Discovery of Gamma-ray Emission from M31 via FERMI-LAT

2 years worth of archival FERMI-LAT data was used to search for the gamma-ray emission from the Andromeda galaxy. The data show no noticeable elliptical image. Subsequent on-off source aperture photometry analysis using a CO image template show a 7 sigma excess in the number of on-source apertures in comparison to the off-source apertures, yielding a flux of (4.95+/-0.71)x10-8 photons cm-2 s-1 for E>100 MeV.Comment: 7 pages, 5 figure

Sınıf ögretmeni adaylarinin bazi degigkenler açisindan fen ögretimi öz-yeterlik gnanç düzeylerinin ve sonuç beklentilerinin gncelenmesi üzerine bir aragtirma

[No abstract available

DEFPOS H? observations of Hii regions

We present H? emission line measurements of northern bright Hii regions selected from the Sharpless (1959) catalog near the Galactic plane (b ? ± 6°). A total of 10 Hii regions were observed with DEFPOS (Dual Etalon Fabry-Perot Optical Spectrometer) system at the f/48 Coude focus of 150 cm RTT150 telescope located at TUBITAK National Observatory (TUG) in Antalya/Turkey. The intensities, the local standard of rest (LSR) velocities (VLSR), and the linewidths (Full Width Half Maximum: FWHM) of the H? emission line from our observations were in the range of 84 to 745 Rayleigh (R [one Rayleigh (R) is 106/4? photons cm-2 sr-1 s-1 = 2.4110-7 erg cm-2 sr -1 s-1 at H? and corresponds to an emission measure (EM=?ne2dl) of 2.3 pc cm-6 for a gas temperature of 8000 K, where ne is the averaged electron density within an emitting region in the interstellar medium; dl is distance element to the source region (Haffner et al., 2003; Reynolds et al., 2005), 3 to -43 km s-1 and 30 to 73 km s-1, respectively. The LSR velocities and the linewidths from the data were obtained and compared with early results. We found that our results are in close agreement with them. Moreover, associated stars of some of the Hii regions were updated by analyzing their location, velocities, and brightness. © 2011 Elsevier Ltd.104T252All observations were performed from the RTT150 so we thank to TUBITAK for a partial support in using RTT150 (Russian-Turkish 1.5-m telescope in Antalya) with project number 09ARTT150–436-1. We also thank to TUBITAK National Observatory (TUG) and TUG stuff. The authors also would like to thank R. J. Reynolds from the University of Wisconsin for his valuable help in the optical design of the DEFPOS as well as to start this study. We are grateful to S.K. Yerli and M.E. Ozel for reading and correcting the manuscript and for their remarks. We special thank an anonymous referee for helpful comments. This work is supported by the TUBITAK (The Scientific and Technical Research Council of Turkey) with Grant No. 104T252. NA gratefully acknowledges support through a Post-Doc Fellowship from the TUBITAK-BIDEB at Physics Department of Middle East Technical University. This work also supported with Academic Research Project unit of Cukurova University with Grand No. TBMYO2010BAP4

Daily global solar radiation mapping of Turkey using Meteosat satellite data

Many studies have indicated that the estimation of solar irradiation at ground level using meteorological satellite data has been an alternative and easy method compared to classical methods. In the present work, the incident of solar radiation over Turkey has been estimated at ground level between July 1997 and December 1998. Statistical regressions between ground data and digital satellite data, measured in the visible band (0.4-1.1 µm) by Meteosat radiometer, have been determined and these regression parameters have been used to estimate solar radiation at ground level. This is the so-called statistical method, which uses a simple model because satellites measure only a few parameters among the many that govern radiative transfers. The visible image (C3D) data used in the present work was Meteosat Wefax type. While pursuing our studies the mean daily sum of global solar radiation over Turkey has been determined to be 18.44 MJ m-2 d-1 with a correlation coefficient of 0.96. The rms error for the mean daily sum has been evaluated as 1.92 MJ m-2 d-1. The monthly mean daily sum of solar radiation has been determined with an rms error of 1.82 MJ m-2 d-1 in two years. During this period the maximum value of the daily sum has been found to occur in June 1998 as 28.47 MJ m-2 d-1, whereas the minimum has been found to occur in December 1998 as 7.35 MJ m-2 d-1. The evaluation procedure, results and possible sources of error are suggested and possible ways of improving the method are described and discussed. © 2004 Taylor & Francis Ltd

Comparison of a new algorithm with the supervised classifications

In this study, a new classification algorithm in which only the selected pixels have been attempted to be classified (selected pixels classification: SPC) has been introduced and compared with the well known supervised classification methods such as maximum likelihood, minimum distance, nearest neighbour and condensed nearest neighbour. To examine the algorithm. Landsat Thematic Mapper (TM) data have been used to classify the crop cover in the selected region. It is clearly demonstrated that the SPC method has the higher accuracy with comparable CPU times

IMPROVED Cr II log(gf) VALUES AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937

WOS: 000394510000002PubMed ID: 28579650New emission branching fraction (BF) measurements for 183 lines of the second spectrum of chromium (Cr II) and new radiative lifetime measurements from laser-induced fluorescence for 8 levels of Cr+ are reported. The goals of this study are to improve transition probability measurements in Cr II and reconcile solar and stellar Cr abundance values based on Cr I and Cr II lines. Eighteen spectra from three Fourier Transform Spectrometers supplemented with ultraviolet spectra from a high-resolution echelle spectrometer are used in the BF measurements. Radiative lifetimes from this study and earlier publications are used to convert the BFs into absolute transition probabilities. These new laboratory data are applied to determine the Cr abundance log e in the Sun and metal-poor star HD 84937. The mean result in the Sun is - 5.624 +/- 0.009 compared to - 5.644 +/- 0.006 on a scale with the hydrogen abundance log epsilon(H) = 12 and with the uncertainty representing only line-to-line scatter. A Saha (ionization balance) test on the photosphere of HD 84937 is also performed, yielding = 3.417 +/- 0.006 and 0 eV)> = 3.374 +/- 0.011 for this dwarf star. We find a correlation of Cr with the iron-peak element Ti, suggesting an associated nucleosynthetic production. Four iron-peak elements (Cr along with Ti, V, and Sc) appear to have a similar (or correlated) production history-other iron-peak elements appear not to be associated with Cr.NASANational Aeronautics & Space Administration (NASA) [NNX16AE96G, NNH10AN381]; NSFNational Science Foundation (NSF) [AST1516182, AST-1211585]; Technological and Scientific Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK); National Science FoundationNational Science Foundation (NSF) [PHY-1430152]We thank the referee for helpful comments that have led to improvements in the paper. This work is supported in part by NASA grant NNX16AE96G (J.E.L.), by NSF grant AST1516182 (J.E.L. and E.D.H.), by NASA interagency agreement NNH10AN381 (G.N.), and NSF grant AST-1211585 (C.S.). Postdoctoral research support for N.E. is from the Technological and Scientific Research Council of Turkey (TUBITAK). J.J.C. acknowledges support by the National Science Foundation under grant No. PHY-1430152 (JINA Center for the Evolution of the Elements). The authors are grateful to Dr. Craig Sansonnetti for recording FTS Spectrum # 18