We present an update to the ultraviolet-to-radio database of global broadband photometry for the 79 nearby galaxies that comprise the union of the KINGFISH (Key Insights on Nearby Galaxies: A ...Far-Infrared Survey with Herschel) and SINGS (Spitzer Infrared Nearby Galaxies Survey) samples. The 34-band data set presented here includes contributions from observational work carried out with a variety of facilities including GALEX, SDSS, Pan-STARRS1, NOAO, 2MASS, Wide-Field Infrared Survey Explorer, Spitzer, Herschel, Planck, JCMT, and the VLA. Improvements of note include recalibrations of previously published SINGS BVRCIC and KINGFISH far-infrared/submillimeter photometry. Similar to previous results in the literature, an excess of submillimeter emission above model predictions is seen primarily for low-metallicity dwarf or irregular galaxies. This 33-band photometric data set for the combined KINGFISH+SINGS sample serves as an important multiwavelength reference for the variety of galaxies observed at low redshift. A thorough analysis of the observed spectral energy distributions is carried out in a companion paper.
Large experimental programmes in the fields of nuclear and particle physics search for evidence of physics beyond that explained by current theories. The observation of the Higgs boson completed the ...set of particles predicted by the standard model, which currently provides the best description of fundamental particles and forces. However, this theory's limitations include a failure to predict fundamental parameters, such as the mass of the Higgs boson, and the inability to account for dark matter and energy, gravity, and the matter-antimatter asymmetry in the Universe, among other phenomena. These limitations have inspired searches for physics beyond the standard model in the post-Higgs era through the direct production of additional particles at high-energy accelerators, which have so far been unsuccessful. Examples include searches for supersymmetric particles, which connect bosons (integer-spin particles) with fermions (half-integer-spin particles), and for leptoquarks, which mix the fundamental quarks with leptons. Alternatively, indirect searches using precise measurements of well predicted standard-model observables allow highly targeted alternative tests for physics beyond the standard model because they can reach mass and energy scales beyond those directly accessible by today's high-energy accelerators. Such an indirect search aims to determine the weak charge of the proton, which defines the strength of the proton's interaction with other particles via the well known neutral electroweak force. Because parity symmetry (invariance under the spatial inversion (x, y, z) → (-x, -y, -z)) is violated only in the weak interaction, it provides a tool with which to isolate the weak interaction and thus to measure the proton's weak charge
. Here we report the value 0.0719 ± 0.0045, where the uncertainty is one standard deviation, derived from our measured parity-violating asymmetry in the scattering of polarized electrons on protons, which is -226.5 ± 9.3 parts per billion (the uncertainty is one standard deviation). Our value for the proton's weak charge is in excellent agreement with the standard model
and sets multi-teraelectronvolt-scale constraints on any semi-leptonic parity-violating physics not described within the standard model. Our results show that precision parity-violating measurements enable searches for physics beyond the standard model that can compete with direct searches at high-energy accelerators and, together with astronomical observations, can provide fertile approaches to probing higher mass scales.
Human immunodeficiency virus-1 (HIV-1) infection disrupts the intestinal immune system, leading to microbial translocation and systemic immune activation. We investigated the impact of HIV-1 ...infection on the intestinal microbiome and its association with mucosal T-cell and dendritic cell (DC) frequency and activation, as well as with levels of systemic T-cell activation, inflammation, and microbial translocation. Bacterial 16S ribosomal DNA sequencing was performed on colon biopsies and fecal samples from subjects with chronic, untreated HIV-1 infection and uninfected control subjects. Colon biopsies of HIV-1-infected subjects had increased abundances of Proteobacteria and decreased abundances of Firmicutes compared with uninfected donors. Furthermore at the genus level, a significant increase in Prevotella and decrease in Bacteroides was observed in HIV-1-infected subjects, indicating a disruption in the Bacteroidetes bacterial community structure. This HIV-1-associated increase in Prevotella abundance was associated with increased numbers of activated colonic T cells and myeloid DCs. Principal coordinates analysis demonstrated an HIV-1-related change in the microbiome that was associated with increased mucosal cellular immune activation, microbial translocation, and blood T-cell activation. These observations suggest that an important relationship exists between altered mucosal bacterial communities and intestinal inflammation during chronic HIV-1 infection.
