Subvenciones relacionadas:
General
Las estrellas de masa baja e intermedia (M < 8 masas solares, Ms) representan la mayoría de estrellas en el Cosmos y terminan sus vidas en la Rama Asintótica de las Gigantes (AGB) - justo antes de formar Nebulosas Planetarias (NPs) - cuando experimentan procesos nucleosintéticos y moleculares complejos. Las estrellas AGB son importantes contribuyentes al enriquecimiento del medio interestelar, donde nacen nuevas estrellas y planetas (incluyendo nuestro propio Sistema Solar Temprano, SST) y a la evolución química de sistemas estelares como cúmulos globulares (CGs) y galaxias. En particular, las AGBs más masivas (M > 4-5 Ms) sintetizan (radio)isótopos muy diferentes de los formados por AGBs menos masivas y explosiones de Supernova debido a los diferentes mecanismos de nucleosíntesis. Las estrellas evolucionadas en la fase de transición entre AGBs y NPs también forman diversos compuestos orgánicos como PAHs y nanoestructuras moleculares de fullereno y grafeno, siendo un maravilloso laboratorio Astroquímico. Colaboraciones astronómicas punteras como SDSS-IV/APOGEE-2 y el próximo telescopio espacial James Webb representan un paso fundamental para entender la nucleosíntesis y los procesos moleculares en estrellas evolucionadas. Se pretende explorar la nucleosíntesis de (radio)isótopos ligeros/pesados en estrellas AGB y como éstas contribuyen a la radioactividad del SST así como a la formación/evolución de CGs y galaxias. También se pretende entender el proceso de formación "top-down" de nanoestructuras moleculares de fullereno y grafeno en estrellas evolucionadas. Finalmente, se pretende realizar minería de datos obtenidos con el satélite Gaia, para estudiar la fase evolutiva AGB-NP, y además utilizar el telescopio espacial GALEX para descubrir estrellas binarias en NPs Galácticas.
Miembros
Resultados
1. Durante 2020, se han publicado 37 artículos en revistas astronómicas internacionales con referee de alto impacto (incluyendo un review invitado), así como 2 artículos en la revista de Química-Física FNCN.
2. Se han descubierto, por primera vez, estrellas muy ricas en fósforo y cuyo patrón químico no es predicho por ninguna teoría actual de nucleosíntesis estelar.
3. Se ha demostrado que las estrellas ricas en fósforo representan un nuevo sitio estelar para la formación de elementos muy pesados, con importantes implicaciones para la evolución química de nuestra Galaxia.
Actividad científica
Publicaciones relacionadas
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12C/13C isotopic ratios in red-giant stars of the open cluster NGC 6791Carbon isotope ratios, along with carbon and nitrogen abundances, are derived in a sample of 11 red-giant members of one of the most metal-rich clusters in the Milky Way, NGC 6791. The selected red-giants have a mean metallicity and standard deviation of [Fe/H] = +0.39 ± 0.06 (Cunha et al. 2015). We used high-resolution H-band spectra obtained bySzigeti, L. et al.
Fecha de publicación:
32018 -
The interaction of the halo around the butterfly planetary nebula NGC 650-1 with the interstellar mediumWith its bright and wide equatorial waist seen almost edge-on (`the butterfly body') and the faint and broad bipolar extensions (`the butterfly wings'), NGC 650-1 is the archetypical example of bipolar planetary nebula (PN) with butterfly morphology. We present here deep high-resolution broad- and narrow-band optical images that expose the rich andRamos-Larios, G. et al.
Fecha de publicación:
32018 -
The First APOKASC Catalog of Kepler Dwarf and Subgiant StarsWe present the first APOKASC catalog of spectroscopic and asteroseismic data for dwarfs and subgiants. Asteroseismic data for our sample of 415 objects have been obtained by the Kepler mission in short (58.5 s) cadence, and light curves span from 30 up to more than 1000 days. The spectroscopic parameters are based on spectra taken as part of theSerenelli, A. et al.
