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Full-Text Articles in Physical Sciences and Mathematics

Kinematics Of The Narrow-Line Regions In The Seyfert Galaxies Ngc 4151 And Ngc 1068, Varendra Das Aug 2006

Kinematics Of The Narrow-Line Regions In The Seyfert Galaxies Ngc 4151 And Ngc 1068, Varendra Das

Physics and Astronomy Dissertations

We present a study of high-resolution long-slit spectra of the Narrow-Line Regions (NLRs) of NGC 4151 (a Seyfert 1 galaxy) and NGC 1068 (a Seyfert 2 galaxy) obtained with the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST). The spectra were retrieved from the Multimission Archive at Space Telescope (MAST) and were obtained from five and seven orbits of HST time resulting in five and seven parallel slit configurations at position angles of 52 degrees and 38 degrees for NGC 4151 and NGC 1068 respectively. The spectra have a spatial resolution of 0.2 arcsecond across and 0.1 …


Estimating The Dynamics Of Kernel-Based Evolving Networks, Gabor Csardi, Katherine J. Strandburg, Laszlo Zalanyi, Jan Tobochnik, Peter Erdi Jun 2006

Estimating The Dynamics Of Kernel-Based Evolving Networks, Gabor Csardi, Katherine J. Strandburg, Laszlo Zalanyi, Jan Tobochnik, Peter Erdi

Katherine J. Strandburg

In this paper we present the application of a novel methodology to scientific citation and collaboration networks. This methodology is designed for understanding the governing dynamics of evolving networks and relies on an attachment kernel, a scalar function of node properties, which stochastically drives the addition and deletion of vertices and edges. We illustrate how the kernel function of a given network can be extracted from the history of the network and discuss other possible applications.