Статті в журналах: "Line ratio diagnostics"

1

Dwivedi, B. N. "Si VII line ratio diagnostics for CDS." Solar Physics 165, no. 2 (May 1996): 399–402. http://dx.doi.org/10.1007/bf00149722.

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2

Keenan, F. P. "Line Ratio Diagnostics Applicable to Astronomical Spectra in the 50–3000 Å Wavelength Region." International Astronomical Union Colloquium 152 (1996): 595–96. http://dx.doi.org/10.1017/s0252921100036599.

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A bibliography has been produced of the most reliable emission and absorption line ratio diagnostic calculations currently available for application to the spectra of astrophysical sources in the UV and EUV wavelength region (50-3000 Å). References are listed containing diagnostics for species in the Li through P isoelectronic sequences, as well as the iron ions Fe II-Fe XXIII and nickel ions Ni XVII-Ni XXV. Also given is the wavelength range for which diagnostic calculations are presented in each reference, along with the type of diagnostic considered. These include, for example, emission line ratios for determining electron temperatures and densities, and absorption line diagnostics for evaluating hydrogen densities.

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3

Murakami, Izumi, and Takako Kato. "Electron temperature diagnostics by Fe XXIII line intensity ratio." Fusion Engineering and Design 34-35 (March 1997): 751–54. http://dx.doi.org/10.1016/s0920-3796(96)00550-9.

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4

Masai, Kuniaki, and Takako Kato. "Electron density diagnostics by Fe XXII line intensity ratio." Physics Letters A 123, no. 8 (August 1987): 405–9. http://dx.doi.org/10.1016/0375-9601(87)90042-9.

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5

Phillips, K. J. H., J. Dubau, J. Sylwester, B. Sylwester, J. L. Culhane, G. A. Doschek, and J. Lang. "Temperature-sensitive line ratio diagnostics based on Si satellite-to-resonance line ratios for 1s2–1snp transitions." Advances in Space Research 38, no. 7 (January 2006): 1543–46. http://dx.doi.org/10.1016/j.asr.2005.08.025.

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6

Boivin, R. F., S. D. Loch, C. P. Ballance, D. Branscomb, and M. S. Pindzola. "Line ratio diagnostics in helium and helium seeded argon plasmas." Plasma Sources Science and Technology 16, no. 3 (May 14, 2007): 470–79. http://dx.doi.org/10.1088/0963-0252/16/3/006.

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7

Keenan, F. P., P. J. Crockett, K. M. Aggarwal, D. B. Jess, and M. Mathioudakis. "Ultraviolet and extreme-ultraviolet line ratio diagnostics for O IV." Astronomy & Astrophysics 495, no. 1 (January 14, 2009): 359–62. http://dx.doi.org/10.1051/0004-6361:200811222.

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8

McKENZIE, D. L. "X-RAY LINE-RATIO PLASMA DIAGNOSTICS APPLIED TO SOLAR ACTIVE REGIONS." Le Journal de Physique Colloques 49, no. C1 (March 1988): C1–55—C1–58. http://dx.doi.org/10.1051/jphyscol:1988109.

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9

Mckenzie, D. L. "X-Ray Line-Ratio Plasma Diagnostics Applied to Solar Active Regions." International Astronomical Union Colloquium 102 (1988): 55–58. http://dx.doi.org/10.1017/s0252921100107407.

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10

Zhen, Zhiqiang, and Jian He. "Opacity of Krypton X-ray lines in high-temperature plasma implosion." Modern Physics Letters B 33, no. 33 (November 30, 2019): 1950418. http://dx.doi.org/10.1142/s0217984919504189.

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For accurate electron temperature and density diagnostics in laser high-temperature plasma implosion, opacity of Krypton (Kr) helium-[Formula: see text] and Balmer-[Formula: see text] lines are discussed, and ratio of escape factor of the two X-rays are calculated, both for Gaussian and Holtzmarkian profiles. Finally, the line ratios of the two X-ray lines are analyzed for optically thin and thick plasmas. Results indicate that for the Gaussian profile, the line ratio varies greatly with the opacity of the Kr helium-[Formula: see text] line, which provides excellent source for temperature and electron density diagnostics; while for the Holtzmarkian profile, the line ratio varies less with the opacity of the Kr helium-[Formula: see text] line, which can be used for escape factor diagnostics. This method is significant in accurate plasma diagnostics using X-rays under the condition of optically thick.

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11

Dwivedi, B. N. "EUV Line Diagnostics for CDS and Sumer on SOHO." International Astronomical Union Colloquium 144 (1994): 625–30. http://dx.doi.org/10.1017/s025292110002618x.

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AbstractThe EUV line diagnostics for the CDS and the SUMER instruments, to be flown onboard the SOHO mission, are discussed. Serts observations of EUV line intensities in an active region, reported by Thomas and Neupert (1993), have been used to determine the electron density and temperature from a theoretical curve of Mg VIII density-sensitive line ratio.

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12

Olluri, K., B. V. Gudiksen, and V. H. Hansteen. "NON-EQUILIBRIUM IONIZATION EFFECTS ON THE DENSITY LINE RATIO DIAGNOSTICS OF O IV." Astrophysical Journal 767, no. 1 (March 22, 2013): 43. http://dx.doi.org/10.1088/0004-637x/767/1/43.

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13

Dwivedi, B. N., Anita Mohan, and P. K. Raju. "On the line ratio diagnostics for NeV, MgV, SiVII and MgVII solar ions." Advances in Space Research 20, no. 12 (January 1997): 2271–74. http://dx.doi.org/10.1016/s0273-1177(97)00900-9.

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14

Charatis, G., G. E. Busch, B. K. F. Young, and R. E. Stewart. "Diagnostic Characterization of Laser-Irradiated dot Targets." International Astronomical Union Colloquium 102 (1988): 375–78. http://dx.doi.org/10.1017/s0252921100108139.

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AbstractWe have conducted a series of experiments at the KMS CHROMA facility using dot spectroscopy techniques to characterize uncertainties associated with spectral line ratio models commonly applied in determining electron temperatures and densities. Temperatures determined from the slope of the H-like free-bound continuum and densities via holographic interferometry, are compared to line ratio methods. Dot targets of (typically 100µmD Mg or Al) are irradiated with 2 to 40 × 1013W/cm2of 0.53µmlight. Time and spatial gradients are resolved using 4 diagnostics: a 4-frame holographic interferometer, an x-ray streak crystal spectrograph with a spatial imaging slit, a framing crystal x-ray spectrometer, and a conventional space-resolved time-integrating crystal spectrograph used for survey and calibration purposes. Preliminary results indicate the ionization distribution of these laser produced plasmas is not steady-state which plays an important role in measuring the temperature and and density. Electron temperatures derived from line-ratio techniques, assuming steady state conditions, disagree dramatically from simultaneous measurements using the slope of the H-like continuum. Electron densities using He-like triplet to singlet line ratios also differ from densities measured interferometrically.

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15

Kambara, Nagaaki, Tomoko Kawate, Tetsutarou Oishi, Yasuko Kawamoto, Hiroyuki A. Sakaue, Daiji Kato, Nobuyuki Nakamura, Hirohisa Hara, and Izumi Murakami. "Evaluation of Fe XIV Intensity Ratio for Electron Density Diagnostics by Laboratory Measurements." Atoms 9, no. 3 (August 30, 2021): 60. http://dx.doi.org/10.3390/atoms9030060.

