Structure of weighted Hardy spaces in the plane

We characterize certain weighted Hardy spaces on the unit disk and completely describe their dual spaces.Comment: Submitted on 7 Nov 2013 accepted in FILOMA

On the X-ray emission mechanisms of the persistent source and very low-fluence bursts of SGR J0501+4516

We present here a detailed spectral study of the X-ray emission of the persistent source and the low-fluence bursts of SGR J0501+4516 observed during a deep XMM-Newton observation near the peak of its 2008 outburst. For the persistent emission we employ a physically motivated continuum emission model and spectroscopically determine important source properties; such as, the surface magnetic field strength and the magnetospheric scattering optical depth. We find that the magnetar surface temperature near the peak of its activity is 0.38 keV, corresponding to an emission area of 131 km^2 at a distance of 2 kpc. The surface magnetic field strength determined spectroscopically, B=2.2E14 G, is consistent with the dipole field strength inferred from the source spin and spin down rate. We fit the stacked spectra of 129 very faint bursts with a modified blackbody model and find a temperature of 1.16 keV, corresponding to an emission area of 93 km^2. We also find an evidence for cooling during the burst decay phase

Jensen multifunctions in complex analysis: continuity of plurisubharmonic envelopes

The envelopes of functions play essential role in pluripotential theory. In particular, they are used in Perron-Bremermann method to solve the Dirichlet problem: find a homogeneous solution of the Monge-Ampere operator with continuous boundary data. So it is important to classify those domains where the solution is also continuous. To characterize domains where continuous functions have continuous envelopes we use the notion of Jensen measures. These measures recently attracted the attention of quite a number of mathematicians. It should be noted that different classes of plurisubharmonic functions generate different Jensen measures. We treat these classes of Jensen measures as multifunctions. As it happens the continuity of envelopes is a consequence of such geometric properties of these multifunctions as upper and lower semicontinuity. This work will be of interest for people who work on complex analysis of several variables, especially on pluripotential theory

Operator valued Dirichlet problem in the plane

We consider an operator valued Dirichlet problem for harmonic mappings and prove the existence of a Perron-like solution. To formulate the Perron’s construction we make use of Olson’s notion of spectral order. We introduce a class of operator valued subharmonic mappings and establish some of their elementary properties

Broadband spectral investigations of SGRJ1550−5418 bursts

We present the results of our broadband (0.5−200 keV) spectral analysis of 42 SGRJ1550−5418 bursts simultaneously detected with the Swift/X-ray Telescope (XRT) and the Fermi/Gammaray Burst Monitor (GBM), during the 2009 January active episode of the source. We find that, on average, the burst spectra are better described with two blackbody functions than with the Comptonized model. Thus, our joint XRT/GBM analysis clearly shows for the first time that the SGRJ1550−5418 burst spectra might naturally be expected to exhibit a more truly thermalized character, such as a two-blackbody or even a multi-blackbody signal. We also studied the spin phase of the XRT burst emission, which indicate that the burst emitting sites on the neutron star need not to be co-located with hot spots emitting the bulk of the persistent X-ray emission and the surface magnetic field of SGRJ1550−5418 is likely non-uniform over the emission zone

Spatial, Temporal and Spectral Properties of X-ray Emission from the Magnetar SGR~0501+4516

SGR~0501+4516 was discovered with the Swift satellite on 2008 August 22, after it emitted a series of very energetic bursts. Since then, the source was extensively monitored with Swift, the Rossi X-ray Timing Explorer (RXTE) and observed with Chandra and XMM-Newton, providing a wealth of information about its outburst behavior and burst induced changes of its persistent X-ray emission. Here we report the most accurate location of SGR~0501+4516 (with an accuracy of 0.11'') derived with Chandra. Using the combined RXTE, Swift/X-ray Telescope, Chandra and XMM-Newton observations we construct a phase connected timing solution with the longest time baseline (~240 days) to date for the source. We find that the pulse profile of the source is energy dependent and exhibits remarkable variations associated with the SGR~0501+4516 bursting activity. We also find significant spectral evolution (hardening) of the source persistent emission associated with bursts. Finally, we discuss the consequences of the SGR~0501+4516 proximity to the supernova remnant, SNR G160.9+2.6 (HB9).Comment: Accepted for publication in the Ap

Is the lack of pulsations in low mass X-Ray binaries due to comptonizing coronae?

