A new catalog of photometric redshifts in the Hubble Deep Field

Using the newly available infrared images of the Hubble Deep Field in the J, H, and K bands and an optimal photometric method, we have refined a technique to estimate the redshifts of 1067 galaxies. A detailed comparison of our results with the spectroscopic redshifts in those cases where the latter are available shows that this technique gives very good results for bright enough objects (AB(8140) < 26.0). From a study of the distribution of residuals (Dz(rms)/(1+z) ~ 0.1 at all redshifts) we conclude that the observed errors are mainly due to cosmic variance. This very important result allows for the assessment of errors in quantities to be directly or indirectly measured from the catalog. We present some of the statistical properties of the ensemble of galaxies in the catalog, and finish by presenting a list of bright high-redshift (z ~ 5) candidates extracted from our catalog, together with recent spectroscopic redshift determinations confirming that two of them are at z=5.34 and z=5.60.Comment: 28 pages, 12PS+4JPEG figures, aaspp style. Accepted for publication in The Astrophysical Journal. The catalog, together with a clickable map of the HDF, Tables 4 and 5 (HTML, LaTeX or ASCII format), and the figures, are available at http://bat.phys.unsw.edu.au/~fsoto/hdfcat.htm

Galaxy Masses

Galaxy masses play a fundamental role in our understanding of structure formation models. This review addresses the variety and reliability of mass estimators that pertain to stars, gas, and dark matter. The different sections on masses from stellar populations, dynamical masses of gas-rich and gas-poor galaxies, with some attention paid to our Milky Way, and masses from weak and strong lensing methods, all provide review material on galaxy masses in a self-consistent manner.Comment: 145 pages, 28 figures, to appear in Reviews of Modern Physics. Figure 22 is missing here, and Figs. 15, 26-28 are at low resolution. This version has a slightly different title and some typos fixed in Chapter 5. For the full review with figures, please consult: http://www.astro.queensu.ca/~courteau/GalaxyMasses_28apr2014.pd

Structure of Disk Dominated Galaxies I. Bulge/Disk Parameters, Simulations, and Secular Evolution

(Abridged) A robust analysis of galaxy structural parameters, based on the modeling of bulge and disk brightnesses in the BVRH bandpasses, is presented for 121 face-on and moderately inclined late-type spirals. Each surface brightness (SB) profile is decomposed into a sum of a generalized Sersic bulge and an exponential disk. The reliability and limitations of our bulge-to-disk (B/D) decompositions are tested with extensive simulations of galaxy brightness profiles (1D) and images (2D). Galaxy types are divided into 3 classes according to their SB profile shapes; Freeman Type-I and Type-II, and a third ``Transition'' class for galaxies whose profiles change from Type-II in the optical to Type-I in the infrared. We discuss possible interpretations of Freeman Type-II profiles. The Sersic bulge shape parameter for nearby Type-I late-type spirals shows a range between n=0.1-2 but, on average, the underlying surface density profile for the bulge and disk of these galaxies is adequately described by a double-exponential distribution. We confirm a coupling between the bulge and disk with a scale length ratio r_e/h=0.22+/-0.09, or h_bulge/h_disk=0.13+/-0.06 for late-type spirals, in agreement with recent N-body simulations of disk formation and models of secular evolution. This ratio increases from ~0.20 for late-type spirals to ~0.24 for earlier types. The similar scaling relations for early and late-type spirals suggest comparable formation and/or evolution scenarios for disk galaxies of all Hubble types.Comment: 78 pages with 23 embedded color figures + tables of galaxy structural parameters. Accepted for publication in the Astrophysical Journal. The interested reader is strongly encouraged to ignore some of the low res figures within; instead, download the high resolution version from http://www.astro.ubc.ca/people/courteau/public/macarthur02_disks.ps.g

Effective temperature and Gilbert damping of a current-driven localized spin

Starting from a model that consists of a semiclassical spin coupled to two leads we present a microscopic derivation of the Langevin equation for the direction of the spin. For slowly-changing direction it takes on the form of the stochastic Landau-Lifschitz-Gilbert equation. We give expressions for the Gilbert damping parameter and the strength of the fluctuations, including their bias-voltage dependence. At nonzero bias-voltage the fluctuations and damping are not related by the fluctuation-dissipation theorem. We find, however, that in the low-frequency limit it is possible to introduce a voltage-dependent effective temperature that characterizes the fluctuations in the direction of the spin, and its transport-steady-state probability distribution function.Comment: 8 pages, 2 figures. v2: published versio