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The intensity ratio of Fe XIV 264.765A/274.203A is useful to determine the electron density of solar corona, and the relationship between the electron density and the intensity ratio obtained from a model should be evaluated using laboratory plasmas to estimate the electron density more precisely. We constructed a new collisional–radiative model (CR-model) for Fe XIV (an Al-like iron ion) by considering the processes of proton-impact excitation and electron-impact ionization to the excited states of a Mg-like iron ion. The atomic data used in the CR-model were calculated using the HULLAC atomic code. The model was evaluated based on laboratory experiments using a compact electron beam ion trap, called CoBIT, and the Large Helical Device (LHD). The measured Fe XIV 264.785 Å/274.203 Å line intensity ratio with CoBIT was 1.869 ± 0.036, and it agreed well with our CR-model results. Concurrently, the measured ratio using LHD was larger than the results of our CR-model and CHIANTI. The estimated electron densities using our CR-model agreed with those from CHIANTI within a factor of 1.6–2.4 in the range of ne≈1010−11cm−3. Further model development is needed to explain the ratio in a high-electron density region.

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16

Ono, Toshisato, Shreyashi Ganguly, Qiaomiao Tu, Uwe R. Kortshagen, and Eray S. Aydil. "Plasma diagnostics and modeling of lithium-containing plasmas." Journal of Physics D: Applied Physics 55, no. 25 (March 29, 2022): 254001. http://dx.doi.org/10.1088/1361-6463/ac5c1d.

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Abstract Thin-film deposition from chemically reactive multi-component plasmas is complex, and the lack of electron collision cross-sections for even the most common metalorganic precursors and their fragments complicates their modeling based on fundamental plasma physics. This study focuses on understanding the plasma physics and chemistry in argon (Ar) plasmas containing lithium bis (trimethylsilyl) amide used to deposit Li x Si y thin films. These films are emerging as potential solid electrolytes for lithium-ion batteries, and the Li-to-Si ratio is a crucial parameter to enhance their ionic conductivity. We deposited Li x Si y films in an axial flow-through plasma reactor and studied the factors that determine the variation of the Li-to-Si ratio in films deposited at various points on a substrate spanning the entire reactor axis. While the Li-to-Si ratio is 1:2 in the precursor, the Li-to-Si ratio is as high as 3:1 in films deposited near the plasma entrance and decreases to 1:1 for films deposited downstream. Optical emission from the plasma is dominated by Li emission near the entrance, but Li emission disappears downstream, which we attribute to the complete consumption of the precursor. We hypothesized that the axially decreasing precursor concentration affects the electron energy distribution function in a way that causes different dissociation efficiencies for the production of Li and Si. We used Li line intensities to estimate the local precursor concentration and Ar line ratios to estimate the local reduced electric field to test this hypothesis. This analysis suggests that the mean electron energy increases along the reactor axis with decreasing precursor concentration. The decreasing Li-to-Si ratio with axially decreasing precursor concentration may be explained by Li release from the precursor having lower threshold energy than Si release.

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17

Pereira-Santaella, M., D. Rigopoulou, D. Farrah, V. Lebouteiller, and J. Li. "Far-infrared metallicity diagnostics: application to local ultraluminous infrared galaxies." Monthly Notices of the Royal Astronomical Society 470, no. 1 (May 24, 2017): 1218–32. http://dx.doi.org/10.1093/mnras/stx1284.

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AbstractThe abundance of metals in galaxies is a key parameter that permits to distinguish between different galaxy formation and evolution models. Most of the metallicity determinations are based on optical line ratios. However, the optical spectral range is subject to dust extinction and, for high-z objects (z > 3), some of the lines used in optical metallicity diagnostics are shifted to wavelengths not accessible to ground-based observatories. For this reason, we explore metallicity diagnostics using far-infrared (far-IR) line ratios which can provide a suitable alternative in such situations. To investigate these far-IR line ratios, we modelled the emission of a starburst with the photoionization code cloudy. The most sensitive far-IR ratios to measure metallicities are the [O iii]52 μm and 88 μm to [N iii]57 μm ratios. We show that this ratio produces robust metallicities in the presence of an active galactic nucleus and is insensitive to changes in the age of the ionizing stellar. Another metallicity-sensitive ratio is the [O iii]88 μm/[N ii]122 μm ratio, although it depends on the ionization parameter. We propose various mid- and far-IR line ratios to break this dependence. Finally, we apply these far-IR diagnostics to a sample of 19 local ultraluminous IR galaxies (ULIRGs) observed with Herschel and Spitzer. We find that the gas-phase metallicity in these local ULIRGs is in the range $0.7<Z_{\rm gas}/$ Z⊙ < 1.5, which corresponds to $8.5 <12 + \log ({\rm O / H}) < 8.9$. The inferred metallicities agree well with previous estimates for local ULIRGs and this confirms that they lie below the local mass–metallicity relation.

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18

Yuk, Heechan, Xinyu Dai, T. Jayasinghe, Hai Fu, Hora D. Mishra, Christopher S. Kochanek, Benjamin J. Shappee, and K. Z. Stanek. "Variability Selected Active Galactic Nuclei from ASAS-SN Survey: Constraining the Low Luminosity AGN Population." Astrophysical Journal 930, no. 2 (May 1, 2022): 110. http://dx.doi.org/10.3847/1538-4357/ac6423.

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Abstract Low luminosity active galactic nuclei (LLAGN) probe accretion physics in the low Eddington regime can provide additional clues about galaxy evolution. AGN variability is ubiquitous and thus provides a reliable tool for finding AGN. We analyze the All-Sky Automated Survey for SuperNovae light curves of 1218 galaxies with g < 14 mag and Sloan Digital Sky Survey spectra in search of AGN. We find 37 objects that are both variable and have AGN-like structure functions, which is about 3% of the sample. The majority of the variability selected AGN are LLAGN with Eddington ratios ranging from 10−4 to 10−2. We thus estimate the fraction of LLAGN in the population of galaxies as 2% down to a median Eddington ratio of 2 × 10−3. Combining the BPT line ratio AGN diagnostics and the broad-line AGN, up to ∼60% of the AGN candidates are confirmed spectroscopically. The BPT diagnostics also classified 10%–30% of the candidates as star-forming galaxies rather than AGN.

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19

Morisset, Christophe, Valentina Luridiana, Jorge García-Rojas, Verónica Gómez-Llanos, Manuel Bautista, and Claudio Mendoza. "Atomic Data Assessment with PyNeb." Atoms 8, no. 4 (October 4, 2020): 66. http://dx.doi.org/10.3390/atoms8040066.

