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Full-Text Articles in Physical Sciences and Mathematics

The Young Radio Lobe Of 3c 84: Inferred Gas Properties In The Central 10 Pc, Yutaka Fujita, Nozomu Kawakatu, Isaac Shlosman, Hirotaka Ito Nov 2015

The Young Radio Lobe Of 3c 84: Inferred Gas Properties In The Central 10 Pc, Yutaka Fujita, Nozomu Kawakatu, Isaac Shlosman, Hirotaka Ito

Physics and Astronomy Faculty Publications

We analyse the environment of the supermassive black hole (SMBH) in the centre of a massive elliptical galaxy NGC 1275 in the Perseus cluster, hosting the radio source 3C 84. We focus on the young radio lobe observed inside the estimated Bondi accretion radius, and discusss the momentum balance between the jet associated with the lobe and the surrounding gas. The results are compared with the proper motion of the radio lobe obtained with the very long baseline interferometry. We find that under assumption of a high-density environment ( ≳ 100 cm−3), the jet power must be comparable …


On The Disk Wind Mass Loss Rates In Qsos, Nicolas A. Pereyra Nov 2015

On The Disk Wind Mass Loss Rates In Qsos, Nicolas A. Pereyra

Physics and Astronomy Faculty Publications and Presentations

We derive here a relatively simple expression for the total wind mass loss rates in QSOs within the accretion disk wind scenario. We show that the simple expression derived here for QSO disk wind mass loss rate is in a very good agreement with the more “exact” values obtained through significantly more complex and detailed numerically intensive 2.5D time-dependent simulations. Additionally we show that for typical QSO parameters, the disk itself will be emitting mostly in the UV/optical spectrum, in turn implying that the X-ray emission from QSOs likely is produced through some physical mechanism acting at radii smaller than …


The Emergence Of Negative Superhumps In Cataclysmic Variables: Smoothed Particle Hydrodynamics Simulations, David M. Thomas, Matt A. Wood Apr 2015

The Emergence Of Negative Superhumps In Cataclysmic Variables: Smoothed Particle Hydrodynamics Simulations, David M. Thomas, Matt A. Wood

Aerospace, Physics, and Space Science Faculty Publications

Negative superhumps are believed to arise in cataclysmic variable systems when the accretion disk is tilted with respect to the orbital plane. Slow retrograde precession of the line-of-nodes results in a signal—the negative superhump—with a period slightly less than the orbital period. Previous studies have shown that tilted disks exhibit negative superhumps, but a consensus on how a disk initially tilts has not been reached. Analytical work by Lai (1999, ApJ, 524, 1030) suggests that a magnetic field on the primary can lead to a tilt instability in a disk when the dipole moment is offset in angle from the …


Probing Stellar Accretion With Mid-Infrared Hydrogen Lines, Elisabetta Rigliaco, Ilaria Pascucci, Gaspard Duchene, Suzan Edwards, D. R. Ardila, C. Grady, Ignacio Mendigutía, Benjamín Montesinos, Gijs D. Mulders, Joan R. Najita, J. Carpenter, Elise Furlan, Uma Gorti, Rowin Meijerink, M. R. Meyer Feb 2015

Probing Stellar Accretion With Mid-Infrared Hydrogen Lines, Elisabetta Rigliaco, Ilaria Pascucci, Gaspard Duchene, Suzan Edwards, D. R. Ardila, C. Grady, Ignacio Mendigutía, Benjamín Montesinos, Gijs D. Mulders, Joan R. Najita, J. Carpenter, Elise Furlan, Uma Gorti, Rowin Meijerink, M. R. Meyer

Astronomy: Faculty Publications

In this paper we investigate the origin of the mid-infrared (IR) hydrogen recombination lines for a sample of 114 disks in different evolutionary stages (full, transitional, and debris disks) collected from the Spitzer archive. We focus on the two brighter H I lines observed in the Spitzer spectra, the H I (7-6) at 12.37 μm and the H I (9-7) at 11.32 μm. We detect the H I (7-6) line in 46 objects, and the H I (9-7) in 11. We compare these lines with the other most common gas line detected in Spitzer spectra, the [Ne II] at 12.81 …