DOI QR코드

DOI QR Code

THE INITIAL CONDITIONS AND EVOLUTION OF ISOLATED GALAXY MODELS: EFFECTS OF THE HOT GAS HALO

  • Hwang, Jeong-Sun (School of Physics, Korea Institute for Advanced Study) ;
  • Park, Changbom (School of Physics, Korea Institute for Advanced Study) ;
  • Choi, Jun-Hwan (Department of Physics and Astronomy, University of Kentucky)
  • 투고 : 2012.09.21
  • 심사 : 2012.12.04
  • 발행 : 2013.02.28

초록

We construct several Milky Way-like galaxy models containing a gas halo (as well as gaseous and stellar disks, a dark matter halo, and a stellar bulge) following either an isothermal or an NFW density profile with varying mass and initial spin. In addition, galactic winds associated with star formation are tested in some of the simulations. We evolve these isolated galaxy models using the GADGET-3 N-body/hydrodynamic simulation code, paying particular attention to the effects of the gaseous halo on the evolution. We find that the evolution of the models is strongly affected by the adopted gas halo component, particularly in the gas dissipation and the star formation activity in the disk. The model without a gas halo shows an increasing star formation rate (SFR) at the beginning of the simulation for some hundreds of millions of years and then a continuously decreasing rate to the end of the run at 3 Gyr. Whereas the SFRs in the models with a gas halo, depending on the density profile and the total mass of the gas halo, emerge to be either relatively flat throughout the simulations or increasing until the middle of the run (over a gigayear) and then decreasing to the end. The models with the more centrally concentrated NFW gas halo show overall higher SFRs than those with the isothermal gas halo of the equal mass. The gas accretion from the halo onto the disk also occurs more in the models with the NFW gas halo, however, this is shown to take place mostly in the inner part of the disk and not to contribute significantly to the star formation unless the gas halo has very high density at the central part. The rotation of a gas halo is found to make SFR lower in the model. The SFRs in the runs including galactic winds are found to be lower than those in the same runs but without winds. We conclude that the effects of a hot gaseous halo on the evolution of galaxies are generally too significant to be simply ignored. We also expect that more hydrodynamical processes in galaxies could be understood through numerical simulations employing both gas disk and gas halo components.