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PyNeb is a Python package widely used to model emission lines in gaseous nebulae. We take advantage of its object-oriented architecture, class methods, and historical atomic database to structure a practical environment for atomic data assessment. Our aim is to reduce the uncertainties in the parameter space (line ratio diagnostics, electron density and temperature, and ionic abundances) arising from the underlying atomic data by critically selecting the PyNeb default datasets. We evaluate the questioned radiative-rate accuracy of the collisionally excited forbidden lines of the N- and P-like ions (O ii, Ne iv, S ii, Cl iii, and Ar iv), which are used as density diagnostics. With the aid of observed line ratios in the dense NGC 7027 planetary nebula and careful data analysis, we arrive at emissivity ratio uncertainties from the radiative rates within 10%, a considerable improvement over a previously predicted 50%. We also examine the accuracy of an extensive dataset of electron-impact effective collision strengths for the carbon isoelectronic sequence recently published. By estimating the impact of the new data on the pivotal [N ii] and [O iii] temperature diagnostics and by benchmarking the collision strength with a measured resonance position, we question their usefulness in nebular modeling. We confirm that the effective-collision-strength scatter of selected datasets for these two ions does not lead to uncertainties in the temperature diagnostics larger than 10%.

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20

Topal, Selçuk. "Molecular line ratio diagnostics and gas kinematics in the AGN host Seyfert galaxy NGC 5033." Monthly Notices of the Royal Astronomical Society 504, no. 4 (May 6, 2021): 5941–53. http://dx.doi.org/10.1093/mnras/stab1269.

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ABSTRACT Multiple molecular lines are useful for studying the physical properties of multiphase star-forming gas in different types of galaxies. We probe the molecular gas throughout the disc of the spiral galaxy NGC 5033, hosting an active galactic nucleus (AGN), using multiple low-J CO lines [12CO(1–0, 2–1, 3–2 and 13CO(1–0, 2–1)] and dense gas tracers [HCN(1–0) and HCO+(1–0)]. First, we determine the ratios of the integrated intensity maps and the ratio of intensities in position velocity diagrams. Secondly, we obtain the ratios of CO lines and high-density tracers at the centre; and thirdly, we model these line ratios using a radiative transfer code. Line ratio diagnostics reveal that the south of the gaseous disc contains cooler gas than the northern part, and the centre hosts warmer and less tenuous gas with a similar dense gas fraction compared to most galaxies of similar type. Our model results mostly agree with the empirical ones in the sense that the central region of NGC 5033 harbours warmer gas than that in the centres of normal spirals and lenticulars without showing AGN activity. Finally, the beam-averaged total molecular gas mass and gas surface density along the galaxy’s major axis show a radial gradient, i.e. increasing from the outskirts up to the central region of size 1 kpc where there is a depression in both gas mass and surface density.

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21

Deutsch, C., H. B. Nersisyan, and A. Bendib. "Diagnosing dense and magnetized plasmas irradiated by a petawatt laser." Laser and Particle Beams 34, no. 1 (November 30, 2015): 61–71. http://dx.doi.org/10.1017/s0263034615000919.

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AbstractWe survey the present status and potentialities of diagnostics for arbitrary magnetized plasmas of inertial confinement fusion concern. These diagnostics include: Faraday rotation, inverse Faraday effect, Thomson scattering, Stark–Zeeman line broadening as well as proton stopping for any ratio, of the particles plasma frequency to cyclotron frequency. This presentation is timely motivated by recent experiments highlighting laser-produced kilo Teslas and nearly steady magnetic fields in inertial fusion plasmas. Positive synergies due to diagnostics combinations are also addressed.

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22

Kopsacheili, M., A. Zezas, and I. Leonidaki. "A diagnostic tool for the identification of supernova remnants." Monthly Notices of the Royal Astronomical Society 491, no. 1 (November 23, 2019): 889–902. http://dx.doi.org/10.1093/mnras/stz2594.

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ABSTRACT We present new diagnostic tools for distinguishing supernova remnants (SNRs) from H ii regions. Up to now, sources with flux ratio [S ii]/H$\rm {\alpha }$ higher than 0.4 have been considered as SNRs. Here, we present combinations of three or two line ratios as more effective tools for the separation of these two kinds of nebulae, depicting them as 3D surfaces or 2D lines. The diagnostics are based on photoionization and shock-excitation models (mappings iii) analysed with support vector machine (SVM) models for classification. The line-ratio combination that gives the most efficient diagnostic is [O i]/H$\rm {\alpha }$ – [O ii]/H$\rm {\beta }$ – [O iii]/H$\rm {\beta }$. This method gives $98.95{{\ \rm per\ cent}}$ completeness in the SNR selection and $1.20{{\ \rm per\ cent}}$ contamination. We also define the [O i]/H$\rm {\alpha }$ SNR selection criterion and measure its efficiency in comparison with other selection criteria.

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23

Canizares, Claude R. "High Resolution Spectroscopy and Plasma Diagnostics of Supernova Remnants." International Astronomical Union Colloquium 115 (1990): 136–45. http://dx.doi.org/10.1017/s0252921100012240.

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AbstractThe MIT group has used data from the Focal Plane Crystal Spectrometer on the Einstein Observatory to perform plasma diagnostics of four supernova remnants (SNRs), the Cygnus Loop, Puppis A, N132D, and Cas A. The ratio of luminosities of the forbidden line to resonance line of He-like ions of oxygen and neon allow us to show that all four SNRs depart from ionization equilibrium in that they are under-ionized for their electron temperatures. Thus despite the fact that their ages range from 300 yr to 20,000 yr, all four SNRs are still ionizing and, in that sense, are still young. We derive values of ionization time and electron temperature for one or more components in each remnant. The agreement between these values and those deduced by others using entirely different means (e.g. broad-band spectroscopy or imaging) gives us confidence in the reliability of the diagnostics. Two of the SNRs, Puppis A and N132D, show evidence for an overabundance of oxygen by factors of three or more. These results, based on a handful of weak lines, show the great promise of the much more powerful future spectroscopy missions for revealing detailed information about astrophysical plasmas.

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24

Träbert, Elmar, Peter Beiersdorfer, Gregory V. Brown, Natalie Hell, Jaan K. Lepson, Alexander J. Fairchild, Michael Hahn, and Daniel W. Savin. "Laboratory Search for Fe IX Solar Diagnostic Lines Using an Electron Beam Ion Trap." Atoms 10, no. 4 (October 16, 2022): 115. http://dx.doi.org/10.3390/atoms10040115.

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The Fe IX spectrum features two lines in the extreme ultraviolet whose ratio has been rated among the best density diagnostics in the solar spectrum. One line is an E1-allowed intercombination transition at 244.909 Å, the other an E1-forbidden M2 transition at 241.739 Å. Employing a medium and a high resolution spectrometer at the Livermore EBIT-I electron beam ion trap, we have observed the line pair in the laboratory for the first time. Using a CHIANTI model computation, the observed line ratio yields a value of the electron density that is compatible with typical densities in our device.

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25

Koubiti, Mohammed, and Roshin Sheeba. "Spectral Modeling of Hydrogen Radiation Emission in Magnetic Fusion Plasmas." Atoms 7, no. 1 (February 12, 2019): 23. http://dx.doi.org/10.3390/atoms7010023.

