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Full-Text Articles in Physical Sciences and Mathematics
The Morphological Diversities Among Star-Forming Galaxies At High Redshifts In The Great Observatories Origins Deep Survey, S Ravindranath, M Giavalisco, Hc Ferguson, C Conselice, N Katz, M Weinberg, J Lotz, M Dickinson, Sm Fall, B Mobasher, C Papovich
The Morphological Diversities Among Star-Forming Galaxies At High Redshifts In The Great Observatories Origins Deep Survey, S Ravindranath, M Giavalisco, Hc Ferguson, C Conselice, N Katz, M Weinberg, J Lotz, M Dickinson, Sm Fall, B Mobasher, C Papovich
Astronomy Department Faculty Publication Series
We used the deep, multiwavelength images obtained by the Great Observatories Origins Deep Survey (GOODS) to identify ~4700 Lyman break galaxies (LBGs) at z > 2.5, and 292 starburst galaxies at z ~ 1.2. We present the results from morphological analysis based on light profile shape and ellipticity for ~1333 of the most luminous LBGs. About 40% of LBGs at z ~ 3 have exponential profiles, ~30% of the galaxies have steep (r1/4-like) profiles, and ~30% of LBGs have multiple cores of disturbed morphologies suggestive of close pairs or mergers. The fraction of spheriod-like LBGs decrease by about 15% from z …
Galaxy Merger Statistics And Inferred Bulge-To-Disk Ratios In Cosmological Sph Simulations, Ah Maller, N Katz, D Keres, R Dave, Dh Weinberg
Galaxy Merger Statistics And Inferred Bulge-To-Disk Ratios In Cosmological Sph Simulations, Ah Maller, N Katz, D Keres, R Dave, Dh Weinberg
Astronomy Department Faculty Publication Series
We construct merger trees for galaxies identified in a cosmological hydrodynamic simulation and use them to characterize predicted merger rates as a function of redshift, galaxy mass, and merger mass ratio. At z = 0.3, we find a mean rate of 0.054 mergers per galaxy per Gyr above a 1 : 2 mass ratio threshold for massive galaxies (baryonic mass above 6.4 × 1010 M), but only 0.018 Gyr-1 for lower mass galaxies. The mass ratio distribution is R for the massive galaxy sample, so high-mass mergers dominate the total merger growth rate. The predicted rates increase …
Probing Galaxy Formation With He Ii Cooling Lines, Yj Yang, Ai Zabludoff, R Dave, Dj Eisenstein, Pa Pinto, N Katz, Dh Weinberg, Ej Barton
Probing Galaxy Formation With He Ii Cooling Lines, Yj Yang, Ai Zabludoff, R Dave, Dj Eisenstein, Pa Pinto, N Katz, Dh Weinberg, Ej Barton
Astronomy Department Faculty Publication Series
Using high-resolution cosmological simulations, we study hydrogen and helium gravitational cooling radiation from gas accretion by young galaxies. We focus on the He II cooling lines, which arise from gas with a different temperature history (Tmax ~ 105 K) than H I line-emitting gas. We examine whether three major atomic cooling lines, H I λ1216, He II λ1640, and He II λ304, are observable, finding that Lyα and He II λ1640 cooling emission at z = 2-3 are potentially detectable with deep narrowband (R > 100) imaging and/or spectroscopy from the ground. While the expected strength of …
On The Origin Of Cold Dark Matter Halo Density Profiles, Y Lu, Hj Mo, N Katz, Md Weinberg
On The Origin Of Cold Dark Matter Halo Density Profiles, Y Lu, Hj Mo, N Katz, Md Weinberg
Astronomy Department Faculty Publication Series
N-body simulations predict that cold dark matter (CDM) halo-assembly occurs in two phases: (i) a fast-accretion phase with a rapidly deepening potential well; and (ii) a slow-accretion phase characterized by a gentle addition of mass to the outer halo with little change in the inner potential well. We demonstrate, using one-dimensional simulations, that this two-phase accretion leads to CDM haloes of the Navarro, Frenk & White (NFW) form and provides physical insight into the properties of the mass-accretion history that influence the final profile. Assuming that the velocities of CDM particles are effectively isotropized by fluctuations in the gravitational potential …
Interferometric 890 Mu M Images Of High-Redshift Submillimeter Galaxies, D Iono, Ab Peck, A Pope, C Borys, D Scott, Dj Wilner, M Gurwell, Ptp Ho, Min Yun, S Matsushita, Gr Petitpas, Js Dunlop, M Elvis, A Blain, E Le Floc'h
Interferometric 890 Mu M Images Of High-Redshift Submillimeter Galaxies, D Iono, Ab Peck, A Pope, C Borys, D Scott, Dj Wilner, M Gurwell, Ptp Ho, Min Yun, S Matsushita, Gr Petitpas, Js Dunlop, M Elvis, A Blain, E Le Floc'h
Astronomy Department Faculty Publication Series
We present high-resolution 890 μm images of two 20 mJy submillimeter galaxies, SMM J123711+622212 and MIPS J142824.0+352619, obtained using the Submillimeter Array (SMA). Using submillimeter interferometric observations with an angular resolution of 25, the coordinates of these high-redshift sources are determined with an accuracy of 02. The new SMA data on SMM J123711+622212 reveal an unresolved submillimeter source offset to the east by 08 from an optical galaxy found in deep HST images, suggesting either a large galaxy with a dusty central region or an interacting galaxy system. The SMA image of hyperluminous (LFIR = 3.2 × 10 …