G. Iannicola, M. Monelli, G. Bono, P. B. Stetson, R. Buonanno, A. Calamida, M. Zoccali, F. Caputo, M. Castellani, C. Corsi, M. Dall’Ora, A. Di Cecco, S. Degl’Innocenti, I. Ferraro, M. Nonino, A. Pietrinferni, L. Pulone, P. G. Prada Moroni, M. Romaniello, N. Sanna, A. R. Walker,
We present accurate new ultraviolet and optical BVI photometry for the Galactic globular cluster NGC 2808 based on both ground-based and archival Hubble Space telescope imagery. From this we have selected a sample of ∼2000 Horizontal Branch (HB) stars; given the extensive wavelength range considered and the combination of both high angular resolution and wide-field photometric coverage, our sample should be minimally biased. We divide the HB stars into three radial bins and find that the relative ...
Tópico(s): Astronomy and Astrophysical Research
2009 - IOP Publishing | The Astrophysical Journal
Aims: Our aim is to obtain ages that are as accurate as possible for the seven nearby open clusters alpha Per, Coma Ber, IC 2602, NGC 2232, NGC 2451A, NGC 2516, and NGC 6475, each of which contains at least one magnetic Ap or Bp star. Simultaneously, we test the current calibrations of Te and luminosity for the Ap/Bp star members, and identify clearly blue stragglers in the clusters studied. Methods: We explore the possibility that isochrone fitting in the theoretical Hertzsprung-Russell diagram ( ...
Tópico(s): Astro and Planetary Science
2014 - EDP Sciences | Astronomy and Astrophysics
There is some controversy on the nature of dust clouds found in direction of the interacting galaxy triplett M81, M82, and NGC3077. Are they associated with the tidal arms seen in HI around those galaxies or are they simply Galactic foreground clouds? Data from the SPIRE instrument onboard HERSCHEL and MIPS onboard of SPITZER are used to derive physical parameters for the dust clouds. These observions are compared to CO clouds previously mapped with the IRAM and the FCRAO radio telescopes.SPIRE ...
Tópico(s): Astrophysical Phenomena and Observations
2012 - EDP Sciences | Astronomy and Astrophysics
محمد شهاب محمد عبد الحميد, ابراهيم زكريا الشربيني, سعاد حامد العبد,
... إلى وجود علاقة تأثير موجب لاستهلاك الغاز الطبيعي ( NGC)، تصدير الغاز الطبيعي (NGE)، الاستثمار الأجنبي المباشر (FDI) ...
Tópico(s): Oil, Gas, and Environmental Issues
2025 - | المجلة العلمية للدراسات والبحوث المالية والتجارية