Analysis of the physical properties of different types of neutron stars

Download

index.pdf

Date

2005

Author

Taşkın, Mustafa Özgür

Metadata

Show full item record

Item Usage Stats

105
views

30
downloads

This thesis is composed of three published articles. Each chapter is devoted to an article. In the first part the origin of some of the single radio pulsars with relatively low magnetic fields (B < 1e12 G) and with characteristic ages (tau) less than 1e7 years is questioned. We proposed that such pulsars might occur as a result of the disruption of high-mass X-ray binary systems after a second supernova explosion. In these binaries, mass accretion on to the surface of X-ray pulsars may lead to the decrease in the magnetic field from its value at birth (B similar to 1e12 ا 1e13 G) down to B < 1e12 G similar to the processes in low-mass X-ray binaries. In the second part we put together many observational data of SGRs and AXPs and analyzed them with the main purpose of the removal of contradiction between the real age (t) of these objects and their characteristic times of period change (tau). SGRs and AXPs are neutron stars that undergo star-quakes. Magnetic activity increases from time to time. We suggest that as a result of these processes plasma is ejected from the NS and propeller mechanism starts to work. Due to propeller effect dP/dt increases, tau decreases. Indeed, high dP/dt values are observed in SGRs and in half of the AXPs. Then, for a long time NS looses its activity, its dP/dt decreases, tau increases and rapid cooling begins. It seems that there is a possible transition between each NS stage (AXP,SGR,dim). This transient cycle may be repeated once or several times until the spin period of the neutron star becomes P > 10 - 12 s. Observational data and mainly the data of AXP 1E 1048-5937 and DRQNS RX J1308.8+2127 support this idea. In the third part dependence of the X-ray luminosity (Lx) of young single pulsars, due to ejection of relativistic particles, on electric field intensity, rate of rotational energy loss (dE/dt), magnetic field, period and some

Subject Keywords

Astrophysics.

URI

http://etd.lib.metu.edu.tr/upload/12606665/index.pdf
https://hdl.handle.net/11511/15735

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

X-ray observations of accretion powered pulsars İnam, Sıtkı Çağdaş; Baykal, Altan; Department of Physics (2004) In this thesis, X-ray observations of four accretion powered pulsars are presented. Using RXTE observations of 4U 1907+09, we found three new pulse periods of the source. We found that the source spun-down almost at a constant rate of Þ
Investigation of undergraduate students' mental models about the quantization of physical observables Didiş, Nilüfer; Eryılmaz, Ali; Erkoç, Şakir; Department of Secondary Science and Mathematics Education (2012) The purpose of this research is to investigate undergraduate students’ mental models about the quantization of physical observables. The research was guided by ethnography, case study, and content analysis integrated to each other. It focused on second-year physics and physics education students, who were taking the Modern Physics course at the Department of Physics, at Middle East Technical University. Wide range of data was collected by interview, observation, test, diary, and other documents during 2008-...
Efficient fpga implementation of image enhancement using video streams Günay, Hazan; Aşkar, Murat; Department of Electrical and Electronics Engineering (2010) This thesis is composed of three main parts; displaying an analog composite video input by via converting to digital VGA format, license plate localization on a video image and image enhancement on FPGA. Analog composite video input, either PAL or NTSC is decoded on a video decoder board; then on FPGA, video data is converted from 4:2:2 YCbCr format to RGB. To display RGB data on the screen, line doubling de-interlacing algorithm is used since it is efficient considering computational complexity and timing....
Qualitative and philosophical enquiry of aikido participants from different levels, conceptualization of aikido as different from other sports : mind and body perspectives Şentuna, Barış; Korkusuz, Feza; Department of Physical Education and Sports (2010) This thesis is made of two main parts. First main part of the thesis is based on the qualitative enquiry of twenty-three Aikido participants from different levels - beginner, intermediate, advanced- from three different dojos. Open ended questions regarding the difference of Aikido from other sports is asked to the participants. Their written responses were coded using qualitative methods. Based on coding of documents: labels, categories and themes have been generated. Second main part of this thesis is bas...
Evaluating an Immersive Virtual Learning Environment for Learning How to Design in Human-Scale Sonmez, Orkun; Sorguç, Arzu (2018-01-01) This paper presents a part of a thesis research conducted at METU. It proposes a method for evaluating the effects of an immersive virtual learning environment (IVLE) which is integrated in an architectural design/learning activity. Proposed IVLE application and design/learning activity were designed through a synthesis on constructive learning, problem-based learning, immersive technologies, and intended learning outcomes (ILOs) in learning how to design in human-scale. Immersive experience of bodily inter...

Citation Formats

M. Ö. Taşkın, “Analysis of the physical properties of different types of neutron stars,” Ph.D. - Doctoral Program, Middle East Technical University, 2005.