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Modeling of the spectral line and continuum radiation emitted by hydrogen isotopes in peripheral regions of magnetic fusion is presented through profiles of the Zeeman-Doppler broadened Hα/Dα line and those of the Stark broadened high-n Balmer lines extending beyond the series limit for recombining plasmas. The Hα/Dα line profiles should be modelled while accounting for several populations of neutrals to mimic real situations and analyze experimental data for isotopic ratio determination. On the other side, high-n Balmer lines of hydrogen are used for plasma electron density and temperature diagnostics. Moreover, modelling whole spectra including the continuum radiation contributes to the development of synthetic diagnostics for future magnetic fusion devices for which they can give predictive results through coupling to numerical simulation tools.

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26

Madjarska, M. S., J. C. Vial, K. Bocchialini, and V. N. Dermendjiev. "Plasma Parameters of a Prominence Observed on October 16/17 1999 by SUMER and CDS/SOHO." Symposium - International Astronomical Union 203 (2001): 410–12. http://dx.doi.org/10.1017/s0074180900219669.

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The aim of the present study is to confirm and enrich the results obtained so far on dynamics and diagnostics of solar prominences. A prominence observed on October 16/17, 1999 in the frame of the updated JOP09 was studied. A density diagnostics was made on the basis of the line intensity ratio O IV 1401/1404. The Doppler velocities were derived using SUMER Si IV, O IV and CDS O V 629.73 Å lines.

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27

Fantoni, R., M. Giorgi, A. G. G. Moliterni, W. C. M. Berden, V. Lazic, O. Martini, and F. Polla Mattiot. "On-line gas-phase optical diagnostics in plasma CVD deposition of carbon films." Journal of Materials Research 7, no. 5 (May 1992): 1204–14. http://dx.doi.org/10.1557/jmr.1992.1204.

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Space resolved, on-line spontaneous and stimulated emission, and CARS diagnostics have been employed on CH4/H2 mixtures excited by rf-discharge in order to investigate the chemical processes and the gas phase kinetics in the plasma. CH4 and H2 concentration and temperature have been monitored during the process as a function of main reaction parameters (rf-power, total pressure, CH4/H2 ratio). Formation of CH,H2, and H in excited states has been observed. On the basis of present spectroscopic data, a model for the gas-phase reactions accompanying the carbon film deposition is proposed.

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28

Dudík, Jaroslav, Elena Dzifčáková, Giulio Del Zanna, Helen E. Mason, Leon L. Golub, Amy R. Winebarger та Sabrina L. Savage. "Signatures of the non-Maxwellian κ-distributions in optically thin line spectra". Astronomy & Astrophysics 626 (червень 2019): A88. http://dx.doi.org/10.1051/0004-6361/201935285.

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Aims. We investigated the possibility of diagnosing the degree of departure from the Maxwellian distribution using the Fe XVII–Fe XVIII spectra originating in plasmas in collisional ionization equilibrium, such as in the cores of solar active regions or microflares. Methods. The original collision strengths for excitation are integrated over the non-Maxwellian electron κ-distributions characterized by a high-energy tail. Synthetic X-ray emission line spectra were calculated for a range of temperatures and κ. We focus on the 6–24 Å spectral range to be observed by the upcoming Marshall Grazing-Incidence X-ray Spectrometer MaGIXS. Results. We find that many line intensity ratios are sensitive to both T and κ. Best diagnostic options are provided if a ratio involving both Fe XVII and Fe XVIII is combined with another ratio involving lines formed within a single ion. The sensitivity of such diagnostics to κ is typically a few tens of per cent. Much larger sensitivity, of about a factor of two to three, can be obtained if the Fe XVIII 93.93 Å line observed by SDO/AIA is used in conjuction with the X-ray lines. Conclusions. We conclude that the MaGIXS instrument is well-suited for detection of departures from the Maxwellian distribution, especially in active region cores.

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29

Yin, Charles, Felix D. Priestley, and James Wurster. "Investigating the role of magnetic fields in star formation using molecular line profiles." Monthly Notices of the Royal Astronomical Society 504, no. 2 (April 20, 2021): 2381–89. http://dx.doi.org/10.1093/mnras/stab1039.

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ABSTRACT Determining the importance of magnetic fields in star-forming environments is hampered by the difficulty of accurately measuring both field strength and gas properties in molecular clouds. We post-process three-dimensional non-ideal magnetohydrodynamic simulations of pre-stellar cores with a time-dependent chemical network, and use radiative transfer modelling to calculate self-consistent molecular line profiles. Varying the initial mass-to-flux ratio from subcritical to supercritical results in significant changes to both the intensity and shape of several observationally important molecular lines. We identify the peak intensity ratio of N2H+ to CS lines, and the CS J = 2–1 blue-to-red peak intensity ratio, as promising diagnostics of the initial mass-to-flux ratio, with N2H+/CS values of >0.6 (<0.2) and CS blue/red values of <3 (>5) indicating subcritical (supercritical) collapse. These criteria suggest that, despite presently being magnetically supercritical, L1498 formed from subcritical initial conditions.

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30

Tonarely, Michael E., Tommy Genova, Anthony J. Morales, Daniel Micka, Darin Knaus, and Kareem A. Ahmed. "Four-Line C2*/CH* Optical Sensor for Chemiluminescence Based Imaging of Flame Stoichiometry." Sensors 22, no. 15 (July 28, 2022): 5665. http://dx.doi.org/10.3390/s22155665.

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In the present work, an optical sensor was developed and calibrated for the purpose of non-intrusive equivalence ratio measurements in combustion systems. The sensor incorporates a unique four-line, single-sensor chemiluminescence imaging-based approach, which relies on the ratio of C2* and CH* radical-species intensities to obtain measurements of equivalence ratios. The advantage of the four-line sensor is the use of additional filtering to mitigate broadband luminescence signals, and its improvements over conventional two-line chemiluminescence diagnostics are discussed. The sensor was calibrated using a premixed bluff-body jet burner with a propane–air flame operating over a wide range of equivalence ratios. The results showed that the four-line processing technique improved the signal-to-noise ratio of the chemiluminescence images for all test cases. Calibrations of C2*/CH* intensity ratio to equivalence ratio were developed for both the four-line and two-line techniques. The calibrations were then used to create maps of local equivalence ratios in the flame-holding region. The maps revealed a non-uniform field of equivalence ratios due to the nature of the radical-species intensity profiles within the flame. Therefore, special consideration is required for calibration in order to accurately quantify equivalence ratios and apply these to diffusion flames.

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31

Li, Yaran, Wenjie Li, Liang Chen, Huanzhen Ma, Xinye Xu, Jie Xu, Xin Wang, and Baozhong Mu. "Basic principles and optical system design of 17.48 keV high-throughput modified Wolter x-ray microscope." Review of Scientific Instruments 93, no. 9 (September 1, 2022): 093526. http://dx.doi.org/10.1063/5.0105015.

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High-precision x-ray imaging diagnostics of hotspot at the stagnation stage are essential for regulating implosion asymmetry and retrieving physical implosion parameters. With regard to 10–20 keV energy band imaging, existing diagnostic instruments such as Kirkpatrick–Baez microscopes and pinhole cameras are insufficient in terms of spatial resolution and collection efficiency. The situation is even worse when high-speed, time-resolved imaging diagnostics are performed by coupling framing cameras or line-of-sight imagers. This article presents the basic principles and optical system design of a 17.48 keV modified Wolter x-ray microscope, to resolve the problems encountered in high-energy imaging diagnostics. The proposed optical configuration offers a better spatial resolution, greater depth of field, and preliminary compliance with the requirements of high precision optical processing techniques. The spatial resolution is better than 1 µm in a field range ±150 µm, and is better than 3 µm in a total field of view ∼408 µm in diameter. The geometric solid angle is calculated as 3.0 × 10−5 sr and is estimated to be 1.2 × 10−6 sr, considering the reflectivity of the double mirrors. The proposed microscope is expected to effectively improve spatial resolution and signal-to-noise ratio for high-energy imaging diagnostics.

