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Academic literature on the topic 'Abundances'

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Published: 4 June 2021
Last updated: 1 April 2023

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Journal articles on the topic "Abundances"

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Lamarche, C., J. D. Smith, K. Kreckel, S. T. Linden, N. S. J. Rogers, E. Skillman, D. Berg, et al. "Direct Far-infrared Metal Abundances (FIRA). I. M101." Astrophysical Journal 925, no. 2 (February 1, 2022): 194. http://dx.doi.org/10.3847/1538-4357/ac3b4f.

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Abstract Accurately determining gas-phase metal abundances within galaxies is critical as metals strongly affect the physics of the interstellar medium. To date, the vast majority of widely used gas-phase abundance indicators rely on emission from bright optical lines, whose emissivities are highly sensitive to the electron temperature. Alternatively, direct-abundance methods exist that measure the temperature of the emitting gas directly, though these methods usually require challenging observations of highly excited auroral lines. Low-lying far-infrared (FIR) fine structure lines are largely insensitive to electron temperature and thus provide an attractive alternative to optically derived abundances. Here, we introduce the far-infrared abundance (FIRA) project, which employs these FIR transitions, together with both radio free–free emission and hydrogen recombination lines, to derive direct, absolute gas-phase oxygen abundances. Our first target is M101, a nearby spiral galaxy with a relatively steep abundance gradient. Our results are consistent with the O++ electron temperatures and absolute oxygen abundances derived using optical direct-abundance methods by the CHemical Abundance Of Spirals (CHAOS) program, with a small difference (∼1.5σ) in the radial abundance gradients derived by the FIR/free–free-normalized versus CHAOS/direct-abundance techniques. This initial result demonstrates the validity of the FIRA methodology—with the promise of determining absolute metal abundances within dusty star-forming galaxies, both locally and at high redshift.
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Reggiani, Henrique, Kevin C. Schlaufman, Brian F. Healy, Joshua D. Lothringer, and David K. Sing. "Evidence that the Hot Jupiter WASP-77 A b Formed Beyond Its Parent Protoplanetary Disk’s H2O Ice Line." Astronomical Journal 163, no. 4 (March 10, 2022): 159. http://dx.doi.org/10.3847/1538-3881/ac4d9f.

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Abstract Idealized protoplanetary disk and giant planet formation models have been interpreted to suggest that a giant planet’s atmospheric abundances can be used to infer its formation location in its parent protoplanetary disk. It has recently been reported that the hot Jupiter WASP-77 A b has subsolar atmospheric carbon and oxygen abundances with a solar C/O abundance ratio. Assuming solar carbon and oxygen abundances for its host star WASP-77 A, WASP-77 A b’s atmospheric carbon and oxygen abundances possibly indicate that it accreted its envelope interior to its parent protoplanetary disk’s H2O ice line from carbon-depleted gas with little subsequent planetesimal accretion or core erosion. We show that the photospheric abundances of carbon and oxygen in WASP-77 A are supersolar with a subsolar C/O abundance ratio, implying that WASP-77 A b’s atmosphere has significantly substellar carbon and oxygen abundances with a superstellar C/O ratio. Our result possibly indicates that WASP-77 A b’s envelope was accreted by the planet beyond its parent protoplanetary disk's H2O ice line. While numerous theoretical complications to these idealized models have now been identified, the possibility of nonsolar protoplanetary disk abundance ratios confound even the most sophisticated protoplanetary disk and giant planet formation models. We therefore argue that giant planet atmospheric abundance ratios can only be meaningfully interpreted relative to the possibly nonsolar mean compositions of their parent protoplanetary disks as recorded in the photospheric abundances of their dwarf host stars.
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Pottasch, S. R. "Chemical composition of interstellar material." Symposium - International Astronomical Union 106 (1985): 575–84. http://dx.doi.org/10.1017/s0074180900243192.

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Abundances in interstellar clouds, as determined from interstellar absorption lines, are discussed first, including abundances in ‘abnormal’ (high-velocity) clouds. HII-region abundances are then discussed and compared to results from the interstellar clouds. The present status of an abundance gradient as determined from HII regions is given. Abundances in planetary nebulae are then given for various categories of nebulae, and compared to HII regions. Finally a short status report on abundances near the galactic center is given.
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Pérez-Mesa, V., O. Zamora, D. A. García-Hernández, Y. Ossorio, T. Masseron, B. Plez, A. Manchado, A. I. Karakas, and M. Lugaro. "On the circumstellar effects on the Li and Ca abundances in massive Galactic O-rich AGB stars." Proceedings of the International Astronomical Union 14, S343 (August 2018): 489–90. http://dx.doi.org/10.1017/s174392131800501x.