Fecha de publicación:
122017 -
The 13th Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey Mapping Nearby Galaxies at Apache Point ObservatoryThe fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in 2014 July. It pursues three core programs: the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2), Mapping Nearby Galaxies at APO (MaNGA), and the Extended Baryon Oscillation Spectroscopic Survey (eBOSS). As well as its core program, eBOSSAlbareti, F. D. et al.
Fecha de publicación:
122017 -
C70 Fullerene charge-transfer interaction with alkylnaphthalenes, pinenes, and a dieneAlkylnaphthalenes are not able to form Diels-Alder adducts with C70 fullerene but selected alkylnaphthalenes are able to yield weak charge-transfer complexes (CTC) with C70. More in detail, 1-methylnaphthalene, 2-ethylnaphthalene, and pure naphthalene are not able to produce neither Diels-Alder adducts with C70 fullerene nor CTC. Instead, 1,4García-Hernández, D. A. et al.
Fecha de publicación:
52017 -
Charge-transfer interaction between C60 fullerene and alkylnaphthalenesA series of alkylnaphthalenes, namely 1,4-dimethylnaphthalene, 2,6-diethylnaphthalene, 2-ethylnaphthalene and pure naphthalene are not able to form Diels-Alder adducts with C60 fullerene but produce a series of 1:1 charge-transfer complexes (CTC) where the aromatic compounds act as donor and C60 as acceptor. The spectrophotometric analysis of theseGarcía-Hernández, D. A. et al.
Fecha de publicación:
12017 -
Target Selection for the SDSS-IV APOGEE-2 SurveyAPOGEE-2 is a high-resolution, near-infrared spectroscopic survey observing ∼3 × 105 stars across the entire sky. It is the successor to APOGEE and is part of the Sloan Digital Sky Survey IV (SDSS-IV). APOGEE-2 is expanding on APOGEE’s goals of addressing critical questions of stellar astrophysics, stellar populations, and Galactic chemodynamicalZasowski, G. et al.
Fecha de publicación:
112017 -
Rubidium and zirconium abundances in massive Galactic asymptotic giant branch stars revisitedContext. Luminous Galactic OH/IR stars have been identified as massive (>4-5 M⊙) asymptotic giant branch (AGB) stars experiencing hot bottom burning and Li production. Their Rb abundances and [Rb/Zr] ratios, as derived from classical hydrostatic model atmospheres, are significantly higher than predictions from AGB nucleosynthesis models, posing aPérez-Mesa, V. et al.
Fecha de publicación:
92017 -
Adding the s-Process Element Cerium to the APOGEE Survey: Identification and Characterization of Ce ii Lines in the H-band Spectral WindowNine Ce ii lines have been identified and characterized within the spectral window observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey (between λ1.51 and 1.69 μm). At solar metallicities, cerium is an element that is produced predominantly as a result of the slow capture of neutrons (the s-process) duringCunha, K.a et al.
Fecha de publicación:
82017 -
APOGEE Chemical Abundances of the Sagittarius Dwarf GalaxyThe Apache Point Observatory Galactic Evolution Experiment provides the opportunity of measuring elemental abundances for C, N, O, Na, Mg, Al, Si, P, K, Ca, V, Cr, Mn, Fe, Co, and Ni in vast numbers of stars. We analyze thechemical-abundance patterns of these elements for 158 red giant stars belonging to the Sagittarius dwarf galaxy (Sgr). This isHasselquist, S. et al.
Fecha de publicación:
82017 -
The Apache Point Observatory Galactic Evolution Experiment (APOGEE)The Apache Point Observatory Galactic Evolution Experiment (APOGEE), one of the programs in the Sloan Digital Sky Survey III (SDSS-III), has now completed its systematic, homogeneous spectroscopic survey sampling all major populations of the Milky Way. After a three-year observing campaign on the Sloan 2.5 m Telescope, APOGEE has collected a halfMajewski, S. R. et al.
