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
-
The 16th Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS SpectraThis paper documents the 16th data release (DR16) from the Sloan Digital Sky Surveys (SDSS), the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of data from the Southern Hemisphere survey of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2); new data from APOGEE-2 North are also includedAhumada, Romina et al.
Fecha de publicación:
72020 -
The SDSS/APOGEE catalogue of HgMn starsWe report on H-band spectra of chemically peculiar Mercury-Manganese (HgMn) stars obtained via the SDSS/APOGEE survey. As opposed to other varieties of chemically peculiar stars such as classical Ap/Bp stars, HgMn stars lack strong magnetic fields and are defined by extreme overabundances of Mn, Hg, and other heavy elements. A satisfactoryChojnowski, S. Drew et al.
Fecha de publicación:
62020 -
From the bulge to the outer disc: StarHorse stellar parameters, distances, and extinctions for stars in APOGEE DR16 and other spectroscopic surveysWe combine high-resolution spectroscopic data from APOGEE-2 survey Data Release 16 (DR16) with broad-band photometric data from several sources as well as parallaxes from Gaia Data Release 2 (DR2). Using the Bayesian isochrone-fitting code StarHorse, we derived the distances, extinctions, and astrophysical parameters for around 388 815 APOGEE starsQueiroz, A. B. A. et al.
Fecha de publicación:
62020 -
A theoretical investigation of the possible detection of C24 in spaceAstronomical infrared spectral features at ~6.6, 9.8 and 20 micronm have recently been suggested as being due to the planar graphene form of C24 carbon cluster. Here we report density functional theory and coupled cluster calculations on wavefunctions stability, relative energies, and infrared spectra of four different types of C24 isomersSadjadi, SeyedAbdolreza et al.
Fecha de publicación:
82020 -
Detection of CH<SUP>+</SUP>, CH and H<SUB>2</SUB> Molecules in the Young Planetary Nebula IC 4997We have detected CH + and CH molecular absorption lines from the youngcompact planetary nebula IC 4997 from high resolution optical spectra. A high-resolution infra-red (H and K bands) spectrum provides detection of H 2 emission lines among many other lines. The H 2 lines provide an excitation temperature of 2100 K which may result from UVRao, N. Kameswara et al.
Fecha de publicación:
72020 -
The Lazy Giants: APOGEE Abundances Reveal Low Star Formation Efficiencies in the Magellanic CloudsWe report the first APOGEE metallicities and α-element abundances measured for 3600 red giant stars spanning a large radial range of both the Large (LMC) and Small Magellanic Clouds, the largest Milky Way (MW) dwarf galaxies. Our sample is an order of magnitude larger than that of previous studies and extends to much larger radial distances. TheseNidever, David L. et al.
Fecha de publicación:
62020 -
Close Binary Companions to APOGEE DR16 Stars: 20,000 Binary-star Systems Across the Color-Magnitude DiagramMany problems in contemporary astrophysics—from understanding the formation of black holes to untangling the chemical evolution of galaxies—rely on knowledge about binary stars. This, in turn, depends on the discovery and characterization of binary companions for large numbers of different kinds of stars in different chemical and dynamicalPrice-Whelan, Adrian M. et al.
Fecha de publicación:
52020 -
Petroleum, coal and other organics in spaceThe petroleum and coal models of the unidentified infrared emissions (UIE), sometimes referred also as unidentified infrared bands (UIBs) has been reviewed mainly based on the work of the authors with the inclusion of unpublished results. It is shown that the petroleum and coal model of the UIE converges and merges quite well with the MAON (MixedCataldo, Franco et al.
Fecha de publicación:
52020 -
Spectral Classification of B Stars: The Empirical Sequence Using SDSS-IV/APOGEE Near-IR DataWe present a semi-empirical spectral classification scheme for normal B-type stars using near-infrared (NIR) spectra (1.5-1.7 μm) from the Sloan Digital Sky Survey Apache Point Observatory Galaxy Evolution Experiment (APOGEE2)-N data release 14 (DR14) database. The main motivation for working with B-type stars is their importance in the evolutionRamírez-Preciado, Valeria G. et al.
