39 research outputs found
Blue compact dwarf galaxies with nitrogen overabundance: a view from integral field spectroscopy
This is an electronic version of the poster presented at the IX Scientific Meeting of the Spanish Astronomical Society (SEA), held on September 13-17, 2010, in Madrid.The summary of the poster appears in Zapatero Osorio, M.R. et al. (eds.). Highlights of Spanish Astrophysics VI. Proceedings of the IX Scientific Meeting of the Spanish Astronomical Society (SEA), held on September 13-17, 2010, in Madrid. Barcelona: Sociedad Española de AstronomĂa, 2011. 39
Integral field spectroscopy of H II region complexes: the outer disc of NGC 6946
This is an electronic version of an article published in Monthly Notices of the Royal Astronomical Society. GarcĂa-Benito, R., DĂaz, A., HĂ€gele, G.F., PĂ©rez-Montero, E., LĂłpez, J., VĂlchez, J.M., PĂ©rez, E., Terlevich, E., Terlevich, R., D. Rosa-GonzĂĄlez. Integral field spectroscopy of H II region complexes: the outer disc of NGC 6946. Monthly Notices of the Royal Astronomical Society 408 (2010): 2234-225
Mass-metallicity relation explored with CALIFA I. Is there a dependence on the star-formation rate?
We studied the global and local M-Z relation based on the first data available from the CALIFA survey (150 galaxies). This survey provides
integral field spectroscopy of the complete optical extent of each galaxy (up to 2â3 effective radii), with a resolution high enough to separate
individual Hii regions and/or aggregations. About 3000 individual Hii regions have been detected. The spectra cover the wavelength range
between [OII]3727 and [SII]6731, with a sufficient signal-to-noise ratio to derive the oxygen abundance and star-formation rate associated with
each region. In addition, we computed the integrated and spatially resolved stellar masses (and surface densities) based on SDSS photometric data.
We explore the relations between the stellar mass, oxygen abundance and star-formation rate using this dataset.
We derive a tight relation between the integrated stellar mass and the gas-phase abundance, with a dispersion lower than the one already reported
in the literature (ÏÎlog (O/H) = 0.07 dex). Indeed, this dispersion is only slightly higher than the typical error derived for our oxygen abundances.
However, we found no secondary relation with the star-formation rate other than the one induced by the primary relation of this quantity with
the stellar mass. The analysis for our sample of âŒ3000 individual Hii regions confirms (i) a local mass-metallicity relation and (ii) the lack of a
secondary relation with the star-formation rate. The same analysis was performed with similar results for the specific star-formation rate.
Our results agree with the scenario in which gas recycling in galaxies, both locally and globally, is much faster than other typical timescales, such
like that of gas accretion by inflow and/or metal loss due to outflows. In essence, late-type/disk-dominated galaxies seem to be in a quasi-steady
situation, with a behavior similar to the one expected from an instantaneous recycling/closed-box model.Nacional de InvestigaciĂłn y Desarrollo funding programs of the Spanish Ministerio de Ciencia e InnovaciĂłn
AYA2010-22111-C03-03
AYA2010-10904ERamon y Cajal project of the spanish Ministerio de EconomĂa y Competitividad
RyC-2011-07590Academy of Sciences of the Czech Republic (ASCR Internal support program of international cooperation projects-PIPPMS)
M100031241
M100031201Czech Republic program for the long-term development of the research institution
RVO67985815Plan Nacional de InvestigaciĂłn y Desarrollo funding program
AYA2010-15081Consejo Nacional de Ciencia y TecnologĂa (CONACyT)Spanish grant
AYA2010-15169Junta de AndalucĂa
TIC114Excellence Project
P08-TIC-03531Consejo Superior de Investigaciones CientĂficas (CSIC)Junta para la AmpliaciĂłn de EstudiosEuropean Social Fund (ESF)spanish programme of International Campus of Excellence MoncloaSpanish PNAYA
AYA2010-21887Spanish Government
CSD2006-00070
AYA2012-38491-C02-02Junta de AndalucĂa
TIC114Autonomic Government of Andalusia
P08-TIC-4075
TIC-126CienciaPortuguese Foundation for Science and TechnologyEuropean Commission
European Commission Joint Research Centre
European Social Fund (ESF)Portuguese Foundation for Science and Technology
SFRH/BPD/66958/2009National Science Foundation (NSF
MEGARA detector test bench at LICA-UCM
LICA (Laboratorio de InstrumentaciŽon CientŽıfica Avanzada) is an initiative of the Campus de Excelencia Internacional of UCM. Among the facilities within LICA, a new laboratory has been assigned to MEGARA project for subsystem tests and AIV. This paper presents the current facilities installed at LICA for detector characterization, which will be used to test and characterize MEGARA detectors
MEGARA cryogenic system