Exploring the Structure of Distant Galaxies with Adaptive Optics on the Keck-II Telescope

We report on the first observation of cosmologically distant field galaxies with an high order Adaptive Optics (AO) system on an 8-10 meter class telescope. Two galaxies were observed at 1.6 microns at an angular resolution as high as 50 milliarcsec using the AO system on the Keck-II telescope. Radial profiles of both objects are consistent with those of local spiral galaxies and are decomposed into a classic exponential disk and a central bulge. A star-forming cluster or companion galaxy as well as a compact core are detected in one of the galaxies at a redshift of 0.37+/-0.05. We discuss possible explanations for the core including a small bulge, a nuclear starburst, or an active nucleus. The same galaxy shows a peak disk surface brightness that is brighter than local disks of comparable size. These observations demonstrate the power of AO to reveal details of the morphology of distant faint galaxies and to explore galaxy evolution.Comment: 5 pages, Latex, 3 figures. Accepted for publication in P.A.S.

Quantum-Statistical Current Correlations in Multi-Lead Chaotic Cavities

Quantum mechanics requires that identical particles are treated as indistinguishable. This requirement leads to correlations in the fluctuating properties of a system. Theoretical predictions are made for an experiment on a multi-lead chaotic quantum dot which can identify exchange effects in electronic current-current correlations. Interestingly, we find that the ensemble averaged exchange effects are of the order of the channel number, and are insensitive to dephasing.Comment: 4 pages REVTEX, including two figure

Strong Balmer lines in old stellar populations: No need for young ages in ellipticals?

Comparing models of Simple Stellar Populations (SSP) with observed line strengths generally provides a tool to break the age-metallicity degeneracy in elliptical galaxies. Due to the wide range of Balmer line strengths observed, ellipticals have been interpreted to exhibit an appreciable scatter in age. In this paper, we analyze Composite Stellar Population models with a simple mix of an old metal-rich and an old metal-poor component. We show that these models simultaneously produce strong Balmer lines and strong metallic lines without invoking a young population. The key to this result is that our models are based on SSPs that better match the steep increase of Hbeta in metal-poor globular clusters than models in the literature. Hence, the scatter of Hbeta observed in cluster and luminous field elliptical galaxies can be explained by a spread in the metallicity of old stellar populations. We check our model with respect to the so-called G-dwarf problem in ellipticals. For a galaxy subsample covering a large range in UV-V colors we demonstrate that the addition of an old metal-poor subcomponent does not invalidate other observational constraints like colors and the flux in the mid-UV.Comment: Accepted for publication in ApJ Main Journal, 9 pages, 5 figure

Morphology of the 12-micron Seyfert Galaxies: II. Optical and Near-Infrared Image Atlas

We present 263 optical and near-infrared (NIR) images for 42 Seyfert 1s and 48 Seyfert 2s, selected from the Extended 12-micron Galaxy Sample. Elliptically-averaged profiles are derived from the images, and isophotal radii and magnitudes are calculated from these. We also report virtual aperture photometry, that judging from comparison with previous work, is accurate to roughly 0.05mag in the optical, and 0.07mag in the NIR. Our B-band isophotal magnitude and radii, obtained from ellipse fitting, are in good agreement with those of RC3. When compared with the B band, V, I, J, and K isophotal diameters show that the colors in the outer regions of Seyferts are consistent with the colors of normal spirals. Differences in the integrated isophotal colors and comparison with a simple model show that the active nucleus+bulge is stronger and redder in the NIR than in the optical. Finally, roughly estimated Seyfert disk surface brightnesses are significantly brighter in B and K than those in normal spirals of similar morphological type.Comment: 17 pgs including figures; Table 2 is a separate file. Complete Figure 1 is available by contacting the authors. Accepted for publication in ApJ

Relativistic Brueckner-Hartree-Fock calculations with explicit intermediate negative energy states

In a relativistic Brueckner-Hartree-Fock calculation we include explicit negative-energy states in the two-body propagator. This is achieved by using the Gross spectator-equation, modified by medium effects. Qualitatively our results compare well with other RBHF calculations. In some details significant differences occur, e.g, our equation of state is stiffer and the momentum dependence of the self-energy components is stronger than found in a reference calculation without intermediate negative energy states.Comment: 13 pages Revtex, 5 figures included seperatel