Velocity structure of self-similar spherically collapsed halos
Using a generalized self-similar secondary infall model, which accounts for tidal torques acting on the halo, we analyze the velocity profiles of halos in order to gain intuition for N-body simulation results. We analytically calculate the asymptotic behavior of the internal radial and tangential ki...
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| Format: | Article |
| Language: | en_US |
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American Physical Society
2011
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| Online Access: | http://hdl.handle.net/1721.1/62594 https://orcid.org/0000-0003-2480-5973 |
| _version_ | 1826204744402599936 |
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| author | Zukin, Phillip Gregory Bertschinger, Edmund |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Zukin, Phillip Gregory Bertschinger, Edmund |
| author_sort | Zukin, Phillip Gregory |
| collection | MIT |
| description | Using a generalized self-similar secondary infall model, which accounts for tidal torques acting on the halo, we analyze the velocity profiles of halos in order to gain intuition for N-body simulation results. We analytically calculate the asymptotic behavior of the internal radial and tangential kinetic energy profiles in different radial regimes. We then numerically compute the velocity anisotropy and pseudo–phase-space density profiles and compare them to recent N-body simulations. For cosmological initial conditions, we find both numerically and analytically that the anisotropy profile asymptotes at small radii to a constant set by model parameters. It rises on intermediate scales as the velocity dispersion becomes more radially dominated and then drops off at radii larger than the virial radius where the radial velocity dispersion vanishes in our model. The pseudo–phase-space density is universal on intermediate and large scales. However, its asymptotic slope on small scales depends on the halo mass and on how mass shells are torqued after turnaround. The results largely confirm N-body simulations but show some differences that are likely due to our assumption of a one-dimensional phase space manifold. |
| first_indexed | 2024-09-23T13:00:42Z |
| format | Article |
| id | mit-1721.1/62594 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T13:00:42Z |
| publishDate | 2011 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/625942022-10-01T12:28:16Z Velocity structure of self-similar spherically collapsed halos Zukin, Phillip Gregory Bertschinger, Edmund Massachusetts Institute of Technology. Department of Physics Bertschinger, Edmund Bertschinger, Edmund Zukin, Phillip Gregory Using a generalized self-similar secondary infall model, which accounts for tidal torques acting on the halo, we analyze the velocity profiles of halos in order to gain intuition for N-body simulation results. We analytically calculate the asymptotic behavior of the internal radial and tangential kinetic energy profiles in different radial regimes. We then numerically compute the velocity anisotropy and pseudo–phase-space density profiles and compare them to recent N-body simulations. For cosmological initial conditions, we find both numerically and analytically that the anisotropy profile asymptotes at small radii to a constant set by model parameters. It rises on intermediate scales as the velocity dispersion becomes more radially dominated and then drops off at radii larger than the virial radius where the radial velocity dispersion vanishes in our model. The pseudo–phase-space density is universal on intermediate and large scales. However, its asymptotic slope on small scales depends on the halo mass and on how mass shells are torqued after turnaround. The results largely confirm N-body simulations but show some differences that are likely due to our assumption of a one-dimensional phase space manifold. United States. National Aeronautics and Space Administration (Grant No. NNG06GG99G) 2011-05-06T19:13:32Z 2011-05-06T19:13:32Z 2010-11 2010-08 Article http://purl.org/eprint/type/JournalArticle 1550-7998 1550-2368 http://hdl.handle.net/1721.1/62594 Zukin, Phillip and Edmund Bertschinger. “Velocity Structure of Self-similar Spherically Collapsed Halos.” Phys. Rev. D 82, 104045 (2010)© 2010 The American Physical Society. https://orcid.org/0000-0003-2480-5973 en_US http://dx.doi.org/10.1103/PhysRevD.82.104045 Physical Review D Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Physical Society APS |
| spellingShingle | Zukin, Phillip Gregory Bertschinger, Edmund Velocity structure of self-similar spherically collapsed halos |
| title | Velocity structure of self-similar spherically collapsed halos |
| title_full | Velocity structure of self-similar spherically collapsed halos |
| title_fullStr | Velocity structure of self-similar spherically collapsed halos |
| title_full_unstemmed | Velocity structure of self-similar spherically collapsed halos |
| title_short | Velocity structure of self-similar spherically collapsed halos |
| title_sort | velocity structure of self similar spherically collapsed halos |
| url | http://hdl.handle.net/1721.1/62594 https://orcid.org/0000-0003-2480-5973 |
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