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Full-Text Articles in Physics
Constraints On Radial Migration In Spiral Galaxies – Ii. Angular Momentum Distribution And Preferential Migration, Kathryne J. Daniel, Rosemary F. G. Wyse
Constraints On Radial Migration In Spiral Galaxies – Ii. Angular Momentum Distribution And Preferential Migration, Kathryne J. Daniel, Rosemary F. G. Wyse
Physics Faculty Research and Scholarship
The orbital angular momentum of individual stars in galactic discs can be permanently changed through torques from transient spiral patterns. Interactions at the corotation resonance dominate these changes and have the further property of conserving orbital circularity. We derived in an earlier paper an analytic criterion that an unperturbed stellar orbit must satisfy in order for such an interaction to occur, i.e. for it to be in a trapped orbit around corotation. We here use this criterion in an investigation of how the efficiency of induced radial migration for a population of disc stars varies with the angular momentum distribution …
The Arecibo Legacy Fast Alfa Survey: The Α.40 H I Source Catalog, Its Characteristics And Their Impact On The Derivation Of The H I Mass Function, Martha P. Haynes, Riccardo Giovanelli, Ann M. Martin, Kelley M. Hess, Amelie Saintonge, Elizabeth A. K. Adams, Gregory Hallenbeck, G. Lyle Hoffman, Shan Huang, Brian R. Kent, Rebecca A. Koopman, Emmanouil Papastergis, Sabrina Stierwalt, Thomas J. Balonek, David W. Craig, Sarah J.U. Higdon, David A. Kornreich, Jeffrey R. Miller, Aileen A. O'Donoghue, Ronald P. Olowin, Jessica L. Rosenberg, Kristine Spekkens, Parker Troischt, Eric M. Wilcots
The Arecibo Legacy Fast Alfa Survey: The Α.40 H I Source Catalog, Its Characteristics And Their Impact On The Derivation Of The H I Mass Function, Martha P. Haynes, Riccardo Giovanelli, Ann M. Martin, Kelley M. Hess, Amelie Saintonge, Elizabeth A. K. Adams, Gregory Hallenbeck, G. Lyle Hoffman, Shan Huang, Brian R. Kent, Rebecca A. Koopman, Emmanouil Papastergis, Sabrina Stierwalt, Thomas J. Balonek, David W. Craig, Sarah J.U. Higdon, David A. Kornreich, Jeffrey R. Miller, Aileen A. O'Donoghue, Ronald P. Olowin, Jessica L. Rosenberg, Kristine Spekkens, Parker Troischt, Eric M. Wilcots
Department of Physics and Astronomy Faculty Publications
We present a current catalog of 21?cm H I line sources extracted from the Arecibo Legacy Fast Arecibo L-band Feed Array (ALFALFA) survey over ~2800?deg2 of sky: the ?.40 catalog. Covering 40% of the final survey area, the ?.40 catalog contains 15,855 sources in the regions 07h30m < R.A. < 16h30m, +04? < decl.z < 0.25. A detailed analysis is presented of the completeness, width-dependent sensitivity function and bias inherent of the ?.40 catalog. The impact of survey selection, distance errors, current volume coverage, and local large-scale structure on the derivation of the H I mass function is assessed. While ?.40 does not yet provide a completely representative sampling of cosmological volume, derivations of the H I mass function using future data releases from ALFALFA will further improve both statistical and systematic uncertainties.
A 500 Kpc Hi Extension Of The Virgo Pair Ngc4532/Ddo137 Detected By The Arecibo Legacy Fast Alfa (Alfalfa) Survey, Rebecca A. Koopmann, Riccardo Giovanelli, Martha P. Haynes, Brian R. Kent, Thomas J. Balonek, Noah Brosch, James L. Higdon, John J. Salzer, Oded Spector
A 500 Kpc Hi Extension Of The Virgo Pair Ngc4532/Ddo137 Detected By The Arecibo Legacy Fast Alfa (Alfalfa) Survey, Rebecca A. Koopmann, Riccardo Giovanelli, Martha P. Haynes, Brian R. Kent, Thomas J. Balonek, Noah Brosch, James L. Higdon, John J. Salzer, Oded Spector
Department of Physics and Astronomy Faculty Publications
We report the discovery of a ~500 kpc H I extension southwest of the Virgo Cluster H I-rich pair NGC 4532/DDO 137, detected as part of the Arecibo Legacy Fast ALFA (ALFALFA) Survey. The feature is the longest and most massive H I tail structure so far found in the Virgo Cluster and, at 1.8 Mpc from M87, the most distant from the main concentration of the intracluster medium. The structure is spatially and spectrally separated into two ridges and is defined by diffuse emission and discrete clumps of mass (2.5–6.8) × 107 M☉. All emission is blueshifted with …
Evolution Of Stellar Bars In Live Axisymmetric Halos: Recurrent Buckling And Secular Growth, Inma Martinez-Valpuesta, Isaac Shlosman, Clayton Heller
Evolution Of Stellar Bars In Live Axisymmetric Halos: Recurrent Buckling And Secular Growth, Inma Martinez-Valpuesta, Isaac Shlosman, Clayton Heller
Department of Physics and Astronomy Faculty Publications
Evolution of stellar bars in disk galaxies is accompanied by dynamical instabilities and secular changes. Following the vertical buckling instability, the bars are known to weaken dramatically and develop a pronounced boxy/ peanut shape when observed edge-on. Using high-resolution N-body simulations of stellar disks embedded in live axisymmetric dark matter halos, we have investigated the long-term changes in the bar morphology, specifically the evolution of the bar size, its vertical structure, and the exchange of angular momentum. We find that following the initial buckling, the bar resumes its growth from deep inside the corotation radius and follows the ultraharmonic resonance …