The spin periods of the neutron stars in most Low Mass X-ray Binary (LMXB) systems still remain undetected. One of the models to explain the absence of coherent pulsations has been the suppression of the beamed signal by Compton scattering of X-ray photons by electrons in a surrounding corona. We point out that simultaneously with wiping out the pulsation signal, such a corona will upscatter (pulsating or not) X-ray emission originating at and/or near the surface of the neutron star leading to appearance of a hard tail of Comptonized radiation in the source spectrum. We analyze the hard X-ray spectra of a selected set of LMXBs and demonstrate that the optical depth of the corona is not likely to be large enough to cause the pulsations to disappear

Eleştirel Düşünme Becerileri ve Problem Çözmeye Yönelik Yansıtıcı Düşünme Becerileri Arasındaki İlişkiler

This study investigates the relationship between the critical thinking skills and the reflective thinking skills toward problem solving and the effects of two variables weekly study hours and social activities on reflective and critical thinking. Positive correlations between reflective thinking and four sub-dimensions of critical thinking, analyticity, systematicity, selfconfidence, inquisitiveness, also between critical thinking skills and all three sub-dimensions of reflective thinking, questioning, reasoning, and evaluation, are found. A regression model is obtained to predict the reflective thinking skills toward problem solving with three dimensions of critical thinking skills; self-confidence, analyticity, inquisitiveness. Weekly study hours have a significant effect on both reflective and critical thinking. As time spending on studying increases until 15 hours in a week, questioning and reasoning dimensions of the reflective thinking and inquisitiveness dimension of the critical thinking are increasing. As time spending on studying increases until 20 hours in a week, only evaluation dimension of the reflective thinking are increasing. Being an active undergraduate in studying affect questioning, reasoning, evaluation skills of reflective thinking, and also inquisitiveness skill of critical thinking while social activities affect not only questioning and evaluation dimensions of reflective thinking, but also truth-seeking, open-mindedness, and systematicity dimensions of critical thinking.Bu çalışma, eleştirel düşünme becerileri ile problem çözme yönünde yansıtıcı düşünme becerileri arasındaki ilişkiyi ve iki değişkenin, haftalık çalışma ve sosyal aktivite saatlerinin yansıtıcı ve eleştirel düşünme üzerindeki etkilerini incelemektedir. Yansıtıcı düşünme ile eleştirel düşünmenin 4 alt boyutu olan Doğruyu arama, Analitik, Sistematiklik, Kendine güven arasında, ayrıca eleştirel düşünme ile yansıtıcı düşünmenin üç alt boyutu olan sorgulama, nedenleme ve değerlendirme arasında pozitif korelasyon bulunmaktadır. Yansıtıcı düşünme becerisini yordayıcı bir regresyon modeli eleştirel düşünmenin 3 alt boyutu olan Doğruyu arama, Analitik, Kendine güven boyutları ile elde edilmiştir. Haftalık çalışma saati süresi, hem eleştirel düşünme hem de yansıtıcı düşünme becerilerini etkilemektedir. Haftalık çalışma süresi 15 saate kadar arttığında, yansıtıcı düşünmenin iki alt boyutu olan sorgulama, nedenleme boyutları ve de eleştirel düşünmenin sorgulama boyutu artmaktadır. Haftalık sosyal aktivite süresi 20 saate kadar arttığında, sadece eleştirel düşünme becerisinin değerlendirme boyutu artmaktadır. Lisans öğrencilerinin ders çalışmada aktif olması yansıtıcı düşünmenin üç alt boyutu olan sorgulama, nedenleme ve değerlendirme boyutlarını ve eleştirel düşünmenin sorgulama boyutunu etkilerken, sosyal aktivitelerde aktif olmak sadece yansıtıcı düşünmenin iki alt boyutu olan sorgulama ve değerlendirme boyutlarını etkilemiyor aynı zamanda eleştirel düşünmenin 3 alt boyutu olan Doğruyu arama, Açık Fikirlilik ve Sistematiklik, boyutlarını etkilemektedir

X-ray and infrared enhancement of anomalous x-ray pulsar 1E 2259+586

The long-term ( 1.5 yr) X-ray enhancement and the accompanying infrared enhancement light curves of the anomalous X-ray pulsar 1E 2259+586 following the major bursting epoch can be accounted for by the relaxation of a fallback disk that has been pushed back by a gamma-ray flare. The required burst energy estimated from the results of our model fits is low enough for such a burst to have remained below the detection limits. We find that an irradiated disk model with a low irradiation efficiency is in good agreement with both X-ray and infrared data. Nonirradiated disk models also give a good fit to the X-ray light curve, but are not consistent with the infrared data for the first week of the enhancement