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Full-Text Articles in Physical Sciences and Mathematics
A Global View Of The Inner Accretion And Ejection Flow Around Super Massive Black Holes, Margherita Giustini, Daniel Proga
A Global View Of The Inner Accretion And Ejection Flow Around Super Massive Black Holes, Margherita Giustini, Daniel Proga
Physics & Astronomy Faculty Research
Context. Understanding the physics and geometry of accretion and ejection around super massive black holes (SMBHs) is important to understand the evolution of active galactic nuclei (AGN) and therefore of the large scale structures of the Universe. Aims. We aim at providing a simple, coherent, and global view of the sub-parsec accretion and ejection flow in AGN with varying Eddington ratio, ṁ, and black hole mass, MBH. Methods. We made use of theoretical insights, results of numerical simulations, as well as UV and X-ray observations to review the inner regions of AGN by including different accretion and ejection modes, with …
Space Telescope And Optical Reverberation Mapping Project. Viii. Time Variability Of Emission And Absorption In Ngc 5548 Based On Modeling The Ultraviolet Spectrum, Gerard A. Kriss, Gisella De Rosa, Justin Ely, Bradley M. Peterson, J. Kaastra, M. Mehdipour, Gary J. Ferland, Maryamossadat Dehghanian, S. Mathur, Rick Edelson, Kirk T. Korista, N. Arav, Aaron J. Barth, Misty C. Bentz, W. Niel Brandt, D. Michael Crenshaw, E. Dalla Bonta, K. D. Kenney, C. Done, Michael Eracleous, Michael M. Fausnaugh, E. Gardner, Michael R. Goad, Catherine J. Grier, Keith Horne, Christopher S. Kochanek, I. M. Mchardy, Hagai Netzer, Anna Pancoast, L. Pei, Richard W. Pogge, Daniel Proga
Space Telescope And Optical Reverberation Mapping Project. Viii. Time Variability Of Emission And Absorption In Ngc 5548 Based On Modeling The Ultraviolet Spectrum, Gerard A. Kriss, Gisella De Rosa, Justin Ely, Bradley M. Peterson, J. Kaastra, M. Mehdipour, Gary J. Ferland, Maryamossadat Dehghanian, S. Mathur, Rick Edelson, Kirk T. Korista, N. Arav, Aaron J. Barth, Misty C. Bentz, W. Niel Brandt, D. Michael Crenshaw, E. Dalla Bonta, K. D. Kenney, C. Done, Michael Eracleous, Michael M. Fausnaugh, E. Gardner, Michael R. Goad, Catherine J. Grier, Keith Horne, Christopher S. Kochanek, I. M. Mchardy, Hagai Netzer, Anna Pancoast, L. Pei, Richard W. Pogge, Daniel Proga
Physics & Astronomy Faculty Research
We model the ultraviolet spectra of the Seyfert 1 galaxy NGC 5548 obtained with the Hubble Space Telescope during the 6 month reverberation mapping campaign in 2014. Our model of the emission from NGC 5548 corrects for overlying absorption and deblends the individual emission lines. Using the modeled spectra, we measure the response to continuum variations for the deblended and absorption-corrected individual broad emission lines, the velocity-dependent profiles of Lyα and C iv, and the narrow and broad intrinsic absorption features. We find that the time lags for the corrected emission lines are comparable to those for the original data. …
Cloud Coalescence: A Dynamical Instability Affecting Multiphase Environments, Tim Waters, Daniel Proga
Cloud Coalescence: A Dynamical Instability Affecting Multiphase Environments, Tim Waters, Daniel Proga
Physics & Astronomy Faculty Research
Mass and size distributions are the key characteristics of any astrophysical object, including the densest clumps comprising the cold phase of multiphase environments. In our recent papers, we showed how individual clouds of various sizes form and evolve in active galactic nuclei. In particular, we showed that large clouds undergo damped oscillations as a response to their formation process. Here we follow up this investigation, addressing how different size clouds interact. We find that smaller clouds become trapped in the advective flows generated by larger clouds. The explanation for this behavior leads to a rather remarkable conclusion: even in the …
Non-Isobaric Thermal Instability, Tim Waters, Daniel Proga
Non-Isobaric Thermal Instability, Tim Waters, Daniel Proga
Physics & Astronomy Faculty Research
Multiphase media have very complex structure and evolution. Accurate numerical simulations are necessary to make advances in our understanding of this rich physics. Because simulations can capture both the linear and nonlinear evolution of perturbations with a relatively wide range of sizes, it is important to thoroughly understand the stability of condensation and acoustic modes between the two extreme wavelength limits of isobaric and isochoric instability as identified by Field. Partially motivated by a recent suggestion that large non-isobaric clouds can "shatter" into tiny cloudlets, we revisit the linear theory to survey all possible regimes of thermal instability. We uncover …