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The Structure of Classical Bulges and Pseudobulges: the Link Between Pseudobulges and SÉRSIC Index
Drory, Niv; Fisher, David B.
In this paper, we study the properties of pseudobulges (bulges that appear similar to disk galaxies) and classical bulges (bulges which appear similar to E-type galaxies) in bulge-disk decompositions. We show that the distribution of bulge Sérsic indices, nb , is bimodal, and this bimodality correlates with the morphology of the bulge. …
Cosmic Variance and Its Effect on the Luminosity Function Determination in Deep High-z Surveys
Trenti, M.; Stiavelli, M.
We study cosmic variance in deep high-redshift surveys and its influence on the determination of the luminosity function for high-redshift galaxies. For several survey geometries relevant for Hubble Space Telescope (HST) and James Webb Space Telescope (JWST) instruments, we characterize the distribution of the galaxy number counts. This is obtaine…
The c2d Spitzer Spectroscopic Survey of Ices around Low-Mass Young Stellar Objects. I. H2O and the 5-8 µm Bands
Augereau, J. -C.; Stapelfeldt, K. R.; van Dishoeck, E. F. +23 more
To study the physical and chemical evolution of ices in solar-mass systems, a spectral survey is conducted of a sample of 41 low-luminosity YSOs (L ~ 0.1-10 L⊙) using 3-38 µm Spitzer and ground-based spectra. The sample is complemented with previously published Spitzer spectra of background stars and with ISO spectra of well-studi…
The great observatories origins deep survey. VLT/FORS2 spectroscopy in the GOODS-South field: Part III
Popesso, P.; Cesarsky, C.; Stern, D. +15 more
Aims:We present the full data set of the spectroscopic campaign of the ESO/GOODS program in the GOODS-South field, obtained with the FORS2 spectrograph at the ESO/VLT.
Methods: Objects were selected as candidates for VLT/FORS2 observations primarily based on the expectation that the detection and measurement of their spectral features would be…
Multi-instrument analysis of electron populations in Saturn's magnetosphere
Schippers, P.; André, N.; Gurnett, D. A. +10 more
We analyze the radial distribution of electron populations inside 20 Rs in Saturn's magnetosphere, and we calculate moments for these populations by a forward modeling method using composite spectra produced by the CAPS/ELS (0.6 eV to 26 keV) and the MIMI/LEMMS (15 keV to 10 MeV) instruments on board Cassini. We first calculate and harm…
Evidence for powerful AGN winds at high redshift: dynamics of galactic outflows in radio galaxies during the ``Quasar Era''
De Breuck, C.; van Breugel, W.; Lehnert, M. D. +2 more
AGN feedback now appears as an attractive mechanism to resolve some of the outstanding problems with the “standard” cosmological models, in particular those related to massive galaxies. At low redshift, evidence is growing that gas cooling and star formation may be efficiently suppressed by mechanical energy input from radio sources. To directly c…
The ACS Virgo Cluster Survey. XV. The Formation Efficiencies of Globular Clusters in Early-Type Galaxies: The Effects of Mass and Environment
Jordán, Andrés; Tonry, John L.; Côté, Patrick +8 more
The fraction of stellar mass contained in globular clusters (GCs), also measured by number as the specific frequency, is a fundamental quantity that reflects both a galaxy's early star formation and its entire merging history. We present specific frequencies, luminosities, and mass fractions for the globular cluster systems of 100 early-type galax…
UV Excess Measures of Accretion onto Young Very Low Mass Stars and Brown Dwarfs
Herczeg, Gregory J.; Hillenbrand, Lynne A.
Low-resolution spectra from 3000 to 9000 Å of young low-mass stars and brown dwarfs were obtained with LRIS on Keck I. The excess UV and optical emission arising in the Balmer and Paschen continua yields mass accretion rates ranging from 2 × 10-12 to 10-8 M⊙ yr-1. These results are compared with HST STIS…
The Pulsating White Dwarf Stars
Fontaine, G.; Brassard, P.
We present a summary of what is currently known about the three distinct families of isolated pulsating white dwarfs. These are the GW Vir stars (He/C/O-atmosphere stars with Teff ≃ 120,000 K), the V777 Her stars (He-atmosphere, Teff ≃ 25,000 K), and the ZZ Ceti stars (H-atmosphere, Teff ≃ 12,000 K), all showing mu…
The Initial-Final Mass Relation: Direct Constraints at the Low-Mass End
Kelson, Daniel D.; Rich, R. Michael; Hansen, Brad M. S. +3 more
The initial-final mass relation represents a mapping between the mass of a white dwarf remnant and the mass that the hydrogen-burning main-sequence star that created it once had. The empirical relation thus far has been constrained using a sample of ~40 stars in young open clusters, ranging in initial mass from ~2.75 to 7 M⊙, and shows …