Leptin is an adipocyte‐derived hormone that acts on the hypothalamus to influence feeding, metabolism and reproduction, but the cellular and molecular targets for the action of leptin in the brain ...have yet to be fully elucidated. Kisspeptins are encoded by the Kiss1 gene, which is expressed in the hypothalamus and has been implicated in the neuroendocrine regulation of gonadotrophin‐releasing hormone secretion. We tested the hypothesis that kisspeptin‐expressing neurones are targets for leptin. First, we examined whether leptin regulates the expression of Kiss1 by comparing levels of KiSS‐1 mRNA in the arcuate nucleus among groups of mice having different circulating levels of leptin: (i) wild‐type (WT); (ii) leptin‐deficient ob/ob; and (iii) ob/ob mice treated with leptin. All mice were castrated to control for endogenous concentrations of gonadal steroids. KiSS‐1 mRNA was significantly reduced in ob/ob compared to WT mice and levels of KiSS‐1 mRNA in ob/ob mice treated with leptin were increased, but not fully restored to that found in WT animals. Second, we performed double‐label in situ hybridisation for KiSS‐1 mRNA and the leptin receptor (Ob‐Rb) mRNA and found that almost one‐half (approximately 40%) of KiSS‐1 mRNA‐expressing cells in the arcuate nucleus expressed Ob‐Rb mRNA. These results demonstrate that KiSS‐1 neurones are direct targets for regulation by leptin and suggest that the reproductive deficits associated with leptin‐deficient states may be attributable, in part, to diminished expression of Kiss1.
The Askaryan Radio Array (ARA) is an ultrahigh energy (UHE, > 1017 eV) neutrino detector designed to observe neutrinos by searching for the radio waves emitted by the relativistic products of ...neutrino-nucleon interactions in Antarctic ice. In this paper, we present constraints on the diffuse flux of ultrahigh energy neutrinos between 1016 and 1021 eV resulting from a search for neutrinos in two complementary analyses, both analyzing four years of data (2013–2016) from the two deep stations (A2, A3) operating at that time. We place a 90% CL upper limit on the diffuse all flavor neutrino flux at 1018 eV of EF(E) = 5.6 × 10−16 cm−2 s−1 sr−1. This analysis includes four times the exposure of the previous ARA result and represents approximately 1 / 5 th the exposure expected from operating ARA until the end of 2022.
The Spitzer Infrared Nearby Galaxies Survey (SINGS) is carrying out a comprehensive multiwavelength survey on a sample of 75 nearby galaxies. The 1-850 km spectral energy distributions (SEDs) are ...presented using broadband imaging data from Spitzer, 2MASS, ISO, IRAS, and SCUBA. The infrared colors derived from the globally integrated Spitzer data are generally consistent with the previous generation of models that were developed using global data for normal star-forming galaxies, although significant deviations are observed. Spitzer's excellent sensitivity and resolution also allow a detailed investigation of the infrared SEDs for various locations within the three large, nearby galaxies NGC 3031 (M81), NGC 5194 (M51), and NGC 7331. A wide variety of spectral shapes is found within each galaxy, especially for NGC 3031, the closest of the three targets and thus the galaxy for which the smallest spatial scales can be explored. Strong correlations exist between the local star formation rate and the infrared colors f sub(u)(70 km)/f sub(u)(160 km) and f sub(u)(24 km)/f sub(u)(160 km), suggesting that the 24 and 70 km emission are useful tracers of the local star formation activity level. Preliminary evidence indicates that variations in the 24 km emission, and not variations in the emission from polycyclic aromatic hydrocarbons at 8 km, drive the variations in the f sub(u)(8.0 km)/f sub(u)(24 km) colors within NGC 3031, NGC 5194, and NGC 7331. If the galaxy-to-galaxy variations in SEDs seen in our sample are representative of the range present at high redshift, then extrapolations of total infrared luminosities and star formation rates from the observed 24 km flux will be uncertain at the factor of 5 level (total range). The corresponding uncertainties using the redshifted 8.0 km flux (e.g., observed 24 km flux for a z = 2 source) are factors of 10-20. Considerable caution should be used when interpreting such extrapolated infrared luminosities.
The most energetic planetary collisions attain shock pressures that result in abundant melting and vaporization. Accurate predictions of the extent of melting and vaporization require knowledge of ...vast regions of the phase diagrams of the constituent materials. To reach the liquid‐vapor phase boundary of silica, we conducted uniaxial shock‐and‐release experiments, where quartz was shocked to a state sufficient to initiate vaporization upon isentropic decompression (hundreds of GPa). The apparent temperature of the decompressing fluid was measured with a streaked optical pyrometer, and the bulk density was inferred by stagnation onto a standard window. To interpret the observed post‐shock temperatures, we developed a model for the apparent temperature of a material isentropically decompressing through the liquid‐vapor coexistence region. Using published thermodynamic data, we revised the liquid‐vapor boundary for silica and calculated the entropy on the quartz Hugoniot. The silica post‐shock temperature measurements, up to entropies beyond the critical point, are in excellent qualitative agreement with the predictions from the decompressing two‐phase mixture model. Shock‐and‐release experiments provide an accurate measurement of the temperature on the phase boundary for entropies below the critical point, with increasing uncertainties near and above the critical point entropy. Our new criteria for shock‐induced vaporization of quartz are much lower than previous estimates, primarily because of the revised entropy on the Hugoniot. As the thermodynamics of other silicates are expected to be similar to quartz, vaporization is a significant process during high‐velocity planetary collisions.