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AbstractWe explore the circumstellar effects on the Li and Ca abundances determination in a complete sample of massive Galactic AGB stars. The Li abundance is an indicator of the hot bottom burning (HBB) activation, while the total Ca abundance could be affected by overproduction of the short-lived radionuclide 41Ca by the s-process. Li abundances were previously studied with hydrostatic models, while Ca abundances are determined here for the first time. The pseudo-dynamical abundances of Li and Ca are very similar to the hydrostatic ones, indicating that circumstellar effects are almost negligible. The new Li abundances confirm the (super-)Li-rich character of the sample Li-detected stars, supporting the HBB activation in massive Galactic AGB stars. Most sample stars display nearly solar Ca abundances that are consistent with predictions from the s-process nucleosynthesis models. A minority of the sample stars show a significant Ca depletion. Possible reasons for their (unexpected) low Ca content are given.
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Reijniers, Jonas, Mike Begon, Vladimir S. Ageyev, and Herwig Leirs. "Plague epizootic cycles in Central Asia." Biology Letters 10, no. 6 (June 2014): 20140302. http://dx.doi.org/10.1098/rsbl.2014.0302.

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Infection thresholds, widely used in disease epidemiology, may operate on host abundance and, if present, on vector abundance. For wildlife populations, host and vector abundances often vary greatly across years and consequently the threshold may be crossed regularly, both up- and downward. Moreover, vector and host abundances may be interdependent, which may affect the infection dynamics. Theory predicts that if the relevant abundance, or combination of abundances, is above the threshold, then the infection is able to spread; if not, it is bound to fade out. In practice, though, the observed level of infection may depend more on past than on current abundances. Here, we study the temporal dynamics of plague ( Yersinia pestis infection), its vector (flea) and its host (great gerbil) in the PreBalkhash region in Kazakhstan. We describe how host and vector abundances interact over time and how this interaction drives the dynamics of the system around the infection threshold, consequently affecting the proportion of plague-infected sectors. We also explore the importance of the interplay between biological and detectability delays in generating the observed dynamics.
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Sherman, CS, MR Heupel, SK Moore, A. Chin, and CA Simpfendorfer. "When sharks are away, rays will play: effects of top predator removal in coral reef ecosystems." Marine Ecology Progress Series 641 (May 7, 2020): 145–57. http://dx.doi.org/10.3354/meps13307.

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Shark abundances are decreasing on many coral reefs, but the ecosystem effects of this loss are poorly understood. Rays are a prevalent mesopredator in tropical coral reef ecosystems that are preyed upon by top predators like sharks. Studies have suggested reduced predator abundances lead to increases in mesopredator abundance (mesopredator release). We examined the relationship between top predator abundances and the abundance and behaviour of 2 small benthic ray genera using baited remote underwater video systems (BRUVS) across 6 countries. Where predators were more abundant, 2 genera of small benthic rays were sighted less often, possibly because of lower abundances. Small ray behaviour was also significantly affected by predator abundance. Individuals of focal ray species visited BRUVS significantly fewer times at sites with higher predator abundances. Where predators were less abundant, rays spent significantly more time in the video frame, and were more likely to feed from bait bags. In addition to predator abundance, small ray presence was significantly influenced by reef relief and depth. Neotrygon spp. were more abundant on deeper, lower relief habitats, while Taeniura spp. were more prevalent in reef-associated shallow, high relief habitats. Overall, this study found that predator abundance had a significant effect on small benthic ray abundance and behaviour in the presence of BRUVS. Results demonstrate that changes in both abundance and behaviour associated with predator loss may make the interpretation of phenomenon like mesopredator release more difficult to identify unless behavioural effects are considered.
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Dors, Oli L. "Chemical abundances in Seyfert galaxies – VI. Empirical abundance calibration." Monthly Notices of the Royal Astronomical Society 507, no. 1 (July 30, 2021): 466–74. http://dx.doi.org/10.1093/mnras/stab2166.

