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Full-Text Articles in Physical Sciences and Mathematics
The Galaxy Angular Correlation Functions And Power Spectrum From The Two Micron All Sky Survey, Ah Maller, Dh Mcintosh, N Katz, Md Weinberg
The Galaxy Angular Correlation Functions And Power Spectrum From The Two Micron All Sky Survey, Ah Maller, Dh Mcintosh, N Katz, Md Weinberg
Astronomy Department Faculty Publication Series
We calculate the angular correlation function of galaxies in the Two Micron All Sky Survey. We minimize the possible contamination by stars, dust, seeing, and sky brightness by studying their cross correlation with galaxy density and limiting the galaxy sample accordingly. We measure the correlation function at scales between 1' < θ < 18° using a half-million galaxies. We find that a best-fit power law to the correlation function has a slope of -0.79 ± 0.02 and an amplitude at 1° of 0.10 ± 0.01 in the range 1'-2fdg5. However, there are statistically significant oscillations around this power law. The largest oscillation occurs at about 0fdg8, corresponding to 700 h-1 kpc at the median redshift of our survey, as expected in halo occupation distribution descriptions of galaxy clustering. In addition, there is a break in the power-law shape of the correlation function at θ > 2fdg5. Our results are in good agreement with other measurements of the angular correlation function. We invert the angular correlation function using singular value decomposition to measure the three-dimensional power spectrum and find that it too is in good agreement with previous measurements. A dip seen in the power spectrum …
Theoretical Models Of The Halo Occupation Distribution: Separating Central And Satellite Galaxies, Z Zheng, Aa Berlind, Dh Weinberg, Aj Benson, Cm Baugh, S Cole, R Dave, Cs Frenk, N Katz, Cg Lacey
Theoretical Models Of The Halo Occupation Distribution: Separating Central And Satellite Galaxies, Z Zheng, Aa Berlind, Dh Weinberg, Aj Benson, Cm Baugh, S Cole, R Dave, Cs Frenk, N Katz, Cg Lacey
Astronomy Department Faculty Publication Series
The halo occupation distribution (HOD) describes the relation between galaxies and dark matter at the level of individual dark matter halos. The properties of galaxies residing at the centers of halos differ from those of satellite galaxies because of differences in their formation histories. Using a smoothed particle hydrodynamics (SPH) simulation and a semianalytic (SA) galaxy formation model, we examine the separate contributions of central and satellite galaxies to the HOD, more specifically to the probability P(N|M) that a halo of virial mass M contains N galaxies of a particular class. In agreement with earlier …
Interpreting The Relationship Between Galaxy Luminosity, Color, And Environment, Aa Berlind, Mr Blanton, Dw Hogg, Dh Weinberg, R Dave, Dj Eisenstein, N Katz
Interpreting The Relationship Between Galaxy Luminosity, Color, And Environment, Aa Berlind, Mr Blanton, Dw Hogg, Dh Weinberg, R Dave, Dj Eisenstein, N Katz
Astronomy Department Faculty Publication Series
We study the relationship between galaxy luminosity, color, and environment in a cosmological simulation of galaxy formation. Using a simple prescription to assign colors and luminosities to simulated galaxies, we compare the predicted relationship with that observed for SDSS galaxies and find that the model successfully predicts most of the qualitative features seen in the data, but also shows some interesting differences. Specifically, the simulation predicts that the local density around bright red galaxies is a strong increasing function of luminosity, but does not depend much on color at fixed luminosity. Moreover, we show that these trends are due to …
Simulation Of Soft X-Ray Emission Lines From The Missing Baryons, Tt Fang, Rac Croft, Wt Sanders, J Houck, R Dave, N Katz, Dh Weinberg, L Hernquist
Simulation Of Soft X-Ray Emission Lines From The Missing Baryons, Tt Fang, Rac Croft, Wt Sanders, J Houck, R Dave, N Katz, Dh Weinberg, L Hernquist
Astronomy Department Faculty Publication Series
We study the soft X-ray emission (0.1-1 keV) from the warm-hot intergalactic medium (WHIM) in a hydrodynamic simulation of a cold dark matter universe. Our main goal is to investigate how such emission can be explored with a combination of imaging and spectroscopy and to motivate future X-ray missions. We first present high-resolution images of the X-ray emission in several energy bands in which emission from different ion species dominates. We pick three different areas to study the high-resolution spectra of X-rays from the WHIM: (1) a galaxy group, (2) a filament, and (3) an underluminous region. By taking into …