Galactic Wind in the Nearby Starburst Galaxy NGC 253 Observed with the Kyoto3DII Fabry-Perot Mode

We have observed the central region of the nearby starburst galaxy NGC 253 with the Kyoto Tridimensional Spectrograph II (Kyoto3DII) Fabry-Perot mode in order to investigate the properties of its galactic wind. Since this galaxy has a large inclination, it is easy to observe its galactic wind. We produced the Ha, [N II]6583, and [S II]6716,6731 images, as well as those line ratio maps. The [N II]/Ha ratio in the galactic wind region is larger than those in H II regions in the galactic disk. The [N II]/Ha ratio in the southeastern filament, a part of the galactic wind, is the largest and reaches about 1.5. These large [N II]/Ha ratios are explained by shock ionization/excitation. Using the [S II]/Ha ratio map, we spatially separate the galactic wind region from the starburst region. The kinetic energy of the galactic wind can be sufficiently supplied by supernovae in a starburst region in the galactic center. The shape of the galactic wind and the line ratio maps are non-axisymmetric about the galactic minor axis, which is also seen in M82. In the [N II]6583/[S II]6716,6731 map, the positions with large ratios coincide with the positions of star clusters found in the Hubble Space Telescope (HST) observation. This means that intense star formation causes strong nitrogen enrichment in these regions. Our unique data of the line ratio maps including [S II] lines have demonstrated their effectiveness for clearly distinguishing between shocked gas regions and starburst regions, determining the extent of galactic wind and its mass and kinetic energy, and discovering regions with enhanced nitrogen abundance.Comment: 22 pages, 5 figures, 1 table, accepted for publication in Ap

False-positive HIV results and COVID-19 infection or vaccination?

Recently, there have been reports of false-positive HIV results associated with COVID-19 infections and vaccination, which require attention. The similarity between the spike proteins of HIV and SARS-CoV-2 may lead to cross-reactivity of antibodies, resulting in false-positive results on immunoassay screening tests. This hypothesis presents a serious diagnostic challenge. Patients presenting discordant COVID-19 and HIV results should undergo confirmation of the HIV chemiluminescent immunoassay due to the potential for analytical errors. It is essential to highlight the potential for false-positive HIV results related to SARS-CoV-2

1-1.4 Micron Spectral Atlas of Stars

We present a catalog of J-band (1.08 um to 1.35 um) stellar spectra at low resolution (R ~ 400). The targets consist of 105 stars ranging in spectral type from O9.5 to M7 and luminosity classes I through V. The relatively featureless spectra of hot stars, earlier than A4, can be used to remove the atmospheric features which dominate ground-based J-band spectroscopy. We measure equivalent widths for three absorption lines and nine blended features which we identify in the spectra. Using detailed comparison with higher resolution spectra, we demonstrate that low resolution data can be used for stellar classification, since several features depend on the effective temperature and gravity. For example The CN index (1.096 - 1.104 um) decreases with temperature, but the strength of a blended feature at 1.28 um (consisting of primarily P beta) increases. The slope of a star's spectrum can also be used to estimate its effective temperature. The luminosity class of a star correlates with the ratio of the Mg I (1.1831 um) line to a blend of several species at 1.16 um. Using these indicators, a star can be classified to within several subclasses. Fifteen stars with particularly high and low metal abundances are included in the catalog and some spectral dependence on metal abundance is also found.Comment: 35 pages, 10 figures (3a-e are in gif format. For complete high resolution figures, go to http://www.astro.ucla.edu/~malkan/newjspec/) ; Accepted for published in ApJS; For associated spectra files, see http://www.astro.ucla.edu/~malkan/newjspec

