa, using rich longitudinal data on 1,175 British youths. Results show that parental distress at year t-1 is an important determinant of child’s life satisfaction in the current year. This is true for boys and girls, although boys do not appear to be affected by maternal distress levels. The results also indicated that the child’s own life satisfaction is related with their father’s distress levels in the following year, regardless of the gender of the child. Finally, we examined whether the underlying transmission correlation is due to shared social environment, empathic reactions, or transmission via parent-child interaction

    Anthropogenic Space Weather

    Full text link
    Anthropogenic effects on the space environment started in the late 19th century and reached their peak in the 1960s when high-altitude nuclear explosions were carried out by the USA and the Soviet Union. These explosions created artificial radiation belts near Earth that resulted in major damages to several satellites. Another, unexpected impact of the high-altitude nuclear tests was the electromagnetic pulse (EMP) that can have devastating effects over a large geographic area (as large as the continental United States). Other anthropogenic impacts on the space environment include chemical release ex- periments, high-frequency wave heating of the ionosphere and the interaction of VLF waves with the radiation belts. This paper reviews the fundamental physical process behind these phenomena and discusses the observations of their impacts.Comment: 71 pages, 35 figure

    Prominent radiative contributions from multiply-excited states in laser-produced tin plasma for nanolithography

    Get PDF
    Extreme ultraviolet (EUV) lithography is currently entering high-volume manufacturing to enable the continued miniaturization of semiconductor devices. The required EUV light, at 13.5 nm wavelength, is produced in a hot and dense laser-driven tin plasma. The atomic origins of this light are demonstrably poorly understood. Here we calculate detailed tin opacity spectra using the Los Alamos atomic physics suite ATOMIC and validate these calculations with experimental comparisons. Our key finding is that EUV light largely originates from transitions between multiply-excited states, and not from the singly-excited states decaying to the ground state as is the current paradigm. Moreover, we find that transitions between these multiply-excited states also contribute in the same narrow window around 13.5 nm as those originating from singly-excited states, and this striking property holds over a wide range of charge states. We thus reveal the doubly magic behavior of tin and the origins of the EUV light

    Living on the edge: precariousness and why it matters for health

    Get PDF
    The post-war period in Europe, between the late 1940s and the 1970s, was characterised by an expansion of the role of by the state, protecting its citizens from risks of unemployment, poverty, homelessness, and food insecurity. This security began to erode in the 1980s as a result of privatisation and deregulation. The withdrawal of the state further accelerated after the 2008 financial crisis, as countries began pursuing deep austerity. The result has been a rise in what has been termed ‘precariousness’. Here we review the development of the concept of precariousness and related phenomena of vulnerability and resilience, before reviewing evidence of growing precariousness in European countries. It describes a series of studies of the impact on precariousness on health in domains of employment, housing, and food, as well as natural experiments of policies that either alleviate or worsen these impacts. It concludes with a warning, drawn from the history of the 1930s, of the political consequences of increasing precariousness in Europe and North America

    Erratum to: EuPRAXIA Conceptual Design Report – Eur. Phys. J. Special Topics 229, 3675-4284 (2020), https://doi.org/10.1140/epjst/e2020-000127-8

    Get PDF
    International audienceThe online version of the original article can be found at http://https://doi.org/10.1140/epjst/e2020-000127-8</A

    Coordinating Environmental Genomics and Geochemistry Reveals Metabolic Transitions in a Hot Spring Ecosystem

    Get PDF
    We have constructed a conceptual model of biogeochemical cycles and metabolic and microbial community shifts within a hot spring ecosystem via coordinated analysis of the “Bison Pool” (BP) Environmental Genome and a complementary contextual geochemical dataset of ∼75 geochemical parameters. 2,321 16S rRNA clones and 470 megabases of environmental sequence data were produced from biofilms at five sites along the outflow of BP, an alkaline hot spring in Sentinel Meadow (Lower Geyser Basin) of Yellowstone National Park. This channel acts as a >22 m gradient of decreasing temperature, increasing dissolved oxygen, and changing availability of biologically important chemical species, such as those containing nitrogen and sulfur. Microbial life at BP transitions from a 92°C chemotrophic streamer biofilm community in the BP source pool to a 56°C phototrophic mat community. We improved automated annotation of the BP environmental genomes using BLAST-based Markov clustering. We have also assigned environmental genome sequences to individual microbial community members by complementing traditional homology-based assignment with nucleotide word-usage algorithms, allowing more than 70% of all reads to be assigned to source organisms. This assignment yields high genome coverage in dominant community members, facilitating reconstruction of nearly complete metabolic profiles and in-depth analysis of the relation between geochemical and metabolic changes along the outflow. We show that changes in environmental conditions and energy availability are associated with dramatic shifts in microbial communities and metabolic function. We have also identified an organism constituting a novel phylum in a metabolic “transition” community, located physically between the chemotroph- and phototroph-dominated sites. The complementary analysis of biogeochemical and environmental genomic data from BP has allowed us to build ecosystem-based conceptual models for this hot spring, reconstructing whole metabolic networks in order to illuminate community roles in shaping and responding to geochemical variability
    corecore