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32

Keenan, F. P. "The ratio of optical to near-infrared emission line strengths inSii as electron density diagnostics for planetary nebulae." Astrophysics and Space Science 186, no. 2 (December 1991): 277–81. http://dx.doi.org/10.1007/bf02111201.

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33

Oh, Kyuseok, Michael J. Koss, Yoshihiro Ueda, Daniel Stern, Claudio Ricci, Benny Trakhtenbrot, Meredith C. Powell, et al. "BASS. XXIV. The BASS DR2 Spectroscopic Line Measurements and AGN Demographics." Astrophysical Journal Supplement Series 261, no. 1 (July 1, 2022): 4. http://dx.doi.org/10.3847/1538-4365/ac5b68.

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Abstract We present the second catalog and data release of optical spectral line measurements and active galactic nucleus (AGN) demographics of the BAT AGN Spectroscopic Survey, which focuses on the Swift-BAT hard X-ray detected AGNs. We use spectra from dedicated campaigns and publicly available archives to investigate spectral properties of most of the AGNs listed in the 70 month Swift-BAT all-sky catalog; specifically, 743 of the 746 unbeamed and unlensed AGNs (99.6%). We find a good correspondence between the optical emission line widths and the hydrogen column density distributions using the X-ray spectra, with a clear dichotomy of AGN types for N H = 1022 cm−2. Based on optical emission-line diagnostics, we show that 48%–75% of BAT AGNs are classified as Seyfert, depending on the choice of emission lines used in the diagnostics. The fraction of objects with upper limits on line emission varies from 6% to 20%. Roughly 4% of the BAT AGNs have lines too weak to be placed on the most commonly used diagnostic diagram, [O iii]λ5007/Hβ versus [N ii]λ6584/Hα, despite the high signal-to-noise ratio of their spectra. This value increases to 35% in the [O iii]λ5007/[O ii]λ3727 diagram, owing to difficulties in line detection. Compared to optically selected narrow-line AGNs in the Sloan Digital Sky Survey, the BAT narrow-line AGNs have a higher rate of reddening/extinction, with Hα/Hβ > 5 (∼36%), indicating that hard X-ray selection more effectively detects obscured AGNs from the underlying AGN population. Finally, we present a subpopulation of AGNs that feature complex broad lines (34%, 250/743) or double-peaked narrow emission lines (2%, 17/743).

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34

Wehrmeyer, Joseph A., David E. Boll, and Richard Smith. "Emission Spectroscopy for Coal-Fired Cyclone Furnace Diagnostics." Applied Spectroscopy 57, no. 8 (August 2003): 1020–26. http://dx.doi.org/10.1366/000370203322258995.

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Using a spectrograph and charge-coupled device (CCD) camera, ultraviolet and visible light emission spectra were obtained from a coal-burning electric utility's cyclone furnaces operating at either fuel-rich or fuel-lean conditions. The aim of this effort is to identify light emission signals that can be related to a cyclone furnace's operating condition in order to adjust its air/fuel ratio to minimize pollutant production. Emission spectra at the burner and outlet ends of cyclone furnaces were obtained. Spectra from all cyclone burners show emission lines for the trace elements Li, Na, K, and Rb, as well as the molecular species OH and CaOH. The Ca emission line is detected at the burner end of both the fuel-rich and fuel-lean cyclone furnaces but is not detected at the outlet ends of either furnace type. Along with the disappearance of Ca is a concomitant increase in the CaOH signal at the outlet end of both types of furnaces. The OH signal strength is in general stronger when viewing at the burner end rather than the exhaust end of both the fuel-rich and fuel-lean cyclone furnaces, probably due to high, non-equilibrium amounts of OH present inside the furnace. Only one molecular species was detected that could be used as a measure of air/fuel ratio: MgOH. It was detected at the burner end of fuel-rich cyclone furnaces but not detected in fuel-lean cyclone furnaces. More direct markers of air/fuel ratio, such as CO and O2 emission, were not detected, probably due to the generally weak nature of molecular emission relative to ambient blackbody emission present in the cyclone furnaces, even at ultraviolet wavelengths.

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35

Keenan, F. P., J. J. Drake, V. J. Foster, C. J. Greer, S. S. Tayal, and K. G. Widing. "Fe XIII Emission Lines Observed by EUVE and the S082A Instrument On-Board Skylab." International Astronomical Union Colloquium 152 (1996): 525–29. http://dx.doi.org/10.1017/s0252921100036496.

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Recent R-matrix calculations of electron impact excitation rates for Fe XIII are used to derive the theoretical electron density sensitive emission line ratios R1 = I(318.12 Å)/I(320.80 Å) and R2 = I(256.42 Å)/I(251.95 Å), which are found to be up to 50% different from earlier diagnostics. A comparison of the current line ratios with both solar flare and active region observations, obtained by the Naval Research Laboratory’s S082A spectrograph on board Skylab, reveals generally good agreement between densities deduced from Fe XIII and those estimated from diagnostic line ratios in species formed at similar temperatures. This provides experimental support for the accuracy of the line ratio calculations, and hence the atomic data adopted in their derivation. In Extreme Ultraviolet Explorer satellite (EUVE) spectra the Fe XIII emission lines are found to be severely blended. However, an analysis of these lines measured in the spectra of Procyon and α Cen demonstrates that they still allow very approximate values of the electron density to be inferred. Moreover, it should be possible to increase the accuracy of the measured line fluxes, and hence of the inferred densities, if longer exposures of the stars concerned can be obtained.

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36

Topal, Selçuk. "Molecular line ratio diagnostics along the radial cut and dusty ultraviolet-bright clumps in a spiral galaxy NGC 0628." Monthly Notices of the Royal Astronomical Society 495, no. 3 (January 2020): 2682–712. http://dx.doi.org/10.1093/mnras/staa1146.

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ABSTRACT Molecular emission lines are essential tools to shed light on many questions regarding star formation in galaxies. Multiple molecular lines are particularly useful to probe different phases of star-forming molecular clouds. In this study, we investigate the physical properties of giant molecular clouds (GMCs) using multiple lines of CO, i.e. CO(1–0, 2–1, 3–2) and 13CO(1–0), obtained at selected 20 positions in the disc of NGC 0628. A total of 11 positions were selected over the radial cut, including the centre, and remaining 9 positions were selected across the southern and northern arms of the galaxy. A total of 13 out of 20 positions are brighter at $24\, \mu {\rm m}$ and ultraviolet (UV) emission and hosting significantly more H ii regions compared to the rest of the positions indicating opposite characteristics. Our line ratio analysis shows that the gas gets warmer and thinner as a function of radius from the galaxy centre up to 1.7 kpc, and then the ratios start to fluctuate. Our empirical and model results suggest that the UV-bright positions have colder and thinner CO gas with higher hydrogen and CO column densities. However, the UV-dim positions have relatively warmer CO gas with lower densities bathed in GMCs surrounded by less number of H ii regions. Analysis of multiwavelength infrared and UV data indicates that the UV-bright positions have higher star formation efficiency than that of the UV-dim positions.