Определение содержания 238U по гамма-излучению 234mPa

Radionuclide 238U is one of the most important radioactive elements that must be controlled in nuclear power engineering, geological exploration, control of radioactive contamination of soils and raw materials used in construction. The most optimal way to control 238U is to use the 234mPa radionuclide, the activity of which, due to its short lifetime (≈ 1.2 min), is unambiguously related to the activity of 238U even if the secular equilibrium is disturbed in the sample under studyРossibility of use of the 234mPa nuclide gamma radiation to determine 238U with a scintillation detector in a medium containing natural radionuclides is investigated and demonstrated using the simplest examples. The proposed algorithm for determining of the 238U content is based on the Monte Carlo simulation of the detector response to the radiation of the 234mPa radionuclide at its 1001 keV energy line and subsequent processing of the experimental spectrum, including the Wiener filtering of the signal. This method makes it possible to determine the content of 238U in a continuous homogeneous medium while presence of natural radionuclides in it.The algorithm for determining of 238U content includes several main steps. Filtering based on the Wiener algorithm allows selecting a slowly changing part of the spectrum. Results of Monte Carlo simulations make it possible to determine the detection efficiency in a limited informative region of the spectrum, which includes, along with the 1001 keV peak from the 234mPa nuclide, which is a decay product of the radionuclide 234Th, and the peak of an interfering radionuclide from the decay chain of 232Th. This part of the spectrum does not contain any other lines of gamma radiation from natural radionuclides – decay products of both thorium and uranium chains. These two peaks in the spectral region under study can be separated from each other in a medium with a typical concentration of 234Th.Analysis of results of the activity of depleted uranium metal measuring in accordance with the proposed algorithm shows the possibility of determining of 238U content with an uncertainty of 3–5 %.В атомной энергетике, в геологоразведке, при контроле радиоактивного загрязнения почв и сырья, используемого при строительстве, одним из важнейших радиоактивных элементов, который необходимо контролировать, является 238U. Наиболее оптимально для контроля 238U использовать радионуклид 234mPa, активность которого из-за малости времени его жизни (≈ 1,2 мин) однозначно связана с активностью 238U даже при условии нарушения векового равновесия в исследуемом образце. Исследована и продемонстрирована на простейших примерах возможность использования гамма-излучения нуклида 234mPa для определения 238U с помощью сцинтилляционного детектора в среде, содержащей естественные радионуклиды. Предложенный алгоритм определения содержания 238U основан на моделировании методом Монте-Карло отклика детектора на излучение радионуклида 234mPa на его монолинии 1001 кэВ и последующей обработке экспериментального спектра прибора, включающей винеровскую фильтрацию сигнала. Этот способ позволяет определить содержание 238U в сплошной однородной среде при наличии в ней естественных радионуклидов. Алгоритм определения содержания радионуклида включает в себя несколько основных этапов.Фильтрация на основе алгоритма Винера позволяет выделить медленно меняющуюся часть спектра. Результаты Монте-Карло моделирования дают возможность определить эффективность регистрации в ограниченном информативном участке спектра, включающем наряду с пиком 1001 кэВ от нуклида 234mPa, являющегося продуктом распада радионуклида 234Th, и ближайший к нему пик мешающего радионуклида из цепочки распада 232Th. Этот участок спектра по определению не содержит никаких других линии гамма-излучения от естественных радионуклидов – продуктов распада как ториевой, так и урановых цепочек. Указанные два пика на исследуемом участке спектра могут быть отделены друг от друга в среде с типичной концентрацией 234Th.Анализ результатов измерения активности обеднённого металлического урана в соответствии с предложенным алгоритмом показывает возможность определения содержания 238U с погрешностью 3–5 %

Ionization Source of a Minor-axis Cloud in the Outer Halo of M82

The M82 `cap' is a gas cloud at a projected radius of 11.6 kpc along the minor axis of this well known superwind source. The cap has been detected in optical line emission and X-ray emission and therefore provides an important probe of the wind energetics. In order to investigate the ionization source of the cap, we observed it with the Kyoto3DII Fabry-Perot instrument mounted on the Subaru Telescope. Deep continuum, Ha, [NII]6583/Ha, and [SII]6716,6731/Ha maps were obtained with sub-arcsecond resolution. The superior spatial resolution compared to earlier studies reveals a number of bright Ha emitting clouds within the cap. The emission line widths (< 100 km s^-1 FWHM) and line ratios in the newly identified knots are most reasonably explained by slow to moderate shocks velocities (v_shock = 40--80 km s^-1) driven by a fast wind into dense clouds. The momentum input from the M82 nuclear starburst region is enough to produce the observed shock. Consequently, earlier claims of photoionization by the central starburst are ruled out because they cannot explain the observed fluxes of the densest knots unless the UV escape fraction is very high (f_esc > 60%), i.e., an order of magnitude higher than observed in dwarf galaxies to date. Using these results, we discuss the evolutionary history of the M82 superwind. Future UV/X-ray surveys are expected to confirm that the temperature of the gas is consistent with our moderate shock model.Comment: 7 pages, 5 figures, 2 tables; Accepted for publication in Ap

Relation between the superconducting gap energy and the two-magnon Raman peak energy in Bi2Sr2Ca{1-x}YxCu2O{8+\delta}

The relation between the electronic excitation and the magnetic excitation for the superconductivity in Bi2Sr2Ca{1-x}YxCu2O{8+\delta} was investigated by wide-energy Raman spectroscopy. In the underdoping region the B1g scattering intensity is depleted below the two-magnon peak energy due to the "hot spots" effects. The depleted region decreases according to the decrease of the two-magnon peak energy, as the carrier concentration ncreases. This two-magnon peak energy also determines the B1g superconducting gap energy as $2\Delta \approx \alpha \hbar \omega_{\rm Two-Magnon} \approx J_{\rm effective}$ $(\alpha=0.34-0.41)$ from under to overdoping hole concentration.Comment: 10 pages, 4 figure