Key Points
We measured the temperature on the liquid‐vapor curve of silica
We calculated the entropy on the quartz Hugoniot
We provide new criteria for shock‐induced vaporization of silica
Neuromyelitis optica (NMO) is an inflammatory autoimmune disease of the central nervous system that preferentially targets the optic nerves and spinal cord. The clinical presentation may suggest ...multiple sclerosis (MS), but a highly specific serum autoantibody against the astrocytic water channel aquaporin-4 present in up to 80% of NMO patients enables distinction from MS. Optic neuritis may occur in either condition resulting in neuro-anatomical retinal changes. Optical coherence tomography (OCT) has become a useful tool for analyzing retinal damage both in MS and NMO. Numerous studies showed that optic neuritis in NMO typically results in more severe retinal nerve fiber layer (RNFL) and ganglion cell layer thinning and more frequent development of microcystic macular edema than in MS. Furthermore, while patients’ RNFL thinning also occurs in the absence of optic neuritis in MS, subclinical damage seems to be rare in NMO. Thus, OCT might be useful in differentiating NMO from MS and serve as an outcome parameter in clinical studies.
We characterize the dust in NGC 628 and NGC 6946, two nearby spiral galaxies in the KINGFISH sample. With data from 3.6 mu m to 500 mu m, dust models are strongly constrained. Using the Draine & Li ...dust model (amorphous silicate and carbonaceous grains), for each pixel in each galaxy we estimate (1) dust mass surface density, (2) dust mass fraction contributed by polycyclic aromatic hydrocarbons, (3) distribution of starlight intensities heating the dust, (4) total infrared (IR) luminosity emitted by the dust, and (5) IR luminosity originating in regions with high starlight intensity. We obtain maps for the dust properties, which trace the spiral structure of the galaxies. The dust models successfully reproduce the observed global and resolved spectral energy distributions (SEDs). The overall dust/H mass ratio is estimated to be 0.0082 + or - 0.0017 for NGC 628, and 0.0063 + or - 0.0009 for NGC 6946, consistent with what is expected for galaxies of near-solar metallicity. Our derived dust masses are larger (by up to a factor of three) than estimates based on single-temperature modified blackbody fits. We show that the SED fits are significantly improved if the starlight intensity distribution includes a (single intensity) "delta function" component. We find no evidence for significant masses of cold dust (T <, ~ 12 K). Discrepancies between PACS and MIPS photometry in both low and high surface brightness areas result in large uncertainties when the modeling is done at PACS resolutions, in which case SPIRE, MIPS70, and MIPS160 data cannot be used. We recommend against attempting to model dust at the angular resolution of PACS.
ABSTRACT We present observations of SN 2015bn (=PS15ae = CSS141223-113342+004332 = MLS150211-113342+004333), a Type I superluminous supernova (SLSN) at redshift z = 0.1136. As well as being one of ...the closest SLSNe I yet discovered, it is intrinsically brighter ( ) and in a fainter galaxy ( ) than other SLSNe at . We used this opportunity to collect the most extensive data set for any SLSN I to date, including densely sampled spectroscopy and photometry, from the UV to the NIR, spanning −50 to +250 days from optical maximum. SN 2015bn fades slowly, but exhibits surprising undulations in the light curve on a timescale of 30-50 days, especially in the UV. The spectrum shows extraordinarily slow evolution except for a rapid transformation between +7 and +20-30 days. No narrow emission lines from slow-moving material are observed at any phase. We derive physical properties including the bolometric luminosity, and find slow velocity evolution and non-monotonic temperature and radial evolution. A deep radio limit rules out a healthy off-axis gamma-ray burst, and places constraints on the pre-explosion mass loss. The data can be consistently explained by a M stripped progenitor exploding with erg kinetic energy, forming a magnetar with a spin-down timescale of ∼20 days (thus avoiding a gamma-ray burst) that reheats the ejecta and drives ionization fronts. The most likely alternative scenario-interaction with ∼20 M of dense, inhomogeneous circumstellar material-can be tested with continuing radio follow-up.
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