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ABSTRACT We derived a bi-dimensional calibration between the emission-line ratios $R_{23}= ([\mathrm{ O}\, {\small {\rm II}}]\,\lambda 3726 +\lambda 3729 +[\mathrm{ O}\mathrm{ }\, {\small {\rm III}}]\,\lambda 4959 + \lambda 5007)/\rm H\,\beta$, ${\it P}=[([\mathrm{ O}\, {\small {\rm III}}]\,\lambda 4959+\lambda 5007)/{\rm H}\,\beta ]/R_{23}$ and the oxygen abundance relative to hydrogen (O/H) in the gas phase of Seyfert 1 and 2 nuclei. In view of this, emission-line intensity ratios for a sample of objects taken from the Sloan Digital Sky Survey Data Release 7 measured by the MPA/JHU group and direct estimates of O/H based on Te-method, adapted for active galactic nuclei (AGNs), are considered. We find no variation of R23 observed along the radii of AGNs, which shows that this line ratio is a good oxygen abundance (O/H) indicator for the class of objects considered in this work. The derived O/H = f(R23, P) relation produces O/H values similar to estimations via Te-method in a wide range of metallicities [$\rm 8.0 \: \lesssim \: 12+\log \,(O/H) \: \lesssim \: 9.2$]. Conversely to star-forming regions in the high-metallicity regime, R23 shows a positive correlation trend with O/H in AGNs. This indicates that the hardness of ionizing radiation is not affected by the metallicities in these objects or narrow-line regions are not significantly modified by changes in the spectral energy distribution due to metallicity variations.
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Rogers, Noah S. J., Evan D. Skillman, Richard W. Pogge, Danielle A. Berg, Kevin V. Croxall, Jordan Bartlett, Karla Z. Arellano-Córdova, and John Moustakas. "CHAOS. VII. A Large-scale Direct Abundance Study in M33." Astrophysical Journal 939, no. 1 (November 1, 2022): 44. http://dx.doi.org/10.3847/1538-4357/ac947d.

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Abstract The dispersion in chemical abundances provides a very strong constraint on the processes that drive the chemical enrichment of galaxies. Due to its proximity, the spiral galaxy M33 has been the focus of numerous chemical abundance surveys to study the chemical enrichment and dispersion in abundances over large spatial scales. The CHemical Abundances Of Spirals project has observed ∼100 H ii regions in M33 with the Large Binocular Telescope (LBT), producing the largest homogeneous sample of electron temperatures (T e ) and direct abundances in this galaxy. Our LBT observations produce a robust oxygen abundance gradient of −0.037 ± 0.007 dex kpc−1 and indicate a relatively small (0.043 ± 0.015 dex) intrinsic dispersion in oxygen abundance relative to this gradient. The dispersions in N/H and N/O are similarly small, and the abundances of Ne, S, Cl, and Ar relative to O are consistent with the solar ratio as expected for α-process or α-process-dependent elements. Taken together, the ISM in M33 is chemically well-mixed and homogeneously enriched from inside out, with no evidence of significant abundance variations at a given radius in the galaxy. Our results are compared to those of the numerous studies in the literature, and we discuss possible contaminating sources that can inflate abundance dispersion measurements. Importantly, if abundances are derived from a single T e measurement and T e –T e relationships are relied on for inferring the temperature in the unmeasured ionization zone, this can lead to systematic biases that increase the measured dispersion up to 0.11 dex.
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Ito, Hiroko, Wako Aoki, Satoshi Honda, Timothy C. Beers, and Nozomu Tominaga. "A very low upper limit for a Be abundance of a carbon-enhanced metal-poor star." Proceedings of the International Astronomical Union 5, S268 (November 2009): 337–38. http://dx.doi.org/10.1017/s1743921310004369.

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AbstractWe performed a 1D LTE chemical abundance analysis of an extremely metal-poor star BD+44°493 ([Fe/H]= −3.7), and set a very low upper limit for its Be abundance: A(Be) < −2.0. It may indicate that the decreasing trend of Be abundances with lower [Fe/H] still holds at [Fe/H] < −3.5, and demonstrate that high C and O abundances do not necessarily imply high Be abundances. However, since the star is a subgiant with Teff ~ 5500K, Be may be depleted.
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Flury, Sophia R., and Edward C. Moran. "Chemical abundances in active galaxies." Monthly Notices of the Royal Astronomical Society 496, no. 2 (June 6, 2020): 2191–203. http://dx.doi.org/10.1093/mnras/staa1563.