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37

Keenan, F. P., and E. S. Conlon. "The ratio of optical-to-infrared emission line strengths in AR III as electron density diagnostics for planetary nebulae." Astrophysical Journal 410 (June 1993): 426. http://dx.doi.org/10.1086/172759.

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38

Keenan, F. P., and K. M. Aggarwal. "The ratio of optical to infrared emission-line strengths in O III as electron temperature diagnostics for planetary nebulae." Astrophysical Journal 350 (February 1990): 262. http://dx.doi.org/10.1086/168377.

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39

Dwivedi, Bhola N. "X-ray Lines From Mg VIII and Si X Ions and Their Diagnostic Use." International Astronomical Union Colloquium 115 (1990): 40–43. http://dx.doi.org/10.1017/s0252921100012094.

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AbstractThe solar X-ray emission lines from Mg VIII and Si X ions have been studied. The variation of theoretical line intensity ratio I(λ 75.03)/I(λ 74.86) from Mg VIII and I(λ 50.69)/I(λ 50.52) from Si X as a function of electron density is found to be good density monitors of the emitting regions of solar plasma. The computed values of line intensity from these ions based on Kopp and Orrall model have been used to derive electron density of the quiet Sun and coronal holes. The electron densities of 109 cm-3 and 4.6 × 108 cm-3 are estimated at the electron temperatures of 8 x 105 K and 1.6 x 106 K for the quiet Sun whereas the respective values of 5.4 x 108 cm-3 and 1.7 x 108 cm-3 are obtained for the coronal holes. The line intensity ratios studied here are independent of temperature variation and are therefore excellent candidates for electron density diagnostics. However, observational data with improved spectral resolution is needed for using X-ray line pairs studied for their diagnostic use.

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40

Bublitz, J., J. H. Kastner, M. Santander-García, V. Bujarrabal, J. Alcolea, and R. Montez. "A new radio molecular line survey of planetary nebulae." Astronomy & Astrophysics 625 (May 2019): A101. http://dx.doi.org/10.1051/0004-6361/201834408.

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Certain planetary nebulae (PNe) contain shells, filaments, or globules of cold gas and dust whose heating and chemistry are likely driven by UV and X-ray emission from their central stars and from wind-collision-generated shocks. We present the results of a survey of molecular line emission in the 88–236 GHz range from nine nearby (<1.5 kpc) planetary nebulae spanning a range of UV and X-ray luminosities, using the 30 m telescope of the Institut de Radioastronomie Millimétrique. Rotational transitions of thirteen molecules, including CO isotopologues and chemically important trace species, were observed and the results compared with and augmented by previous studies of molecular gas in PNe. Lines of the molecules HCO+, HNC, HCN, and CN, which were detected in most objects, represent new detections for four planetary nebulae in our study. Specifically, we present the first detections of 13CO (1–0, 2–1), HCO+, CN, HCN, and HNC in NGC 6445; HCO+ in BD+30°3639; 13CO (2–1), CN, HCN, and HNC in NGC 6853; and 13CO (2–1) and CN in NGC 6772. Flux ratios were analyzed to identify correlations between the central star and/or nebular UV and X-ray luminosities and the molecular chemistries of the nebulae. This analysis reveals a surprisingly robust dependence of the HNC/HCN line ratio on PN central star UV luminosity. There exists no such clear correlation between PN X-rays and various diagnostics of PN molecular chemistry. The correlation between HNC/HCN ratio and central star UV luminosity demonstrates the potential of molecular emission line studies of PNe for improving our understanding of the role that high-energy radiation plays in the heating and chemistry of photodissociation regions.

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41

Perna, M., M. Curti, G. Cresci, F. Mannucci, S. Rabien, C. Grillo, S. Belli, et al. "LBT/ARGOS adaptive optics observations of z ∼ 2 lensed galaxies." Astronomy & Astrophysics 618 (October 2018): A36. http://dx.doi.org/10.1051/0004-6361/201732387.

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Aims. Gravitationally lensed systems allow a detailed view of galaxies at high redshift. High spatial- and spectral-resolution measurements of arc-like structures can offer unique constraints on the physical and dynamical properties of high-z systems. Methods. We present near-infrared spectra centred on the gravitational arcs of six known z ∼ 2 lensed star-forming galaxies of stellar masses of 109−11 M⊙ and star formation rate (SFR) in the range between 10 and 400 M⊙ yr−1. Ground layer adaptive optics (AO)-assisted observations are obtained at the Large Binocular Telescope (LBT) with the LUCI spectrographs during the commissioning of the ARGOS facility. We used MOS masks with curved slits to follow the extended arched structures and study the diagnostic emission lines. LBT observations are used to demonstrate the spectroscopic capabilities of ARGOS. Results. Combining spatially resolved kinematic properties across the arc-like morphologies, emission line diagnostics and archival information, we distinguish between merging and rotationally supported systems, and reveal the possible presence of ejected gas. For galaxies that have evidence for outflows, we derive outflow energetics and mass-loading factors compatible with those observed for stellar winds in local and high-z galaxies. We also use flux ratio diagnostics to derive gas-phase metallicities. The low signal-to-noise ratio in the faint Hβ and nitrogen lines allows us to derive an upper limit of ≈0.15 dex for the spatial variations in metallicity along the slit for the lensed galaxy J1038. Conclusions. Analysed near-infrared spectra presented here represent the first scientific demonstration of performing AO-assisted multi-object spectroscopy with narrow curved-shape slits. The increased angular and spectral resolution, combined with the binocular operation mode with the 8.4 m wide eyes of LBT, will allow the characterisation of kinematic and chemical properties of a large sample of galaxies at high-z in the near future.

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42

Pfeifle, Ryan W., Claudio Ricci, Peter G. Boorman, Marko Stalevski, Daniel Asmus, Benny Trakhtenbrot, Michael J. Koss, et al. "BASS. XXIII. A New Mid-infrared Diagnostic for Absorption in Active Galactic Nuclei." Astrophysical Journal Supplement Series 261, no. 1 (July 1, 2022): 3. http://dx.doi.org/10.3847/1538-4365/ac5b65.

