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Full-Text Articles in Physics
Hubble Space Telescope/Faint Object Spectrograph Spectroscopy Of Spatially Resolved Narrow-Line Regions In The Seyfert 2 Galaxies Ngc 2110 And Ngc 5929, Pierre Ferruit, Andrew S. Wilson, Mark Whittle, Chris Simpson, John S. Mulchaey, Gary J. Ferland
Hubble Space Telescope/Faint Object Spectrograph Spectroscopy Of Spatially Resolved Narrow-Line Regions In The Seyfert 2 Galaxies Ngc 2110 And Ngc 5929, Pierre Ferruit, Andrew S. Wilson, Mark Whittle, Chris Simpson, John S. Mulchaey, Gary J. Ferland
Physics and Astronomy Faculty Publications
We present the results of UV and optical Hubble Space Telescope/Faint Object Spectrograph spectroscopy of bright, extranuclear regions of line emission in the Seyfert galaxies NGC 2110 and NGC 5929. We have obtained spectra of the brightest region of the ``nuclear jet'' of NGC 2110 (75 pc from the nucleus) and of the southwest emission-line cloud of NGC 5929 (90 pc from the nucleus), in the G130H (1090-1605 Å), G190H (1570-2310 Å), G400H (3235-4780 Å), and G570H (4570-6820 Å) configurations. The observed line ratios are compared with the predictions of the two component (matter- and ionization-bounded, MB-IB), central source …
Megamaser Disks In Active Galactic Nuclei, John F. Kartje, Arieh Königl, Moshe Elitzur
Megamaser Disks In Active Galactic Nuclei, John F. Kartje, Arieh Königl, Moshe Elitzur
Physics and Astronomy Faculty Publications
Recent spectroscopic and VLBI-imaging observations of bright extragalactic H2O maser sources have revealed that the megamaser emission often originates in thin circumnuclear disks near the centers of active galactic nuclei (AGNs). Using general radiative and kinematic considerations and taking account of the observed flux variability, we argue that the maser emission regions are clumpy, a conclusion that is independent of the detailed mechanism (X-ray heating, shocks, etc.) driving the collisionally pumped masers. We examine scenarios in which the clumps represent discrete gas condensations (i.e., clouds) and do not merely correspond to velocity irregularities in the disk. We show …