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ABSTRACT The Sloan Digital Sky Survey (SDSS) has proved to be a powerful resource for understanding the physical properties and chemical composition of star-forming galaxies in the local Universe. The SDSS population of active galactic nuclei (AGNs) remains as of yet less explored in this capacity. To extend the rigorous study of H ii regions in the SDSS to AGNs, we adapt methods for computing direct-method chemical abundances for application to the narrow-line regions (NLR) of AGNs. By accounting for triply ionized oxygen, we are able to more completely estimate the total oxygen abundance. We find a strong correlation between electron temperature and oxygen abundance due to collisional cooling by metals. Furthermore, we find that nitrogen and oxygen abundances in AGNs are strongly correlated. From the metal–temperature relation and the coupling of nitrogen and oxygen abundances, we develop a new, empirically and physically motivated method for determining chemical abundances from the strong emission lines commonly employed in flux-ratio diagnostic diagrams (BPT diagrams). Our approach, which for AGNs reduces to a single equation based on the BPT line ratios, consistently recovers direct-method abundances over a 1.5 dex range in oxygen abundance with an rms uncertainty of 0.18 dex. We have determined metallicities for thousands of AGNs in the SDSS, and in the process have discovered an ionization-related discriminator for Seyfert and LINER galaxies.
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Dissertations / Theses on the topic "Abundances"

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Diaz, Beltran A. I. "Chemical abundances in spiral galaxies." Thesis, University of Sussex, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372064.

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Cunha, Katia, Verne V. Smith, Sten Hasselquist, Diogo Souto, Matthew D. Shetrone, Prieto Carlos Allende, Dmitry Bizyaev, et al. "Adding the s-Process Element Cerium to the APOGEE Survey: Identification and Characterization of Ce ii Lines in the H-band Spectral Window." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/625301.

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Nine Ce II lines have been identified and characterized within the spectral window observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey (between lambda 1.51 and 1.69 mu m). At solar metallicities, cerium is an element that is produced predominantly as a result of the slow capture of neutrons (the s-process) during asymptotic giant branch stellar evolution. The Ce II lines were identified using a combination of a high-resolution (R = lambda/delta lambda = 100,000) Fourier Transform Spectrometer (FTS) spectrum of a Boo and an APOGEE spectrum (R. =. 22,400) of a metal-poor, but s-process enriched, red giant (2M16011638-1201525). Laboratory oscillator strengths are not available for these lines. Astrophysical gf-values were derived using alpha Boo as a standard star, with the absolute cerium abundance in alpha Boo set by using optical Ce II lines that have precise published laboratory gf-values. The near-infrared Ce II lines identified here are also analyzed, as consistency checks, in a small number of bright red giants using archival FTS spectra, as well as a small sample of APOGEE red giants, including two members of the open cluster NGC 6819, two field stars, and seven metal-poor N-and Al-rich stars. The conclusion is that this set of Ce II lines can be detected and analyzed in a large fraction of the APOGEE red giant sample and will be useful for probing chemical evolution of the s-process products in various populations of the Milky Way.
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Wesson, Roger. "Heavy element abundances in emission line nebulae." Thesis, University College London (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430104.

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Neves, Vasco de Matos Ferreira Mendes. "Abundances of elements in exoplanet host stars." Master's thesis, Universidade de Aveiro, 2008. http://hdl.handle.net/10773/15237.

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Mestrado em Física
In this work we present an uniform study of the chemical abundances of 12 elements (Si, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Na, Mg and Al) derived from the spectra of 451 stars of one of the HARPS GTO planet search programs, which has 66 planet bearing stars. The main goal of this study is the investigation of the possible differences between the abundances of the stars with and without planets. We have confirmed that there is an overabundance of metallicity in planet host stars, common to all species, as expected. We have also found that there is no difference in the galactic chemical evolution trends between stars with and without planets, as observed in the [X/Fe] vs. [Fe/H] plots. The stars that harbour planetary companions simply seem to be in the high metallicity tail of the distribution. We have only found one case of clear overabundance for a fixed [Fe/H] (HD147513) where the pollution scenario might be important. This particular star needs to be investigated in a future work. We also need to explore the possibility of the existence of a different population of stars with high [X/Fe] ratios in the region of [Fe/H] < 0 that was detected in the plots of [X/Fe] vs [Fe/H].
Neste trabalho apresentamos um estudo uniforme de abundâncias químicas de 12 elementos (Si, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Na, Mg e Al) a partir dos espectros de 451 estrelas de um dos programas HARPS GTO de procura de exoplanetas. Destas estrelas, 66 têm planetas confirmados. O objectivo principal deste trabalho é a investigação das possíveis diferenças entre as abundâncias químicas de estrelas com e sem planetas. Confirmámos que existe uma maior abundância química de todos os elementos nas estrelas com planetas, como era esperado. Constatámos também, através da análise dos gráficos de [X/Fe] vs. [Fe/H], que não existem diferenças nas tendências da evolução química da galáxia entre estrelas com e sem planetas. As estrelas que têm planetas parecem estar apenas no extremo de maior metalicidade da distribuição. Encontrámos apenas um caso em que se verifica uma maior abundância de alguns elementos para um [Fe/H] fixo (HD147513), onde o cenário de enriquecimento químico por poluição poderá ser importante. Este caso em particular precisa de ser investigado num trabalho futuro. É necessário também explorar a possível existência de uma população diferente de estrelas com maior metalicidade na região de [Fe/H] < 0 detectada nos gráficos de [X/Fe] vs. [Fe/H].
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Folsom, Colin Peter. "Chemical abundances of very young intermediate mass stars." Thesis, Queen's University Belfast, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.601478.

