Now showing items 786-789 of 789

    • X-ray absorption analysis of MCG-6-30-15: Discerning three kinematic systems 

      Holczer, T.; Behar, E.; Arav, Nahum (IOP Publishing Ltd., 2010-01)
      By analyzing the X-ray spectrum of MCG -6-30-15 obtained with the High Energy Transmission Grating (HETGS) spectrometer on board the Chandra observatory, we identify three kinematically distinct absorption systems; two ...
    • XMM-Newton RGS observation of the warm absorber in Mrk 279 

      Ebrero, J.; Constantini, E.; Kaastra, J. S.; Detmers, R. G.; Arav, Nahum; Kriss, G. A.; Korista, K. T.; Steenbrugge, K. C. (EDP Sciences, 2010-09-10)
      Context. The Seyfert 1 galaxy Mrk 279 was observed by XMM-Newton in November 2005 on three consecutive orbits, showing significant short-scale variability (average soft band variation in flux ~20%). The source is known to ...
    • XMM-Newton unveils the complex iron K alpha region of Mrk 279 

      Costantini, E.; Kaastra, J. S.; Korista, K.; Ebrero, J.; Arav, Nahum; Kriss, G.; Steenbrugge, K. C. (EDP Sciences, 2010-03-04)
      We present the results of a similar to 160 ks-long XMM-Newton observation of the Seyfert 1 galaxy Mrk 279. The spectrum shows evidence of both broad and narrow emission features. The FeK alpha line may be equally well ...
    • α-states in de Sitter space 

      de Boer, J.; Jejjala, V.; Minic, D. (American Physical Society, 2005-02)
      Field theory in de Sitter space admits a one-parameter family of vacua determined by a superselection parameter alpha. Of these vacua, the Euclidean vacuum uniquely extrapolates to the vacuum of flat Minkowski space. States ...