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Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
The Bar-Halo Interaction - I. From Fundamental Dynamics To Revised N-Body Requirements, Md Weinberg, N Katz
The Bar-Halo Interaction - I. From Fundamental Dynamics To Revised N-Body Requirements, Md Weinberg, N Katz
Astronomy Department Faculty Publication Series
A galaxy remains near equilibrium for most of its history. Only through resonances can non-axisymmetric features, such as spiral arms and bars, exert torques over large scales and change the overall structure of the galaxy. In this paper, we describe the resonant interaction mechanism in detail, derive explicit criteria for the particle number required to simulate these dynamical processes accurately using N-body simulations, and illustrate them with numerical experiments. To do this, we perform a direct numerical solution of perturbation theory, in short, by solving for each orbit in an ensemble and make detailed comparisons with N-body simulations. The criteria …
Multiwavelength Study Of Massive Galaxies At Z Similar To 2. I. Star Formation And Galaxy Growth, E Daddi, M Dickinson, G Morrison, R Chary, A Cimatti, D Elbaz, D Frayer, A Renzini, A Pope, Dm Alexander, Fe Bauer, M Giavalisco, M Huynh, J Kurk, M Mignoli
Multiwavelength Study Of Massive Galaxies At Z Similar To 2. I. Star Formation And Galaxy Growth, E Daddi, M Dickinson, G Morrison, R Chary, A Cimatti, D Elbaz, D Frayer, A Renzini, A Pope, Dm Alexander, Fe Bauer, M Giavalisco, M Huynh, J Kurk, M Mignoli
Astronomy Department Faculty Publication Series
No abstract provided.
The Spatial Clustering Of Mid-Ir Selected Star Forming Galaxies At Z Similar To 1 In The Goods Fields, R Gilli, E Daddi, R Chary, M Dickinson, D Elbaz, M Giavalisco, M Kitzbichler, D Stern, E Vanzella
The Spatial Clustering Of Mid-Ir Selected Star Forming Galaxies At Z Similar To 1 In The Goods Fields, R Gilli, E Daddi, R Chary, M Dickinson, D Elbaz, M Giavalisco, M Kitzbichler, D Stern, E Vanzella
Astronomy Department Faculty Publication Series
We present the first spatial clustering measurements of z~1, 24um-selected, star forming galaxies in the Great Observatories Origins Deep Survey (GOODS). The sample under investigation includes 495 objects in GOODS-South and 811 objects in GOODS-North selected down to flux densities of f_24>20 uJy and z_AB<23.5 mag, for which spectroscopic redshifts are available. The median redshift, IR luminosity and star formation rate (SFR) of the samples are z~0.8, L_IR~4.4 x 10^10 L_sun, and SFR~7.6 M_sun/yr, respectively. We measure the projected correlation function w(r_p) on scales of r_p=0.06-10 h^-1 Mpc, from which we derive a best fit comoving correlation length of r_0 = 4.0 +- 0.4 h^-1 Mpc and slope of gamma=1.5 +- 0.1 for the whole f_24>20uJy sample after combining the two fields. We find indications of a larger correlation length for objects of higher luminosity, with Luminous Infrared Galaxies (LIRGs, L_IR>10^11 L_sun) reaching r_0~5.1 h^-1 Mpc. This would imply that galaxies with larger SFRs are hosted in progressively more massive halos, reaching minimum halo masses of ~3 x …
Accretion, Feedback And Galaxy Bimodality: A Comparison Of The Galics Semi-Analytic Model And Cosmological Sph Simulations, A Cattaneo, J Blaizot, Dh Weinberg, D Keres, S Colombi, R Dave, J Devriendt, B Guiderdoni, N Katz
Accretion, Feedback And Galaxy Bimodality: A Comparison Of The Galics Semi-Analytic Model And Cosmological Sph Simulations, A Cattaneo, J Blaizot, Dh Weinberg, D Keres, S Colombi, R Dave, J Devriendt, B Guiderdoni, N Katz
Astronomy Department Faculty Publication Series
We compare the galaxy population of a smoothed particle hydrodynamics (SPH) simulation to those predicted by the GalICS (Galaxies In Cosmological Simulations) N-body + semi-analytic model and a stripped down version of GalICS that omits the effects of supernova and active galactic nucleus (AGN) feedback. The SPH simulation and the no-feedback GalICS model make similar predictions for the baryonic mass functions of galaxies and for the dependence of these mass functions on environment and redshift. The two methods also make similar predictions for the galaxy content of dark matter haloes as a function of halo mass and for the …
