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Galaxy merger statistics and inferred bulge-to-disk ratios in cosmological SPH simulations
formation spiral elliptical
2014/12/24
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 ...
Systematics in Aggregated Neutrino Fluxes and Flavor Ratios from Gamma-Ray Bursts
Systematics Aggregated Neutrino Fluxes Flavor Ratios Gamma-Ray Bursts
2011/10/20
Gamma-ray burst analyses at neutrino telescopes are typically based on diffuse or stacked (i.e., aggregated) neutrino fluxes, because the number of events expected from a single burst is small. The ag...
The host galaxies and black-hole:galaxy mass ratios of luminous quasars at z~4
galaxies: active – galaxies: fundamental parameters – galaxies: high-redshift –galaxies: photometry – infrared: galaxies – quasars: general
2011/10/8
We present and analyse the deepest, high-quality Ks-band images ever obtained of luminous quasars at z~4, in an attempt to determine the basic properties of their host galaxies less than 1 Gyr after t...
p, He, and C to Fe cosmic-ray primary fluxes in diffusion models: Source and transport signatures on fluxes and ratios
Methods statistical – ISM cosmic rays
2010/11/10
Context. The source spectrum of cosmic rays is not well determined by diffusive shock acceleration models. The prop-agated fluxes of proton, helium, and heavier primary cosmic-ray species (up to Fe) a...
Chemical abundance ratios of galactic globular clusters from modelling integrated light spectroscopy
galactic globular clusters light spectroscopy
2011/1/10
We use our new, flux-calibrated stellar population model of absorption-line indices to derive ages, metallicities, and various element abundance ratios from integrated light spectroscopy of galactic g...
Flux-calibrated stellar population models of Lick absorption-line indices with variable element abundance ratios
Flux-calibrated stellar population models Lick absorption-line indices
2011/1/10
We present new stellar population models of Lick absorption-line indices with variable element abundance ratios. The models are based on our new calibrations of absorption-line indices with stellar pa...
Cosmic Ray e^+/(e^- + e^+) and pbar/p Ratios Explained by an Injection Model Based on Gamma-ray Observations
High Energy Astrophysical Phenomena (astro-ph.HE)
2011/1/6
We present a model of cosmic ray injection into the Galactic space based on recent gamma-ray observations of supernova remnants (SNRs) and pulsar wind nebulae (PWNe) by the Fermi Large Area Telescope ...
The SEGUE Stellar Parameter Pipeline. V. Estimation of Alpha-Element Abundance Ratios From Low-Resolution SDSS/SEGUE Stellar Spectra
Instrumentation and Methods for Astrophysics (astro-ph.IM)
2011/1/5
We present a method for the determination of [alpha/Fe] ratios from low-resolution (R = 2000) SDSS/SEGUE stellar spectra.
PAH and Emission Line Ratios in AGN and Starburst Galaxies
Cosmology and Extragalactic Astrophysics (astro-ph.CO)
2010/12/28
We study the Polycyclic Aromatic Hydrocarbons (PAH) bands, ionic emission lines, and Mid-infrared continuum properties, in a sample of 171 emission line galaxies taken from literature plus 15 new acti...
Statistical universal branching ratios for cosmic ray dissociation, photodissociation, and dissociative recombination of the C(n=2-10), C(n=2-4)H and C3H2 neutral and cationic species
Galaxy Astrophysics (astro-ph.GA)
2010/12/23
Fragmentation branching ratios of electronically excited molecular species are of first importance for the modeling of gas phase interstellar chemistry. Despite experimental and theoretical efforts th...
Emission line ratios from variable velocity jet models
Emission line ratios variable velocity jet models
2009/6/30
Emission line ratios from variable velocity jet models。
Measuring the mass ratios of x-ray transients from the Rotational broadening of the secondary star s spectrum
mass ratios secondary star s spectrum x-ray transients
2009/6/17
Measuring the mass ratios of x-ray transients from the Rotational broadening of the secondary star s spectrum。
HH 111 Line Ratios from STIS Spectra。
Diagnostic determination of ionization and density in stellar jets from line ratios
ionization density line ratios stellar jets
2009/6/10
Diagnostic determination of ionization and density in stellar jets from line ratios。
Using the relative line intensity (I) ratios of the astrophysically im-
portant 518.360 nm, 517.268 nm and 516.732 nm neutral magnesium (Mg I) lines in
the 3p 3Po0;1;2 4s 3S1 transition we have obta...