Browsing by Author "Mesa Delgado, Adal"
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- ItemA consistent spectral model of WR 136 and its associated bubble NGC 6888(2015) Reyes Pérez, J.; Morisset, C.; Peña, M.; Mesa Delgado, Adal
- ItemAnalysis of chemical abundances in planetary nebulae with [wc] central stars : Ii. chemical abundances and the abundance discrepancy factor(2013) García Rojas, Jorge; Peña, Miriam; Morisset, Christophe; Delgado Inglada, Gloria; Mesa Delgado, Adal; Ruiz, María Teresa
- ItemAnalysis of chemical abundances in planetary nebulae with [WC] central stars. I. Line intensities and physical conditions(2012) García-Rojas, J.; Mesa Delgado, Adal
- ItemCarbon and oxygen abundances from recombination lines in low-metallicity star-forming galaxies. Implications for chemical evolution(2014) Esteban, C.; García Rojas, J.; Carigi, L.; Peimbert, M.; Bresolin, F.; López Sánchez, A. R.; Mesa Delgado, Adal
- ItemCarbon and oxygen in H II regions of the Magellanic Clouds : abundance discrepancy and chemical evolutionCarbon and(2017) Cipriano, L. Toribio San; Domínguez-Guzmán, G.; Esteban, C.; García-Rojas, J.; Mesa Delgado, Adal; Bresolin, F.; Rodríguez, M.; Simón-Díaz, S.
- ItemChemical abundances in Orion protoplanetary discs: integral field spectroscopy and photoevaporation models of HST 10(2013) Tsamis, Y.; Mesa Delgado, Adal
- ItemDeep high spectral resolution spectroscopy and chemical composition of ionized nebulae(2014) Esteban, C.; Mesa Delgado, AdalHigh spectral resolution spectroscopy has proved to be very useful for the advancement of chemical abundances studies in photoionized nebulae, such as H II regions and planetary nebulae (PNe). Classical analyses make use of the intensity of bright collisionally excited lines (CELs), which have a strong dependence on the electron temperature and density. By using high resolution spectrophotometric data, our group has led the determination of chemical abundances of some heavy element ions, mainly O++, O+, and C++ from faint recombination lines (RLs), allowing us to deblend them from other nearby emission lines or sky features. The importance of these lines is that their emissivity depends weakly on the temperature and density structure of the gas. The unresolved issue in this field is that recombination lines of heavy element ions give abundances that are about 2–3 times higher than those derived from CELs – in H II regions – for the same ion, and can even be a factor of 70 times higher in some PNe. This uncertainty puts into doubt the validity of face values of metallicity that we use as representative not only for ionized nebulae in the Local Universe, but also for star-forming dwarf and spiral galaxies at different redshifts. Additionally, high-resolution data can allow us to detect and deblend faint lines of neutron capture element ions in PNe. This information would introduce further restrictions to evolution models of AGBs and would help to quantify the chemical enrichment in s-elements produced by low and intermediate mass stars. The availability of an échelle spectrograph at the E-ELT will be of paramount interest to: (a) extend the studies of heavyelement recombination lines to low metallicity objects, (b) to extend abundance determinations of s-elements to planetary nebulae in the extragalactic domain and to bright Galactic and extragalactic H II regions.
- ItemExploring the effects of high-velocity flows in abundance determinations in H ii regions: bidimensional spectroscopy of HH 204 in the Orion nebula(2012) Nuñez, M.; Mesa Delgado, Adal
- ItemIntegral field spectroscopy of selected areas of the Bright bar and Orion-S cloud in the Orion nebula(2011) Mesa Delgado, Adal
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- ItemNeutron-capture element abundances in the planetary nebula NGC 5315 from deep optical and near-infrared spectrophotometry(2017) Mesa Delgado, Adal; Madonna, S.; García, J.; Sterling, N.; Delgado, G.; Luridiana, V.; Roederer, I.; Mashburn, A.
- ItemNGC 2579 and the carbon and oxygen abundance gradients beyond the solar circle(2013) Esteban, C.; Mesa Delgado, Adal
- ItemThe chemical composition of Galactic ring nebulae around massive stars(2016) Esteban, C.; Mesa Delgado, Adal; Morisset, C.; García Rojas, J.
- ItemThe Fe/Ni ratio in ionized nebulae : clues on dust depletion patterns(2016) Delgado-Inglada, G.; Mesa Delgado, Adal; García-Rojas, J.; Rodríguez, M.; Esteban, C.
- ItemThe integral field view of the orion nebula(2014) Mesa Delgado, Adal
- ItemTHE trace of the CNO cycle in the ring nebula NGC 6888(2014) Mesa Delgado, Adal