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On the main sequence, roughly 10-20% of A- and B-type stars display a wide range of chemical peculiarities in their photospheres. It is unknown when during stellar evolution these chemical peculiarities develop, and the mechanisms for the formation of some peculiarities are Dot fully understood. In order to provide strong observational constraints, this thesis investigates chemical abundances in Herbig Ae and Be (HAeBe) stars, which are pre-main sequence progenitors of A and B stars. A detailed abundance analysis was performed for 20 HAeBe stars, and 1 dusty young star, using high resolution, high signal-to-noise ratio spectra. The abundance analysis proceeded by directly fitting synthetic spectra to observations, determining effective temperature, surface gravity, microturbulence, and projected rotational velocity self-consistently with chemical abundances. The synthetic spectra were computed with the program ZEEMAN, which was developed further, optimising it for nonmagnetic spectrum synthesis, adding an automatic fitting routine, and parallelising the program. Eleven of the stars are found to display 'Boots chemical peculiarities, one star shows weak Ap/Bp peculiarities, and the remaining 9 stars are found to be chemically normal. The star with weak Ap/Bp peculiarities has a confirmed magnetic field detection in the literature, as do one],. Boo star and one chemically normal star. The other stars have been searched for magnetic fields, but have no confirmed detections. I argue that the large incidence of Boo chemical peculiarities among HAeSe stars provides strong evidence in favour of a selective accretion hypothesis for the formation of A Boo peculiarities. Among the magnetic stars, it appears that Ap/Bp peculiarities can form on the pre-main sequence but, unlike the main sequence, there' are also chemically normal magnetic HAeBe stars.
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Hamilton, Brandi B. "Modeling Exoplanet Interiors from Host Star Elemental Abundances." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou157382737367536.

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Miller, Benjamin Randolph. "Abundances and trends of atmospheric chlorodifluoromethane and bromomethane /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1998. http://wwwlib.umi.com/cr/ucsd/fullcit?p3035423.

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Wilson, Robert F., Johanna Teske, Steven R. Majewski, Katia Cunha, Verne Smith, Diogo Souto, Chad Bender, et al. "Elemental Abundances of Kepler Objects of Interest in APOGEE. I. Two Distinct Orbital Period Regimes Inferred from Host Star Iron Abundances." IOP PUBLISHING LTD, 2018. http://hdl.handle.net/10150/626528.

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The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has observed similar to 600 transiting exoplanets and exoplanet candidates from Kepler (Kepler Objects of Interest, KOIs), most with >= 18 epochs. The combined multi-epoch spectra are of high signal-to-noise ratio (typically >= 100) and yield precise stellar parameters and chemical abundances. We first confirm the ability of the APOGEE abundance pipeline, ASPCAP, to derive reliable [Fe/H] and effective temperatures for FGK dwarf stars-the primary Kepler host stellar type-by comparing the ASPCAP-derived stellar parameters with those from independent high-resolution spectroscopic characterizations for 221 dwarf stars in the literature. With a sample of 282 close-in (P < 100 days) KOIs observed in the APOGEE KOI goal program, we find a correlation between orbital period and host star [Fe/H] characterized by a critical period, P-crit = 8.3(-4.1)(+0.1) days, below which small exoplanets orbit statistically more metal-enriched host stars. This effect may trace a metallicity dependence of the protoplanetary disk inner radius at the time of planet formation or may be a result of rocky planet ingestion driven by inward planetary migration. We also consider that this may trace a metallicity dependence of the dust sublimation radius, but we find no statistically significant correlation with host T-eff and orbital period to support such a claim.
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Andrews, Brett H. "Decoding Galaxy Evolution with Gas-phase and Stellar Elemental Abundances." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1406218333.