키워드

참고문헌

  1. Anderson, M. E., & Bregman, J. N. 2010, Do Hot Halos Around Galaxies Contain the Missing Baryons?, ApJ, 714, 320 https://doi.org/10.1088/0004-637X/714/1/320
  2. Barnes, J. E., & Hernquist, L. 1992, Dynamics of Interacting Galaxies, ARA&A, 30, 705 https://doi.org/10.1146/annurev.aa.30.090192.003421
  3. Barnes, J. E., & Hibbard, J. E. 2009, Identikit 1: A Modeling Tool for Interacting Disk Galaxies, AJ, 137, 3071 https://doi.org/10.1088/0004-6256/137/2/3071
  4. Blumenthal, G. R., Faber, S. M., Primack, J. R., & Rees, M. J. 1984, Formation of Galaxies and Large-Scale Structure with Cold DarkMatter, Nature, 311, 517 https://doi.org/10.1038/311517a0
  5. Choi, J.-H., & Nagamine, K. 2011, Multicomponent and Variable Velocity Galactic Outflow in Cosmological Hydrodynamic Simulations, MNRAS, 410, 2579 https://doi.org/10.1111/j.1365-2966.2010.17632.x
  6. Choi, Y.-Y., Han, D.-H., & Kim, S. S. 2010, Korea Institute for Advanced Study Value-Added Galaxy Catalog, JKAS, 43, 191
  7. Dehnen, W. 1993, A Family of Potential-Density Pairs for Spherical Galaxies and Bulges, MNRAS, 265, 250 https://doi.org/10.1093/mnras/265.1.250
  8. Dekel, A., & Silk, J. 1986, The Origin of Dwarf Galaxies, Cold Dark Matter, and Biased Galaxy Formation, ApJ, 303, 39 https://doi.org/10.1086/164050
  9. Deng, X.-F., Zhang, F., Song, J., Chen, Y.-Q., & Jiang, P. 2012, The Environmental Dependence of the Fraction of 'Unconventional' Galaxies: Faint Red and Luminous Blue, JKAS, 45, 59
  10. Hernquist, L. 1990, An Analytical Model for Spherical Galaxies and Bulges, ApJ, 356, 359 https://doi.org/10.1086/168845
  11. Hernquist, L. 1993, N-body Realizations of Compound Galaxies, ApJS, 86, 389 https://doi.org/10.1086/191784
  12. Hopkins, P. F., Quataert, E., & Murray, N. 2011, Self-Regulated Star Formation in Galaxies via Momen- tum Input from Massive Stars, MNRAS, 417, 950 https://doi.org/10.1111/j.1365-2966.2011.19306.x
  13. Hwang, H. S., & Park, C. 2009, Evidence for Morphology and Luminosity Transformation of Galaxies at High Redshifts, ApJ, 700, 791 https://doi.org/10.1088/0004-637X/700/1/791
  14. Katz, N., Weinberg, D. H., & Hernquist, L. 1996, Cosmological Simulations with TreeSPH, ApJS, 105, 19 https://doi.org/10.1086/192305
  15. Kazantzidis, S., Magorrian, J., & Moore, B. 2004, Generating Equilibrium Dark Matter Halos: Inadequa- cies of the Local Maxwellian Approximation, ApJ, 601, 37 https://doi.org/10.1086/380192
  16. Kennicutt, R. C. Jr. 1998, The Global Schmidt Law in Star-Forming Galaxies, ApJ, 498, 541 https://doi.org/10.1086/305588
  17. Kim, J., Park, C., Rossi, G., Lee, S. M., & Gott, J. R. 2011, The New Horizon Run Cosmological N-Body Simulations, JKAS, 44, 217
  18. McKee, C. F., & Ostriker, J. P. 1977, A Theory of the Interstellar Medium: Three Components Regulated by Supernova Explosions in an Inhomogeneous Substrate, ApJ, 218, 148 https://doi.org/10.1086/155667
  19. McMillan, P. J., & Dehnen, W. 2007, Initial Conditions for Disc Galaxies, MNRAS, 378, 541 https://doi.org/10.1111/j.1365-2966.2007.11753.x
  20. Merritt, D. 1985, Distribution Functions for Spherical Galaxies, MNRAS, 214, 25P https://doi.org/10.1093/mnras/214.1.25P
  21. Moster, B. P., Macci`o, A. V., Somerville, R. S., Naab, T., & Cox, T. J. 2011, The Effects of a Hot Gaseous Halo in Galaxy Major Mergers, MNRAS, 415, 3750 https://doi.org/10.1111/j.1365-2966.2011.18984.x
  22. Moster, B. P., Maccio, A. V., Somerville, R. S., Naab, T., & Cox, T. J. 2012, The Effects of a Hot Gaseous Halo on Disc Thickening in Galaxy Minor Mergers, MNRAS, 423, 2045 https://doi.org/10.1111/j.1365-2966.2012.20915.x
  23. Navarro, J. F., Frenk, C. S., & White, S. D. M. 1996, The Structure of Cold Dark Matter Halos, ApJ, 462, 563 https://doi.org/10.1086/177173
  24. Osipkov, L. P. 1979, Spherical Systems of Gravitating Bodies with an Ellipsoidal Velocity Distribution, Pis'ma Astr. Zh., 5, 77
  25. Park, C., & Choi, Y.-Y. 2009, Combined Effects of Galaxy Interactions and Large-Scale Environment on Galaxy Properties, ApJ, 691, 1828 https://doi.org/10.1088/0004-637X/691/2/1828
  26. Park, C., Gott, J. R., & Choi, Y.-Y. 2008, Transformation of Morphology and Luminosity Classes of the SDSS Galaxies, ApJ, 674, 784 https://doi.org/10.1086/524192
  27. Park, C., & Hwang, H. S. 2009, Interactions of Galaxies in the Galaxy Cluster Environment, ApJ, 699, 1595 https://doi.org/10.1088/0004-637X/699/2/1595
  28. Salpeter, E. E. 1955, The Luminosity Function and Stellar Evolution, ApJ, 121, 161 https://doi.org/10.1086/145971
  29. Springel, V. 2005, The Cosmological Simulation Code GADGET-2, MNRAS, 364, 1105 https://doi.org/10.1111/j.1365-2966.2005.09655.x
  30. Springel, V., Di Matteo, T., & Hernquist, L. 2005, Modelling Feedback from Stars and Black Holes in Galaxy Mergers, MNRAS, 361, 776 https://doi.org/10.1111/j.1365-2966.2005.09238.x
  31. Springel, V., & Hernquist, L. 2002, Cosmological Smoothed Particle Hydrodynamics Simulations: The Entropy Equation, MNRAS, 333, 649 https://doi.org/10.1046/j.1365-8711.2002.05445.x
  32. Springel, V., & Hernquist, L. 2003, Cosmological Smoothed Particle Hydrodynamics Simulations: A Hybrid Multiphase Model for Star Formation, MNRAS, 339, 289 https://doi.org/10.1046/j.1365-8711.2003.06206.x
  33. Toomre, A., & Toomre, J. 1972, Galactic Bridges and Tails, ApJ, 178, 623 https://doi.org/10.1086/151823

피인용 문헌

  1. Effects of the initial conditions on cosmological N-body simulations vol.30, 2014, https://doi.org/10.1016/j.newast.2014.01.007
  2. EFFECTS OF HOT HALO GAS ON STAR FORMATION AND MASS TRANSFER DURING DISTANT GALAXY–GALAXY ENCOUNTERS vol.805, pp.2, 2015, https://doi.org/10.1088/0004-637X/805/2/131
  3. ON THE GALACTIC SPIN OF BARRED DISK GALAXIES vol.775, pp.1, 2013, https://doi.org/10.1088/0004-637X/775/1/19