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Att tillskriva mening : En utvärdering av livsåskådningar i Karl Ove Knausgårds MorgonstjärnanGille, Mikael January 2021 (has links)
With the current thesis, the aim is to examine how worldviews appears in fiction literature. This contributes to a better understanding of how beliefs can be evaluated and what fiction offers. The theoretical framework consists of Arjan Marcus theory about the ascription of meaning to life (and how it can be connected to philosophy of life). Marcus theory also provides an opportunity to evaluate expressions of this. This is used for an analysis of protagonists in the novel The Morning Star, by Norwegian author Karl Ove Knausgård. In order to meet the purpose, the following questions have been set up: What expressions of life view appears from protagonists in the novel The Morning Star? And: How can these expressions be understood with Arjan Marcus theory of meaning? The results that emerge show, for example, that the meaning structure of the protagonists often contains incompatible elements, which give a verdict in action and interaction. This includes moral dilemmas of various kinds. In some cases, questioning of one's own faith and religious life causes internal conflicts. It is also striking how the protagonists own view of life often seems unconscious or implied. The present study contributes to the understanding of how philosophy of life is expressed, constituted, and how individuals ascribe meaning. The analyses show the potentials of the theory and what it can bring to further research in the subject area.
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The Structure of Classical Be Star Decretion DisksGullingsrud, Allison Danielle January 2020 (has links)
No description available.
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Exploring stellar magnetic activities with Bayesian inference / ベイズ推論による恒星磁気活動の探究Ikuta, Kai 23 March 2021 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第23006号 / 理博第4683号 / 新制||理||1672(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)准教授 野上 大作, 教授 一本 潔, 教授 太田 耕司 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
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Observational Studies of Extreme Stellar Magnetic Activities: Spots, Flares, and Mass Ejections / 高い磁気活動を示す恒星の観測的研究: 巨大黒点・スーパーフレア・質量噴出Namekata, Kousuke 23 March 2021 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第23012号 / 理博第4689号 / 新制||理||1672(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)准教授 野上 大作, 教授 太田 耕司, 教授 一本 潔 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
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Star Clusters in the Interacting Galaxy System Arp 284Peterson, Bradley W., Struck, Curtis, Smith, Beverly J., Hancock, Mark 01 December 2009 (has links)
We present results from a study of protoglobular cluster candidates in the interacting galaxy system Arp 284 (NGC 7714/5) using data from the Hubble Space Telescope (HST). Previous studies of the Antennae and M51 have suggested that the majority of young massive star clusters dissolve within 20 Myr due to mass loss. We use the evolutionary synthesis code starburst99 to estimate ages and extinctions for approximately 175 clusters visible with HST. We also use lower resolution Galaxy Evolution Explorer and ground-based Hα data to estimate the ages of the giant H ii regions in which these clusters are found, and compare the Spitzer colours of these H ii regions to those of star-forming regions in other interacting systems. The ages are also used to aid in the interpretation of Chandra X-ray data. Clusters in the tidal tails of NGC 7714 are generally found to have ages less than 20 Myr, though observational limits make the significance of this result uncertain. Older clusters, though not numerous, have nearly the same spatial distribution within the imaged portion of NGC 7714 as young clusters. The cluster population in the bridge connecting the two galaxies appears to be older, but the data in this part of the system are too limited to draw firm conclusions. The ages of the giant H ii regions in NGC 7714 are generally older than those of their constituent clusters, possibly indicating that the young clusters we detect are surrounded by their dispersed predecessors.
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An Assessment of Broad-Band Optical Colours as Age Indicators for Star ClustersHancock, M., Smith, B. J., Giroux, M. L., Struck, C. 01 September 2008 (has links)
We present an empirical assessment of the use of broad-band optical colours as age indicators for unresolved extragalactic clusters and investigate stochastic sampling effects on integrated colours. We use the integrated properties of Galactic open clusters (OCs) as models for unresolved extragalactic clusters. The population synthesis code Starburst99 (SB99) and four optical colours were used to estimate how well we can recover the ages of 62 well-studied Galactic OCs with published ages. We provide a method for estimating the ages of unresolved clusters and for reliably determining the uncertainties in the age estimates. Our results support earlier conclusions based on comparisons to synthetic clusters, namely the (U - B) colour is critical to the estimation of the ages of star-forming regions. We compare the observed optical colours with those obtained from SB99 using the published ages and get good agreement. The scatter in the (B - V)observed - (B - V)model is larger for lower luminosity clusters, perhaps due to stochastic effects.