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Dudley, Jonathan. "Cosmological parameter estimation using SZ-selected galaxy cluster abundances." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116972.

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The observational record of the growth of structure in the universe over cosmic time offers a unique and invaluable cosmological measure. The abundance and evolutionary history of structure in the universe are dependent upon the parameters which define the cosmological framework. In this work, we formulate a method for deriving cosmological constraints from the observed abundance of galaxy clusters. These objects are the most massive gravitationally collapsed structures in the universe and act as tracers of the underlying density field. We develop a technique for comparing theoretical cluster abundances with observed galaxy cluster catalogs. In this process, we explore and constrain the parameter space for departures from the canonical cosmological model. The motivation and framework for this investigation are presented in the opening chapters. An introduction to modern cosmological theory and methods for calculating theoretical galaxy cluster abundances are presented. A description of the physical observables associated with galaxy clusters follows, including a summary of detection methods. A cluster likelihood, defined through comparisons between observed cluster abundances with those predicted from theory, is developed.The focus of this work rests in the analysis of the cluster likelihood. The fiducial LCDM model is explored and parameter constraints are presented. The cluster dataset is shown to provide useful constraints on numerous parameters and the inclusion of supplementary data is investigated. The cluster-scale normalization parameter sigma_8 is well-constrained by this analysis, where we find sigma_8=0.745+-0.082 when considering only the cluster data and sigma_8=0.796+-0.026 for a combination of cluster and complementary datasets. The normalization of the scaling relation between the cluster observable and its mass and redshift is also constrained by this joint analysis such that, when compared with predictions from numerical simulations, we find A_SZ, meas./A_SZ, fid.=0.82+-0.17. Also explored are two extensions to the standard cosmological model, a non-cosmological-constant form of dark energy and non-Gaussian primordial fluctuations. In both cases the cluster likelihood is demonstrated to provide informative constraints, demonstrating consistency with a cosmological constant form of dark energy and Gaussian primordial fluctuations. Through a combination of cluster and complementary datasets we constrain the dark energy equation of state parameter to be w=-1.07+-0.12. The degree of non-Gaussianity inferred from a catalog of massive galaxy clusters is also constrained, finding f_NL=-36 (-491+456) at 68% confidence for a particular non-Gaussian model.
Les données observationnelles de la croissance des structures dans l'univers représentent une mesure cosmologique unique et inestimable. La quantité et l'historique d'évolution des structures dans l'univers dépendent des paramètres qui définissent le contexte cosmologique. Dans le présent travail, nous formulons une méthode pour déduire des contraintes cosmologiques à partir d'observations du nombre d'amas de galaxies. Ces objets demeurent les structures les plus massives à être issues de l'effondrement gravitationnel dans l'univers et agissent comme traceurs du champ de densité sous-jacent. Nous développons une technique servant à comparer le nombre d'amas de galaxies théorique aux données des catalogues d'amas de galaxies observés. Ce faisant, nous explorons et contraignions l'espace de paramètres à la recherche de déviations par rapport au modèle cosmologique standard. L'intérêt et le cadre de travail de cette recherche sont détaillés dans les premiers chapitres. Une introduction à la théorie de la cosmologie moderne et aux méthodes de calcul du nombre théorique d'amas de galaxies sera présentée. Ensuite, nous faisons la description des observables physiques associés aux amas de galaxies, incluant un résumé des méthodes de détection. Nous développons par après une fonction de vraisemblance des amas de galaxies définie par une comparaison entre les amas observés et les amas prédits par la théorie. Le fil conducteur de ce travail réside dans l'analyse de la fonction de vraisemblance des amas de galaxies. Le modèle standard de la cosmologie, dit LCDM, est exploré et les contraintes sur ses paramètres sont présentées. L'utilisation d'ensembles de données sur les amas de galaxies permet d'améliorer les contraintes sur plusieurs de ces paramètres. L'impact sur ces contraintes de l'ajout de données supplémentaires est également considéré. Cette analyse permet de contraindre significativement le paramètre de normalisation des fluctuations à l'échelle des amas de galaxies \sigma_8. Nous obtenons sigma_8=0.745+-0.082 en ne considérant que les données d'amas de galaxies et sigma_8=0.796+-0.026 en ajoutant des ensembles de données complémentaires. La normalisation du rapport d'échelle entre l'observable d'un amas de galaxies et sa masse est aussi contrainte par cette analyse conjointe. En comparant les résultats de notre analyse à ceux de simulations numériques, nous trouvons A_SZ, meas./A_SZ, fid.=0.82+-0.17$. Nous explorons de plus deux extensions au modèle cosmologique standard, une forme d'énergie sombre ne correspondant pas à une constante cosmologique ainsi que des fluctuations primordiales non-Gaussiennes. Dans les deux cas, la fonction de vraisemblance des amas de galaxies a permis de produire des contraintes informatives. Nous contraignons le paramètre de l'équation d'état de l'énergie sombre comme étant w=-1.07+-0.12$. En appliquant la fonction de vraisemblance à un catalogue d'amas de galaxies massifs, nous trouvons que le degré de non-Gaussianité correspond à f_NL=-36 (-491+456), à un niveau de confiance de 68%, pour un modèle de non-Gaussianité donné.
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Books on the topic "Abundances"