Evidence For A Population Of High-Redshift Submillimeter Galaxies From Interferometric Imaging, Jd Younger, Gg Fazio, Js Huang, Min Yun, Gw Wilson, Mln Ashby, Ma Gurwell, K Lai, Ab Peck, Gr Petitpas, Dj Wilner, D Iono, K Kohno, R Kawabe, Dh Hughes, I Aretxaga, T Webb, A Martinez-Sansigre, S Kim, Ks Scott, J Austermann, T Perera, Jd Lowenthal, E Schinnerer, V Smolcic
Evidence For A Population Of High-Redshift Submillimeter Galaxies From Interferometric Imaging, Jd Younger, Gg Fazio, Js Huang, Min Yun, Gw Wilson, Mln Ashby, Ma Gurwell, K Lai, Ab Peck, Gr Petitpas, Dj Wilner, D Iono, K Kohno, R Kawabe, Dh Hughes, I Aretxaga, T Webb, A Martinez-Sansigre, S Kim, Ks Scott, J Austermann, T Perera, Jd Lowenthal, E Schinnerer, V Smolcic
Astronomy Department Faculty Publication Series
We have used the Submillimeter Array to image a flux-limited sample of seven submillimeter galaxies, selected by the AzTEC camera on the JCMT at 1.1 mm, in the COSMOS field at 890 μ m with ~2'' resolution. All of the sources—two radio-bright and five radio-dim—are detected as single point sources at high significance (>6 σ), with positions accurate to ~0.2'' that enable counterpart identification at other wavelengths observed with similarly high angular resolution. All seven have IRAC counterparts, but only two have secure counterparts in deep HST ACS imaging. As compared to the two radio-bright sources in the sample, …
The Dynamics Of Tidal Tails From Massive Satellites, Jh Choi, Md Weinberg, N Katz
The Dynamics Of Tidal Tails From Massive Satellites, Jh Choi, Md Weinberg, N Katz
Astronomy Department Faculty Publication Series
We investigate the dynamical mechanisms responsible for producing tidal tails from dwarf satellites using N-body simulations. We describe the essential dynamical mechanisms and morphological consequences of tail production in satellites with masses greater than 0.0001 of the host halo virial mass. We identify two important dynamical coconspirators: (1) the points where the attractive force of the host halo and satellite are balanced (X-points) do not occur at equal distances from the satellite centre or at the same equipotential value for massive satellites, breaking the morphological symmetry of the leading and trailing tails and (2) the escaped ejecta in the leading …
Star Formation In Ngc 5194 (M51a). Ii. The Spatially Resolved Star Formation Law, Rc Kennicutt, D Calzetti, F Walter, G Helou, Dj Hollenbach, L Armus, G Bendo, Da Dale, Bt Draine, Cw Engelbracht, Kd Gordon, Mkm Prescott, Mw Regan, Md Thornley, C Bot, E Brinks, E De Blok, D De Mello, M Meyer, J Moustakas, Ej Murphy, K Sheth, Jdt Smith
Star Formation In Ngc 5194 (M51a). Ii. The Spatially Resolved Star Formation Law, Rc Kennicutt, D Calzetti, F Walter, G Helou, Dj Hollenbach, L Armus, G Bendo, Da Dale, Bt Draine, Cw Engelbracht, Kd Gordon, Mkm Prescott, Mw Regan, Md Thornley, C Bot, E Brinks, E De Blok, D De Mello, M Meyer, J Moustakas, Ej Murphy, K Sheth, Jdt Smith
Astronomy Department Faculty Publication Series
We have studied the relationship between the star formation rate (SFR), surface density, and gas surface density in the spiral galaxy M51a (NGC 5194), using multiwavelength data obtained as part of the Spitzer Infrared Nearby Galaxies Survey (SINGS). We introduce a new SFR index based on a linear combination of Hα emission-line and 24 μm continuum luminosities, which provides reliable extinction-corrected ionizing fluxes and SFR densities over a wide range of dust attenuations. The combination of these extinction-corrected SFR densities with aperture synthesis H I and CO maps has allowed us to probe the form of the spatially resolved star …