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Ngc 4314. IV. Photometry of Star Clusters With the Hubble Space Telescope: History of Star Formation in the Vicinity of a Nuclear RingBenedict, G. Fritz, Andrew Howell, D., Jørgensen, Inger, Kenney, Jeffrey D.P., Smith, Beverly J. 01 March 2002 (has links)
Using Hubble Space Telescope (HST) WFPC2 images, we have obtained U, B, V, I, and Ha photometry for 76 star clusters in the nuclear star-forming ring of the barred spiral galaxy NGC 4314. These clusters are likely associated with an inner inner Lindblad resonance (IILR). The blue colors and Ha emission for most of these clusters imply very young ages of 1-15 Myr. Age estimates based on several reddening-free parameters indicate that the present epoch of star formation has lasted at least 30 Myr. By estimating the masses of stars in the clusters and comparing with the Ha luminosity, we conclude that a significant fraction of ongoing star formation in the nuclear ring of NGC 4314 occurs in clusters. The cluster masses identify these as young open clusters, not young globular clusters. Farther out in the galaxy, just exterior to the ring of young stars, previous ground-based observations revealed two symmetric stellar spiral arms that may be associated with an outer inner Lindblad resonance (OILR). With our HST data, we have revealed part of this structure and its colors in more detail. The spiral arm colors are consistent with stellar ages between 40 and 200 Myr. The age difference between the inner ring of young stars (IILR) and the larger oval-like feature containing the blue arms (OILR) supports an interpretation of the morphology of the nuclear region of NGC 4314 that requires a reservoir of gas that becomes more compact over time. We speculate that as the gas distribution becomes more centrally concentrated, it interacts with these two resonances. Each resonance triggers star formation, resulting in two distinct epochs of star formation.
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Stellar Population Synthesis of Star-Forming Clumps in Galaxy Pairs and Non-Interacting Spiral GalaxiesZaragoza-Cardiel, Javier, Smith, Beverly J., Rosado, Margarita, Beckman, John E., Bitsakis, Theodoros, Camps-Fariña, Artemi, Font, Joan, Cox, Isaiah S. 01 February 2018 (has links)
We have identified 1027 star-forming complexes in a sample of 46 galaxies from the Spirals, Bridges, and Tails (SB&T) sample of interacting galaxies, and 693 star-forming complexes in a sample of 38 non-interacting spiral (NIS) galaxies in 8 μm observations from the Spitzer Infrared Array Camera. We have used archival multi-wavelength UV-to IR observations to fit the observed spectral energy distribution of our clumps with the Code Investigating GALaxy Emission using a double exponentially declined star formation history. We derive the star formation rates (SFRs), stellar masses, ages and fractions of the most recent burst, dust attenuation, and fractional emission due to an active galactic nucleus for these clumps. The resolved star formation main sequence holds on 2.5 kpc scales, although it does not hold on 1 kpc scales. We analyzed the relation between SFR, stellar mass, and age of the recent burst in the SB&T and NIS samples, and we found that the SFR per stellar mass is higher in the SB&T galaxies, and the clumps are younger in the galaxy pairs. We analyzed the SFR radial profile and found that the SFR is enhanced through the disk and in the tidal features relative to normal spirals.