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Crane, Philippe, ed. The Light Element Abundances. Berlin, Heidelberg: Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/978-3-540-49169-9.

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S, Holt Stephen, and Sonneborn George, eds. Cosmic abundances: Proceedings of the Sixth Annual October Astrophysics Conference in College Park, Maryland, 9-11 October 1995. San Francisco, Calif: Astronomical Society of the Pacific, 1996.

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Meeting, COSPAR Plenary. Element abundance variations in the sun and heliosphere: Proceedings of the E2.1 Meeting of COSPAR Scientific Commission E which was held during the Thirtieth COSPAR Scientific Assembly, Hamburg, Germany, 11-21 July 1994. Oxford: Published for the Committee on Space Research [by] Pergamon, 1995.

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United States. National Aeronautics and Space Administration., ed. Coronal abundances and their variation. [Washington, DC: National Aeronautics and Space Administration, 1994.

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United States. National Aeronautics and Space Administration., ed. Coronal abundances and their variation. [Washington, DC: National Aeronautics and Space Administration, 1994.

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United States. National Aeronautics and Space Administration., ed. Coronal abundances and their variation. [Washington, DC: National Aeronautics and Space Administration, 1994.

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Böhm-Vitense, E. Silicon abundances in population I giants. [Washington, DC: National Aeronautics and Space Administration, 1992.

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Böhm-Vitense, E. Silicon abundances in population I giants. [Washington, DC: National Aeronautics and Space Administration, 1992.

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1960-, McWilliam Andrew, Rauch Michael, and Carnegie Symposium on Origin and Evolution of the Elements (2003 : Pasadena), eds. Origin and evolution of the elements. Cambridge: Cambridge University Press, 2004.

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Symposium, International Astronomical Union. The light elements and their evolution: Proceedings of the 198th Symposium of the International Astronomical Union held in Natal, RN, Brazil, 21-27 November 1999. San Francisco, Calif: Published on behalf of the International Astronomical Union by Astronomical Society of the Pacific, 1999.

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Book chapters on the topic "Abundances"

1

Maciel, W. J. "Planetary Nebulae: Abundances and Abundance Gradients." In The Evolution of The Milky Way, 81–92. Dordrecht: Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-010-0938-6_8.

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Charnley, Steven. "Molecular Abundances." In Encyclopedia of Astrobiology, 1069. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-11274-4_1008.

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Perlov, Delia, and Alex Vilenkin. "Element Abundances." In Cosmology for the Curious, 187–99. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-57040-2_13.

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Charnley, Steven B. "Molecular Abundances." In Encyclopedia of Astrobiology, 1594. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-44185-5_1008.

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Fludra, A., J. L. R. Saba, J. C. Hénoux, R. J. Murphy, D. V. Reams, J. R. Lemen, K. T. Strong, J. Sylwester, and K. G. Widing. "Coronal Abundances." In The Many Faces of the Sun, 89–142. New York, NY: Springer New York, 1999. http://dx.doi.org/10.1007/978-1-4612-1442-7_4.

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Charnley, Steven B. "Molecular Abundances." In Encyclopedia of Astrobiology, 1. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-27833-4_1008-5.

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Palme, Herbert. "Cosmic Elemental Abundances." In Encyclopedia of Earth Sciences Series, 1–7. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-39193-9_335-1.

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Palme, Herbert. "Cosmic Elemental Abundances." In Encyclopedia of Earth Sciences Series, 310–16. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-39312-4_335.

