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N. González

Publications and source records attributed to N. González.

4 recordsLinked to original sources

Galaxias de bajo brillo superficial: analogas a los satélites de Andrómeda en Pegasus I?

Here we show the preliminary results of a study where there seems to be a bias effect in the size distributions of the detected low-surface brightness (LSB) galaxies in different environments. In this sense, more distant groups/clusters would lack small effective radius objects, while large systems would not found in the Local Group and nearby environments. While there may be an actual shortage of large LSB galaxies in low-density environments like the Local Group, the non-detection of small (and faint) systems at large distances is clearly a selection effect. As an example, LSB galaxies with similar sizes to those of the satellites of Andromeda in the Local Group, will be certainly missed in a visual identification at the distance of Pegasus I.

astro-ph.GA↗

Propiedades fotométricas de las galaxias enanas de bajo brillo superficial en la zona central del grupo Pegasus I

Here we show the preliminary results of a photometric study of low surface brightness objects with $μ_{g'}~\gtrsim~25$~mag/arcsec$^2$. These objects are present in several fields obtained with GEMINI-GMOS, in the central region of the Pegasus I group. We found that their photometric characteristics are similar to the so-called dwarf spheroidal galaxies or to the ultra low surface brightness galaxies.

astro-ph.GA↗

Study of the chemical composition of high energy cosmic rays using the muon LDF of EAS between $10^{17.25}$ eV and $10^{17.75}$ eV

We explore the feasibility of estimating primary cosmic ray composition at high energies from the study of two parameters of Extensive Air Showers (EAS) at ground and underground level with Monte Carlo simulations using the new EPOS and QGSJETII hadronic models tuned with LHC data. Namely, the slope and density at a given distance of the muon lateral distribution function are analysed in this work. The power to discriminate primary masses is quantified in terms of merit factor for each parameter. The analysis considers three different primary particles (proton, iron and gamma), four different zenith angles (0$^{\circ}$, 15$^{\circ}$, 30$^{\circ}$ and 45$^{\circ}$) and primary energies of $10^{17.25}$ eV, $10^{17.50}$ eV and $10^{17.75}$ eV.

astro-ph.HE↗

The lateral shower age parameter as an estimator of chemical composition

We explore the feasibility of estimating primary cosmic ray composition at ultra high energies from the study of lateral age parameter of Extensive Air Showers (EAS) at ground level. Using different types of lateral distribution functions, we fit the particle density of simulated EAS to find the lateral age parameter. We discuss the chemical composition calculating the merit factor for each parameter distribution. The analysis considers three different primary particles (proton, iron and gamma), four different zenith angles (0°, 15°, 30° and 45°) and three primary energies (10^{17.25} eV, 10^{17.50} eV and 10^{17.75} eV).

astro-ph.HE↗