MEGARA (Multi EspectrĂłgrafo en GTC de Alta ResoluciĂłn para AstronomĂa) is the new integral field unit (IFU) and multi-object spectrograph (MOS) instrument for the Gran Telescopio Canarias (GTC). The selected cryogenic device to harbor the CCD detector for the MEGARA spectrograph is a liquid nitrogen open-cycle cryostat. The LN2 open-cycle cryostat is a custom made product which has been designed by the INAOE astronomical instrumentation group. The proposed cryostat offers modular stages for easy assembly and testing whilst also allowing future modifications to accommodate the required CCDs, electronics and optics
InnovaciĂłn y estrategias de intervenciĂłn en acoso escolar
Los problemas de convivencia escolar, violencia escolar, bullying y cyberbullying, en los centros españoles son una realidad y, por tanto, es necesario que los futuros docentes cuenten con estrategias especĂficas para el abordaje de estas situaciones cuando se enfrenten a la realidad de las aulas. En este manual, profesionales del ĂĄrea de la convivencia escolar presentan las actuaciones, programas y herramientas disponibles que en estos momentos se estĂĄn poniendo en prĂĄctica en los centros escolares con resultados positivos. AsĂ, se pretende ampliar el conocimiento teĂłrico-prĂĄctico en el ĂĄmbito de la convivencia, gestiĂłn de conflictos y violencia escolar.EducaciĂłnPsicologĂ
On the spectroscopic properties of star-forming dwarf galaxies in different environments
A study is presented on the spectroscopic properties of a sample of star-forming dwarf galaxies in extreme density environments, as part of an ongoing project intended to evaluate the influence of the environment on the evolution of dwarf galaxies. Subsets of dwarf galaxies in nearby voids, and in the field of the local supercluster have been selected to characterize lower density regions. Conversely, higher density environments have been characterized choosing a subset of galaxies in the direction of the core of the Virgo Cluster, as well as an isolated clump of galaxies. Our findings indicate that, overall, the spectra of those star-forming dwarf galaxies located in low-density regions tend to present higher excitations and ionization parameters, higher HÎČ equivalent widths, and larger total HÎČ luminosities than similar objects located in higher density environments. At the same time, only marginal evidence may be found supporting a trend between the gas metallicity and the density of the environment. The general metallicity-luminosity relation for dwarf galaxies appears to be followed by most galaxies in the sample. An analysis of the spectroscopic ratios of the galaxies using recent evolutionary models of giant H II regions suggests a mixed star-formation history for most of the Virgo star-forming dwarfs, requiring continuous star formation in addition to some currently observable bursts. © 1995 American Astronomical Society
Avance al Estudio del Arte Parietal PaleolĂtico de la cueva de la Motilla (CĂĄdiz)
Se halla el cerro de La Motilla en los relieves orientales de la provincia de CĂĄdiz, en su lĂmite con la de MĂĄlaga con la que comparte una vasta red subterrĂĄnea de cinco kilĂłmetros de desarrollo en varios niveles, algunos de los cuales aĂșn permanecen activos. A su estudio venimos prestando atenciĂłn desde 1974 (Santiago 1976, 1980a, 1980b) y en uno de cuyos pisos superiores, hoy fĂłsil, conocido como Cueva de la Motilla, pusimos de manifiesto en su vestĂbulo, ya en 1975, la presencia de enterramientos del NeolĂtico final, de niveles de habitat e inhumaciones calcolĂticas y testimonios de ocupaciones esporĂĄdicas tardĂas de menor interĂ©s (Santiago 1983)
The chemical composition of H II regions in the outer Galaxy
New spectroscopic observations, including the optical and near-infrared ranges, have been obtained for a sample of H II regions located towards the Galactic anticentre. The sample includes H II regions with known galactocentric distances, their ionizing stars having been clearly identified from previous work. The spectra correspond to low-to-intermediate excitation nebulae, ionized by one/few late O/ early B star(s). The global parameters of the regions, as well as their physical parameters such as electron density and temperature, are presented. Abundances have been computed using direct (spectroscopic) determinations of the electron temperature for some of the objects or alternatively assuming an adopted electron temperature derived from photoionization model fitting. Overall, the data appear to show a substantially flat gradient for the nitrogen abundance, going up to 18 kpc of galactocentric distance, as well as a mild gradient, if any, for oxygen. The data points for sulphur, although less numerous, give abundances which are consistent with the behaviour observed for the other elements. The N/O ratio also presents a very flat gradient across the outer Galaxy, with a value similar to the one derived from observations of optical emission lines of H II regions in the solar neighbourhood