Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 15 of 15 for “"Chandra x-ray observatory"”.
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Coronal properties of pre-main sequence stars in the Orion Trapezium Cluster
… Trapezium Cluster are much more peculiar in X-rays than expected, considering their structure, environment, and age. Highly resolved X-ray spectra provide many more details in order to study these peculiarities, specifically with respect to abundances and accretion signatures. We analyzed the …
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Accreting Compact Objects in Technicolor: Multiwavelength Characterization of High Mass X-ray Binaries in the Local Group
High mass X-ray binaries (HMXBS) are systems that contain a compact object (neutron star or black hole) that accretes mass from a massive stellar companion. HMXBs are highly observable due to their bright X-ray luminosities, making them an observational window into the complex process of massive …
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X-ray astronomy with CCDs : calibration of the advanced CCD imaging spectrometer and observations of rotation-powered pulsars
… the use of charge coupled devices (CCDs) for X-ray astronomy. Part I of this thesis focuses on the calibration of the Advanced CCD Imaging Spectrometer (ACIS), one of the two primary focal plane instruments on the Chandra X-ray Observatory. I begin by presenting a series of measurements made …
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X-ray spectroscopy of low-mass X-ray binaries
I present high-resolution X-ray grating spectroscopy of neutron stars in low-mass X-ray binaries (LMXBs) using instruments onboard the Chandra X-ray Observatory and the X-ray Multi-Mirror Mission (XMM-Newton). The first part of this thesis concentrates on results from the subset of LMXBs with …
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Very old and very young compact objects : X-ray studies of galactic globular clusters and recent core-collapse supernovae
… of two distinct areas of research, namely, X-ray studies of Galactic globular clusters and X-ray studies of recent core collapse supernovae. My analyses of the Chandra X-ray Observatory observations of the globular clusters NGC 6752 and NGC 6440 revealed as many low-luminosity X-ray sources as …
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Determinations of the radii, redshifts, and atmospheric compositions of neutron stars from modeling their Chandra X-ray spectra
Fitting the X-ray spectra of thermal radiation from neutron stars with realistic atmosphere models provides a way to place constraints on their radii, surface gravities and compositions, and to test general relativity in the strong field limit. Such determinations allow us to constrain the the …
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Quasar spectroscopy in UV and X-ray- probing the intergalactic medium using helium and oxygen
We employ ultraviolet (UV) and X-ray quasar spectroscopy to study the physical state of the Intergalactic Medium (IGM). First, we quantify the possibility of measuring the temperature of moderately over-dense regions of the IGM at high redshift (z [approx.] 2) using the strongest resonant …
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HETE, the High Energy Transient Explorer : unlocking the mysteries of gamma ray bursts
… in October 2000 with the goal of studying Gamma Ray Bursts (GRBs) at X-ray and gamma-ray energies. A suite of instruments aboard HETE provide broadband sensitivity to GRBs: the French Gamma Telescope (FREGATE; 6 keV to > 400 keV ) instrument provides sensitive detections at gamma-ray energies, …
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The Connection Between X-Ray Binaries and Star Clusters in the Andromeda Galaxy
The exploration of X-ray binaries (XRBs) and their relationship with star clusters is an important aspect of astrophysics, offering insights into the processes that govern stellar evolution and the dynamical interactions within star clusters. XRBs are fascinating astronomical systems where a star …
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X-ray spectroscopy of neutron star low-mass X-ray binaries
… of topics relating to neutron star lowmass X-ray binaries (LMXBs) and utilize spectral information from X-ray observations to further our understanding of these sources. First, I give an overview of important X- ray astrophysics relevant to the work I present in subsequent chapters, as well as …
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The galaxy cluster environments of wide angle tail radio sources
… bent due to their interaction with the hot, X-ray bright intracluster medium (ICM). They have been proven to be good tracers of high redshift clusters where X-ray and optical observations are more difficult. Nonetheless, it has been unclear whether a WATs presence is directly linked to cluster …
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Comprehensive Model of Jupiter's Polar Aurora
The source of auroral X-ray emission from the Jovian polar caps, whether from electron bremsstrahlung or heavy ion precipitation, has been a topic of debate for the past 40 years, beginning with the Einstein Observatory's first measurement of X-ray emission in 1979. Since then the Roentgen …
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A 3-dimensional analysis of the Cassiopeia a supernova remnant.
… Finally, we present a detailed multi-epoch X-ray analysis of Cas A using Chandra X-ray Observatory exposures from 2000, 2002, and 2004. We identify the most recently shocked X-ray ejecta with ionization timescales of #24;1010 cm−3 s, nearly an order of magnitude smaller than previously …