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Abstract In this study, we use the Swift/BAT AGN sample, which has received extensive multiwavelength follow-up analysis as a result of the BAT AGN Spectroscopic Survey, to develop a diagnostic for nuclear obscuration by examining the relationship between the line-of-sight column densities (N H), the 2–10 keV to 12 μm luminosity ratio, and WISE mid-infrared colors. We demonstrate that heavily obscured AGNs tend to exhibit both preferentially “redder” mid-infrared colors and lower values of L X,Obs./L 12 μm than less obscured AGNs, and we derive expressions relating N H to the L X,Obs./L 12 μm and L 22 μm/L 4.6 μm luminosity ratios, as well as develop diagnostic criteria using these ratios. Our diagnostic regions yield samples that are ≳80% complete and ≳60% pure for AGNs with log(N H/cm−2) ≥ 24, as well as ≳85% pure for AGNs with log ( N H / cm − 2 ) ≳ 23.5 . We find that these diagnostics cannot be used to differentiate between optically star-forming galaxies and active galaxies. Further, mid-IR contributions from host galaxies that dominate the observed 12 μm emission can lead to larger apparent X-ray deficits and redder mid-IR colors than the AGNs would intrinsically exhibit, though this effect helps to better separate less and more obscured AGNs. Finally, we test our diagnostics on two catalogs of AGNs and infrared galaxies, including the XMM-Newton XXL-N field, and we identify several known Compton-thick AGNs, as well as a handful of candidate heavily obscured AGNs based upon our proposed obscuration diagnostics.

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Bae, Hyun-Jin, Jong-Hak Woo, and Semyeong Oh. "Detecting Gas Outflows in Type-2 AGNs Selected from the Sloan Digital Sky Survey." Proceedings of the International Astronomical Union 8, S292 (August 2012): 372. http://dx.doi.org/10.1017/s1743921313001737.

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AbstractEnergetic outflow from active galactic nuclei (AGNs) may play a critical role in galaxy evolution (e.g., Silk & Rees 1998). We present a velocity diagnostic for detecting gas outflow in the narrow-line region of Type-2 AGNs using line-of-sight velocity offsets of the [O iii] λ5007 and Hα emission lines with respect to the systemic velocity of stars in host galaxies (See Figure 1). We apply the diagnostics to nearby galaxies at 0.02 < z < 0.05, 3775 AGN-host and 907 star-forming galaxies as a comparison sample, which are selected from the Sloan Digital Sky Survey DR7. After obtaining a best-fit stellar population model for the continuum and a systemic velocity based on stellar lines, we subtract the stellar component to measure velocity offsets of each emission line. We find a sample of 169 AGN-host galaxies with outflow signatures, displaying a larger velocity shift of [O iii] than that of Hα, as expected in a decelerating outflow model (Komossa et al. 2008). We find that the offset velocity of [O iii] increases with Eddington ratio, suggesting that gas outflow depends on the energetics of AGN.

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44

Poetrodjojo, Henry, Joshua J. D’Agostino, Brent Groves, Lisa Kewley, I.-Ting Ho, Jeff Rich, Barry F. Madore, and Mark Seibert. "The effects of diffuse ionized gas and spatial resolution on metallicity gradients: TYPHOON two-dimensional spectrophotometry of M83." Monthly Notices of the Royal Astronomical Society 487, no. 1 (May 4, 2019): 79–96. http://dx.doi.org/10.1093/mnras/stz1241.

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Abstract We present a systematic study of the diffuse ionized gas (DIG) in M83 and its effects on the measurement of metallicity gradients at varying resolution scales. Using spectrophotometric data cubes of M83 obtained at the 2.5m duPont telescope at Las Campanas Observatory as part of the TYPHOON programme, we separate the H ii regions from the DIG using the [S ii]/H α ratio, HIIphot (H ii-finding algorithm), and the H α surface brightness. We find that the contribution to the overall H α luminosity is approximately equal for the H ii and DIG regions. The data is then rebinned to simulate low-resolution observations at varying resolution scales from 41 pc up to 1005 pc. Metallicity gradients are measured using five different metallicity diagnostics at each resolution. We find that all metallicity diagnostics used are affected by the inclusion of DIG to varying degrees. We discuss the reasons why the metallicity gradients are significantly affected by DIG using the H ii dominance and emission line ratio radial profiles. We find that applying the [S ii]/H α cut will provide a closer estimate of the true metallicity gradient up to a resolution of 1005 pc for all metallicity diagnostics used in this study.

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45

McCann, Michael, S. Bromley, S. D. Loch, and C. P. Ballance. "Atomic data calculations for Au i–Au iii and exploration in the application of collisional-radiative theory to laboratory and neutron star merger plasmas." Monthly Notices of the Royal Astronomical Society 509, no. 4 (November 17, 2021): 4723–35. http://dx.doi.org/10.1093/mnras/stab3285.

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ABSTRACT Neutron binary star mergers have long been proposed as sufficiently neutron rich environments that could support the synthesis of rapid neutron capture elements (r-process elements) such as gold. However, the literature reveals that beyond neutral and singly ionized systems, there is an incompleteness of atomic data for the remaining ion stages of importance for mergers. In this work, we report on relativistic atomic structure calculations for Au i–Au iii using the grasp0 codes. Comparisons to calculations using the Flexible Atomic Code suggest uncertainties on average of 9.2 per cent, 5.7 per cent, and 3.8 per cent for Au i–Au iii level energies. Agreement around ∼50 per cent is achieved between our computed A-values and those in the literature, where available. Using the grasp0 structure of Au i, we calculated electron-impact excitation rate coefficients and use a collisional-radiative model to explore the excitation dynamics and line ratio diagnostics possible in neutron star merger environments. We find that proper accounting of metastable populations is critical for extracting useful information from ultraviolet–visible line ratio diagnostics of Au i. As a test of our data, we applied our electron-impact data to study a gold hollow cathode spectrum in the literature and diagnosed the plasma conditions as Te = 3.1 ± 1.2 eV and $n_\textrm {e} = 2.7^{+1.3}_{-0.9}\times 10^{13}$ cm−3.

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46

Lee, B., Y. G. Guezennec, and G. Rizzoni. "Estimation of cycle-resolved in-cylinder pressure and air-fuel ratio using spark plug ionization current sensing." International Journal of Engine Research 2, no. 4 (August 1, 2001): 263–76. http://dx.doi.org/10.1243/1468087011545479.

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In recent years, several new sensor technologies have been developed and implemented within automotive industries due to the increasing requirements for improved engine performance and emission reduction. It requires detailed and specified knowledge of the combustion process inside the engine cylinder along with a sophisticated technique in engine diagnostics and control. During the last few years, the ionization current signal detection has been the emerging technology in the new sensor developments, in which the spark plug is used as a combustion probe, to improve the performance and emissions of an automobile engine. In this paper, a novel methodology will be presented which allows the cycle-resolved as well as the mean-value estimation of the air-fuel ratio and in-cylinder pressure based on the ionization current signal measurements. The implementation details of this methodology as well as extensive results will be presented for a wide range of air-fuel ratios. The main advantage of this new approach to process the ionization signal is its strong potential for real-time estimation of the air-fuel ratio and combustion diagnostics of individual cylinders and engine cycles. All the complex physics during the actual events (combustion process, ion generation, engine dynamics, etc.) are automatically self-extracted by this technique from acquired data in an initial off-line mapping phase. Once this has been performed, the air-fuel ratio and in-cylinder pressure can easily be estimated for each individual cylinder and combustion event in real-time with few computational requirements. Hence, this methodology has a high potential for the real-time combustion diagnostics and engine control based on the air-fuel ratio and in-cylinder pressure, while eliminating the requirements for installing expensive air-fuel ratio and in-cylinder pressure sensors. The results indicate that estimation of the cycle-resolved air-fuel ratio and in-cylinder pressure is reasonably accurate and robust, despite the inherently noisy character of the ionization signals, with estimation errors typically in the order of 2 per cent or less, except for very fuel-rich conditions.