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Diffuse X-Ray-Emitting Gas in Major MergersSmith, Beverly J., Campbell, Kristen, Struck, Curtis, Soria, Roberto, Swartz, Douglas, Magno, Macon, Dunn, Brianne, Giroux, Mark L. 01 February 2018 (has links)
Using archived data from the Chandra X-ray telescope, we have extracted the diffuse X-ray emission from 49 equal-mass interacting/merging galaxy pairs in a merger sequence, from widely separated pairs to merger remnants. After the removal of contributions from unresolved point sources, we compared the diffuse thermal X-ray luminosity from hot gas (L X(gas)) with the global star formation rate (SFR). After correction for absorption within the target galaxy, we do not see a strong trend of L X(gas)/SFR with the SFR or merger stage for galaxies with SFR > 1 Myr-1. For these galaxies, the median L X(gas)/SFR is 5.5 ×1039 ((erg s-1)/Myr-1)), similar to that of normal spiral galaxies. These results suggest that stellar feedback in star-forming galaxies reaches an approximately steady-state condition, in which a relatively constant fraction of about 2% of the total energy output from supernovae and stellar winds is converted into X-ray flux. Three late-stage merger remnants with low SFRs and high K-band luminosities (L K ) have enhanced L X(gas)/SFR; their UV/IR/optical colors suggest that they are post-starburst galaxies, perhaps in the process of becoming ellipticals. Systems with L K < 1010 L have lower L X(gas)/SFR ratios than the other galaxies in our sample, perhaps due to lower gravitational fields or lower metallicities. We see no relation between L X(gas)/SFR and Seyfert activity in this sample, suggesting that feedback from active galactic nuclei is not a major contributor to the hot gas in our sample galaxies.
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Probing galaxy evolution through numerical simulations: mergers, gas, and star formationHani, Maan H. 27 August 2020 (has links)
Large observational surveys have compiled substantial galaxy samples with an array of different properties across cosmic time. While we have a broad understanding of how galaxies grow and build their observable properties, the details of galaxy growth and evolution pose a fundamental challenge to galaxy evolution theories. Nonetheless, galaxy evolution is ultimately regulated by the properties of the gas reservoir. In this thesis I use numerical simulations to answer key questions related to the galactic gas reservoir, and galaxy mergers: a major transformational process.
In Chapter 2 I present an analysis of 28 simulated L* galaxies to understand the physical processes that shape the massive gas reservoir surrounding galaxies (i.e. the circum-galactic medium; CGM). I show that (1) the gas and metal content of the CGM is driven by galaxy growth and the strength/presence of feedback processes, and (2) the ionisation and internal structures of the CGM are shaped by galactic outflows, and active galactic nucleus luminosity. Albeit dependent on internal galactic properties and the physical processes that shape them, the CGM remains greatly diverse, thus posing a challenge for observational surveys.
As a follow-up to my study of normal L* galaxy gas halos, in Chapter 3 I present a theoretical study of the effect of galaxy mergers on the CGM. I demonstrate that galaxy mergers can leave a strong imprint on the CGM's gas and metal content, metallicity, and size. The merger can increase (1) the CGM's metallicity by 0.2-0.3 dex within 0.5 Gyr post-merge, and (2) the metal covering fractions by factors of 2-3. In spite of the increase in the CGM's metal content, the hard ionising field during the merger can drive a decline in the covering fractions of commonly observed ions.
In Chapter 4 I shift focus to star formation, particularly the effects of galaxy mergers on star formation. While the effects of galaxy mergers have been proven observationally, theoretical predictions are limited to small binary merger suites and cosmological zoom-in studies. I present a statistical study of 27,691 post-merger galaxies from IllustrisTNG to quantify the effect of galaxy mergers on galactic star formation. I report a dependence in the merger-induced star formation rate (SFR) on mass ratio, stellar mass, gas fraction, and galaxy SFR. I also track the evolution of the effects of galaxy mergers demonstrating their decay over ~500 Myr.
In Chapter 6, I leverage galactic scaling relations to extend my work on the effects of galaxy mergers to resolved scales. However, before using the simulated resolved scaling relations, I first examine their existence and robustness. In Chapter 5, I demonstrate the emergence of the kpc-scale star forming main sequence (rSFMS) in the FIRE-2 simulations. Nonetheless, the slope of the rSFMS is dependent on the (1) star formation tracer's timescale, and (2) observed resolution, which I propose is caused by the clumpiness of star formation. I develop a toy model that quantitatively captures the effects of clumpy star formation. I then illustrate how the model can be used to characterise the mass of star-forming clumps.
Having demonstrated the existence and robustness of known scaling relations in numerical simulations, I explore the effects of galaxy mergers on resolved scales in Chapter 6. I generate synthetic observations for 1,927 post-mergers in IllustrisTNG and examine the radially-dependent merger-driven SFR enhancement, and metallicity suppression in post-mergers. Galaxy mergers preferentially boost star formation in the centres and suppress metallicities globally. The effects of the merger depends on galaxy properties such as stellar mass, SFR, mass ratio, and gas fraction. / Graduate
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