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Prantzos, Nikos. "Abundances of Elements." In Encyclopedia of Astrobiology, 4–5. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-11274-4_10.

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Prantzos, Nikos. "Abundances of Elements." In Encyclopedia of Astrobiology, 30–31. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-44185-5_10.

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Conference papers on the topic "Abundances"

1

Lewis, John S. "Abundances in planetary atmospheres." In Cosmic abundances of matter. AIP, 1989. http://dx.doi.org/10.1063/1.38012.

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Skillman, Evan D., and R. C. Kennicutt. "Abundances in dwarf galaxies." In Cosmic abundances of matter. AIP, 1989. http://dx.doi.org/10.1063/1.37981.

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Danziger, I. J. "Abundances in supernova remnants." In Cosmic abundances of matter. AIP, 1989. http://dx.doi.org/10.1063/1.37990.

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Blades, J. C., and N. Panagia. "Interstellar abundances towards SN1987A." In Cosmic abundances of matter. AIP, 1989. http://dx.doi.org/10.1063/1.38015.

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Lambert, David L. "The chemical composition of main sequence stars." In Cosmic abundances of matter. AIP, 1989. http://dx.doi.org/10.1063/1.38011.

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Peters, Bernard. "Cosmic radiation in physics, astrophysics and cosmology." In Cosmic abundances of matter. AIP, 1989. http://dx.doi.org/10.1063/1.37997.

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McDonald, Frank B. "Edward P. Ney, An Introduction." In Cosmic abundances of matter. AIP, 1989. http://dx.doi.org/10.1063/1.37998.

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Ney, Edward P. "The discovery of heavy cosmic ray nuclei." In Cosmic abundances of matter. AIP, 1989. http://dx.doi.org/10.1063/1.37999.

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Naugle, John E. "Phyllis St. Cyr Freier, An Introduction." In Cosmic abundances of matter. AIP, 1989. http://dx.doi.org/10.1063/1.38000.

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Freier, Phyllis S. "1948 revisited." In Cosmic abundances of matter. AIP, 1989. http://dx.doi.org/10.1063/1.38001.

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Reports on the topic "Abundances"

1

Kawano, L., D. Schramm, and G. Steigman. Primordial lithium: New reaction rates, new abundances, new constraints. Office of Scientific and Technical Information (OSTI), December 1986. http://dx.doi.org/10.2172/6773232.

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Parker, W. E., and J. M. Hall. Isotopic Abundances and Ratios in Arsenic Irradiated by High-Energy Neutrons. Office of Scientific and Technical Information (OSTI), June 2010. http://dx.doi.org/10.2172/1116904.

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Elkins, Dawn, and Diane Moody Spurlock. Phosphorylated Perilipin Abundances Associated with Energy Mobilization in Lactating Dairy Cows. Ames (Iowa): Iowa State University, January 2009. http://dx.doi.org/10.31274/ans_air-180814-2.

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Wimpenny, J., and G. Brennecka. Characterization of actinide abundances and isotopic compositions by HR-ICP-MS. Office of Scientific and Technical Information (OSTI), January 2022. http://dx.doi.org/10.2172/1844487.

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Tamura, T. The Elemental Abundances in the Intracluster Medium as Observed with XMM-Newton. Office of Scientific and Technical Information (OSTI), July 2004. http://dx.doi.org/10.2172/827301.

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Hayes, John. An Introduction to Isotopic Calculations. Woods Hole Oceanographic Insitution, September 2004. http://dx.doi.org/10.1575/1912/27058.

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Roberts, S., and R. Viani. Determination of mineral abundances in samples from the exploratory studies facility using x-ray diffraction. Office of Scientific and Technical Information (OSTI), January 1998. http://dx.doi.org/10.2172/328525.

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Gunnink, R. MGA (Multi-Group Analysis): A gamma-ray spectrum analysis code for determining plutonium isotopic abundances. Office of Scientific and Technical Information (OSTI), April 1990. http://dx.doi.org/10.2172/6738453.

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Gunnink, R., and W. D. Ruhter. Multiple Group Analysis (MGA): A gamma-ray spectrum analysis code for determining plutonium isotopic abundances. Office of Scientific and Technical Information (OSTI), September 1990. http://dx.doi.org/10.2172/6545403.

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Kerr, D. E., D. Smith, and P. Wilson. Anomalous kimberlite indicator mineral and gold grain abundances, Drybones Bay and Yellowknife area, Northwest Territories. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2000. http://dx.doi.org/10.4095/211293.

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