Fecha de publicación:
92017 -
Atypical Mg-poor Milky Way Field Stars with Globular Cluster Second-generation-like Chemical PatternsWe report the peculiar chemical abundance patterns of 11 atypical Milky Way (MW) field red giant stars observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE). These atypical giants exhibit strong Al and N enhancements accompanied by C and Mg depletions, strikingly similar to those observed in the so-called second-generationFernández-Trincado, J. G. et al.
Fecha de publicación:
92017 -
The evolution of Galactic planetary nebula progenitors through the comparison of their nebular abundances with AGB yieldsWe study the chemical abundances of a wide sample of 142 Galactic planetary nebulae (PNe) with good-quality observations, for which the abundances have been derived more or less homogeneously, thus allowing a reasonable comparison with stellar models. The goal is the determination of mass, chemical composition and formation epoch of theirGarcía-Hernández, D. A. et al.
Fecha de publicación:
112017 -
Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant UniverseWe describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at ApacheMao, Shude et al.
Fecha de publicación:
72017 -
The Correlation between Mixing Length and Metallicity on the Giant Branch: Implications for Ages in the Gaia EraIn the updated APOGEE-Kepler catalog, we have asteroseismic and spectroscopic data for over 3000 first ascent red giants. Given the size and accuracy of this sample, these data offer an unprecedented test of the accuracy of stellar models on the post-main-sequence. When we compare these data to theoretical predictions, we find a metallicityTayar, Jamie et al.
Fecha de publicación:
52017 -
Asymptotic giant branch and super-asymptotic giant branch stars: modelling dust production at solar metallicityWe present dust yields for asymptotic giant branch (AGB) and super-asymptotic giant branch (SAGB) stars of solar metallicity. Stars with initial mass 1.5 M⊙ ≤ Mini ≤ 3 M⊙ reach the carbon star stage during the AGB phase and produce mainly solid carbon and SiC. The size and the amount of the carbon particles formed follows a positive trend with theDell'Agli, F. et al.
Fecha de publicación:
62017 -
Red giants observed by CoRoT and APOGEE: The evolution of the Milky Way's radial metallicity gradientUsing combined asteroseismic and spectroscopic observations of 418 red-giant stars close to the Galactic disc plane (6 kpc RGal ≲ 13 kpc, | ZGal| 0.3 kpc), we measure the age dependence of the radial metallicity distribution in the Milky Way's thin disc over cosmic time. The slope of the radial iron gradient of the young red-giant population (-0Anders, F. et al.
Fecha de publicación:
32017 -
Two groups of red giants with distinct chemical abundances in the bulge globular cluster NGC 6553 through the eyes of APOGEEMultiple populations revealed in globular clusters (GCs) are important windows to the formation and evolution of these stellar systems. The metal-rich GCs in the Galactic bulge are an indispensable part of this picture, but the high optical extinction in this region has prevented extensive research. In this work, we use the high-resolution nearTang, B. et al.
Fecha de publicación:
22017 -
Chemical tagging with APOGEE: discovery of a large population of N-rich stars in the inner GalaxyFormation of globular clusters (GCs), the Galactic bulge, or galaxy bulges in general is an important unsolved problem in Galactic astronomy. Homogeneous infrared observations of large samples of stars belonging to GCs and the Galactic bulge field are one of the best ways to study these problems. We report the discovery by APOGEE (Apache PointSchiavon, R. P. et al.
Fecha de publicación:
22017 -
Chemical Abundances of M-dwarfs from the APOGEE Survey. I. The Exoplanet Hosting Stars Kepler-138 and Kepler-186We report the first detailed chemical abundance analysis of the exoplanet-hosting M-dwarf stars Kepler-138 and Kepler-186 from the analysis of high-resolution (R ∼ 22,500) H-band spectra from the SDSS-IV–APOGEE survey. Chemical abundances of 13 elements—C, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, and Fe—are extracted from the APOGEE spectra ofSouto, D. et al.
Fecha de publicación:
22017