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47

Georghiou, Sophia B., Marva Seifert, Donald G. Catanzaro, Richard S. Garfein, and Timothy C. Rodwell. "Increased Tuberculosis Patient Mortality Associated with Mycobacterium tuberculosis Mutations Conferring Resistance to Second-Line Antituberculous Drugs." Journal of Clinical Microbiology 55, no. 6 (April 12, 2017): 1928–37. http://dx.doi.org/10.1128/jcm.00152-17.

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ABSTRACTRapid molecular diagnostics have great potential to limit the spread of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) (M/XDR-TB). These technologies detect mutations in theMycobacterium tuberculosisgenome that confer phenotypic drug resistance. However, there have been few data published regarding the relationships between the detectedM. tuberculosisresistance mutations and M/XDR-TB treatment outcomes, limiting our current ability to exploit the full potential of molecular diagnostics. We analyzed clinical, microbiological, and sequencing data for 451 patients and their clinical isolates collected in a multinational, observational cohort study to determine if there was an association betweenM. tuberculosisresistance mutations and patient mortality. The presence of anrrs1401G mutation was associated with significantly higher odds of patient mortality (adjusted odds ratio [OR] = 5.72; 95% confidence interval [CI], 1.65 to 19.84]) after adjusting for relevant patient clinical characteristics and all other resistance mutations. Further analysis of mutations, categorized by the associated resistance level, indicated that the detection of mutations associated with high-level fluoroquinolone (OR, 3.99 [95% CI, 1.10 to 14.40]) and kanamycin (OR, 5.47 [95% CI, 1.64 to 18.24]) resistance was also significantly associated with higher odds of patient mortality, even after accounting for clinical site, patient age, reported smoking history, body mass index (BMI), diabetes, HIV, and all other resistance mutations. SpecificgyrAandrrsresistance mutations, associated with high-level resistance, were associated with patient mortality as identified in clinicalM. tuberculosisisolates from a diverse M/XDR-TB patient population at three high-burden clinical sites. These results have important implications for the interpretation of molecular diagnostics, including identifying patients at increased risk for mortality during treatment. (This study has been registered at ClinicalTrials.gov under registration no. NCT02170441.)

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Степанов, Е. В., та С. Г. Касоев. "Многокомпонентный анализ биомаркеров в выдыхаемом воздухе методами диодной лазерной спектроскопии-=SUP=-*-=/SUP=-". Журнал технической физики 126, № 6 (2019): 810. http://dx.doi.org/10.21883/os.2019.06.47777.57-19.

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Methods of multicomponent spectral analysis of exhaled air based on application of tunable diode lases were proposed for biomedical diagnostics. Simmultaneous laser based spectral analysis of the gas pairs like CO and CO2, and CO and N2O in the 4.7 micron spectral region could be used for investigation of gas exchange in studies on breathing phisiology and cardiovascular diagnostics conducted with application of different loading tests, as well as for studies in anesteziology and for on-line monitoring of ventilation-perfusion ratio. Simmultaneous analysis of NO and CO2 in 5.4 micron region could be useful fot the control of breating maneuver in studies of inflammation processes in the distal part of the lungs. Simmultaneous detection of NH3, СO2 and C2H4 near 10.5 m could be promising in studies of basal metabolizm and metabolis cycles. Simmultaneous analisis of 13СO2 and 12С O2 near 2.05 m could be used for the detection of 13СO2/12СO2 izotope ratio for izotope breath tests. The results of promising spectral region analysis and of mutual location of absorption analytical lines in these regions are presented. A possibility of simmultaneous detection of several studied molecules in the provided spectral regions was experimetally demonstrated as well as experimental laser spectra of molecular absorption were obtained. A possibility of the proposed approach in applications to analysis of trace gases in exhaled air was demonstrated.

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49

Comerford, Julia M., James Negus, R. Scott Barrows, Dominika Wylezalek, Jenny E. Greene, Francisco Müller-Sánchez, and Rebecca Nevin. "Toward a More Complete Optical Census of Active Galactic Nuclei via Spatially Resolved Spectroscopy." Astrophysical Journal 927, no. 1 (March 1, 2022): 23. http://dx.doi.org/10.3847/1538-4357/ac496a.

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Abstract While emission line flux ratio diagnostics are the most common technique for identifying active galactic nuclei (AGNs) in optical spectra, applying this approach to single-fiber spectra of galaxies can omit entire subpopulations of AGNs. Here, we use spatially resolved spectroscopy from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey to construct a sample of 10 galaxies where Baldwin–Philips–Terlevich line flux ratio diagnostics classify each galaxy’s central 3″ spectrum as LINER or star-forming, while >10% of the spaxels in the galaxy’s MaNGA footprint are classified as Seyfert. We obtain Chandra observations of these 10 galaxies with off-nuclear Seyfert regions to determine whether AGNs are actually present in them. Our main result is that 7–10 (depending on strictness of criteria) of the galaxies host one or more X-ray AGNs, even though none of them were classified as AGNs based on their single-fiber optical spectra. We find that these AGNs were not identified in the single-fiber spectra because they are AGNs in the nuclei of companion galaxies, low-luminosity AGNs, dust-obscured AGNs, and/or flickering AGNs. In summary, we find that off-nuclear AGN signatures may increase the number of known AGNs by a factor of two over what conventional single nuclear fiber spectra identify. Our results show that spatially resolved spectroscopy can be leveraged to reveal a more complete census of AGNs that are traditionally missed by single-fiber spectra.

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Marcer, G., M. Nocente, L. Giacomelli, G. Gorini, E. Perelli Cippo, O. Putignano, M. Rebai, et al. "Study of a single line of sight gamma ray diagnostics for measurements of the absolute gamma ray emission from JET." Journal of Instrumentation 16, no. 12 (December 1, 2021): C12019. http://dx.doi.org/10.1088/1748-0221/16/12/c12019.

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Abstract The fusion power produced in a DT thermonuclear reactor is currently determined by measuring the absolute 14 MeV neutron yield of the D(T, α)n fusion reaction. Measurements of 17 MeV gamma rays born from the much less probable D(T, 5He)γ reaction (branching ratio of ∼10−5) have been proposed as an alternative independent method to validate the neutron counting method and also to fulfill the requests of the nuclear regulator for licensing ITER DT operations. However, the development of absolute 17 MeV gamma ray emission measurements entails a number of requirements, such as: (i) knowledge of the 17 MeV gamma ray to 14 MeV neutron emission branching ratio; (ii) the simulation of the gamma ray transport from the extended plasma source to the gamma ray detectors; (iii) a careful determination of the absolute efficiency of previously calibrated gamma ray spectrometers. In this work, we have studied the possibility to infer the global gamma ray emission rate from measurements made with a 3″ × 6″ LaBr3 spectrometer installed at the end of a collimated tangential line of sight at the JET tokamak and using the neutron emission from deuterium plasmas of the most recent experimental campaigns. Results show that 17 MeV gamma ray fluxes at the end of this tangential line of sight have a weak dependence (less than 5%) on the plasma profile and can therefore be used to infer the total emission from the plasma.

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