Local Group Velocity Versus Gravity: Nonlinear Effects

• Autorzy: Ciecieląg P. , Chodorowski M. , Kudlicki A.
• Języki publikacji: EN

Abstrakty

EN

We use numerical simulations to study the relation between the velocity of the Local Group (LG) and its gravitational acceleration. This relation serves as a test for the kinematic origin of the CMB dipole and as a method for estimating β≡Ω^0.6/b. We calculate the misalignment angle between the two vectors and compare it to the observed value for the PSCz survey. The latter value is beyond the upper limit of the 90% confidence interval for the angle; therefore, the nonlinear effects are unlikely to be responsible for the whole observed misalignment. We also study the relation between the amplitudes of the LG velocity and gravity vectors. In an Ω=1 Universe, the smoothed gravity of the LG turns out to be a biased low estimator of the LG (unsmoothed) velocity. In an Ω=0.3 Universe, the estimator is biased high. The discussed biases are, however, only a few per cent, thus the linear theory works to good accuracy. The gravity-based estimator of the LG velocity has also a scatter that limits the precision of the estimate of β in the LG velocity-gravity comparisons. The random error of β due to nonlinear effects amounts to several per cent.

Słowa kluczowe

EN

methods: numerical; cosmology: theory; dark matter; large scale; structure of Universe

• Wydawca: Copernicus Foundation for Polish Astronomy
• Czasopismo: Acta Astronomica
• Rocznik: 2001
• Tom: Vol. 51, No. 2
• Strony: 103--115
• Opis fizyczny: Bibliogr. 23 poz., tab., wykr.

Twórcy

autor

Ciecieląg P.

• Nicolaus Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warsaw, Poland

autor

Chodorowski M.

• Nicolaus Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warsaw, Poland

autor

Kudlicki A.

• Nicolaus Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warsaw, Poland

Bibliografia

• Berlind, A.A., Narayanan, V.K., and Weinberg, D.H. 2000, Astrophys. J., 537, 537.
• Bouchet, F.R., Colombi, S., Hivon, E., and Juszkiewicz, R. 1995, Astron. Astrophys., 296, 575.
• Davis, M., Efstathiou, G., Frenk, C., and White, S.D.M. 1985, Astrophys. J., 292, 371.
• Davis, M., Strauss, M.A., and Yahil, A. 1991, Astrophys. J., 372, 394.
• Eke, V.R., Cole, S., and Frenk, C.S. 1996, MNRAS, 282, 263.
• Goroff, M.H., Grinstein, B., Rey, S.-J., and Wise, M.B. 1986, Astrophys. J., 311, 6.
• Górski, K., Davis, M., Strauss, M.A., White, S.D.M., and Yahil, A. 1989, Astrophys. J., 344, 1.
• Juszkiewicz, R., Vittorio, N., and Wyse, R.F.G. 1990, Astrophys. J., 349, 408.
• Kudlicki A., Plewa T., and Różyczka M. 1996, Acta Astron., 46, 297.
• Kudlicki A., Chodorowski, M.J., Plewa T., and Różyczka M. 2000, MNRAS, 316, 464.
• Kudlicki, A., Chodorowski, M.J., Strauss, M.A., and Cieciela˛g, P. 2001, MNRAS, in press.
• Lahav, O., Rees, M.J., Lilje, P.B., and Primack, J.R. 1991, MNRAS, 251, 128.
• Lahav, O., Kaiser, N., and Hoffman, Y. 1990, Astrophys. J., 352, 448.
• Lineweaver, C.H., Tenorio, L., Smoot, G.F.,Keegstra, P., Banday, A.J., and Lubin, P. 1996, Astrophys. J. Letters, 470, L38.
• Nusser, A., and Colberg, J.M. 1998, MNRAS, 294, 457.
• Paczyński, B., and Piran, T. 1990, Astrophys. J., 364, 341.
• Peebles, P.J.E. 1980, "The Large-Scale Structure of the Universe", Princeton University Press.
• Peebles, P.J.E. 1987, Astrophys. J., 317, 576.
• Rowan-Robinson, M., et al. 2000, MNRAS, 314, 375.
• Strauss, M.A., Yahil, A., Davis, M., Huchra, J.P., and Fisher, K. 1992, Astrophys. J., 397, 395. (S92)
• Schmoldt, I., et al. 1999, MNRAS, 304, 893. (S99)
• Scoccimarro, R., Colombi, S., Fry, J. N., Frieman, J.A., Hivon, E., and Melott, A. 1998, Astrophys. J., 496, 586.
• Sutherland, W., et al. 1999, MNRAS, 308, 289.