Fecha de publicación:
52020 -
Identification of a Group III CEMP-no Star in the Dwarf Spheroidal Galaxy Canes Venatici ICEMP-no stars, a subclass of carbon-enhanced metal-poor (CEMP) stars, are one of the most significant stellar populations in galactic archeology, because they dominate the low end of the metallicity distribution function, providing information on the early star formation and chemical-evolution history of the Milky Way and its satellite galaxiesYoon, Jinmi et al.
Fecha de publicación:
52020 -
[Li@C60]PF6: Infrared spectra from 90K to 523K; Determination of the molar extinction coefficients and integrated molar absorptivityGarcía-Hernández, D. A. et al.
Fecha de publicación:
62020 -
The age-chemical abundance structure of the Galaxy I: evidence for a late-accretion event in the outer disc at z ∼ 0.6We investigate the age-chemical abundance structure of the outer Galactic disc at a galactocentric distance of r > 10 kpc as recently revealed by the SDSS/APOGEE survey. Two sequences are present in the [α/Fe]-[Fe/H] plane with systematically different stellar ages. Surprisingly, the young sequence is less metal rich, suggesting a recent dilutionLian, Jianhui et al.
Fecha de publicación:
42020 -
The Open Cluster Chemical Abundances and Mapping Survey. IV. Abundances for 128 Open Clusters Using SDSS/APOGEE DR16The Open Cluster Chemical Abundances and Mapping (OCCAM) survey aims to constrain key Galactic dynamical and chemical evolution parameters by the construction of a large, comprehensive, uniform, infrared-based spectroscopic data set of hundreds of open clusters. This fourth contribution from the OCCAM survey presents analysis using Sloan DigitalDonor, John et al.
Fecha de publicación:
52020 -
The chemical compositions of accreted and in situ galactic globular clusters according to SDSS/APOGEEStudies of the kinematics and chemical compositions of Galactic globular clusters (GCs) enable the reconstruction of the history of star formation, chemical evolution, and mass assembly of the Galaxy. Using the latest data release (DR16) of the SDSS/APOGEE survey, we identify 3090 stars associated with 46 GCs. Using a previously defined kinematicHorta, Danny et al.
Fecha de publicación:
42020 -
Characterization of M-stars in the LMC in the JWST eraWe study the M-type asymptotic giant branch (AGB) population of the Large Magellanic Cloud (LMC) by characterizing the individual sources in terms of the main properties of the progenitors and of the dust present in the circumstellar envelope. To this aim we compare the combination of the spectroscopic and photometric data collected by SpitzerMarini, E. et al.
Fecha de publicación:
42020 -
Stellar Characterization of M Dwarfs from the APOGEE Survey: A Calibrator Sample for M-dwarf MetallicitiesWe present spectroscopic determinations of the effective temperatures, surface gravities, and metallicities for 21 M dwarfs observed at high resolution (R ∼ 22,500) in the H band as part of the Sloan Digital Sky Survey (SDSS)-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. The atmospheric parameters and metallicities areSouto, Diogo et al.
Fecha de publicación:
22020 -
Characterizing the companion AGBs using surface chemical composition of barium starsBarium stars are one of the important probes to understand the origin and evolution of slow neutron-capture process elements in the Galaxy. These are extrinsic stars, where the observed s-process element abundances are believed to have an origin in the now invisible companions that produced these elements at their asymptotic giant branch (AGB)Shejeelammal, J. et al.
Fecha de publicación:
32020 -
Metallicity and α-Element Abundance Gradients along the Sagittarius Stream as Seen by APOGEEUsing 3D positions and kinematics of stars relative to the Sagittarius (Sgr) orbital plane and angular momentum, we identify 166 Sgr stream members observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE) that also have Gaia DR2 astrometry. This sample of 63/103 stars in the Sgr trailing/leading arm is combined with an APOGEEHayes, Christian R. et al.
Fecha de publicación:
12020 -
The Central Star of NGC 2346 as a Clue to Binary Evolution through the Common Envelope PhaseWe present an analysis of the binary central star of the planetary nebula NGC 2346 based on archival data from the International Ultraviolet Explorer, and new low- and high-resolution optical spectra (3700-7300 Å). By including in the spectral analysis the contribution of both stellar and nebular continuum, we reconciled long-time discrepant UV andGómez-Muñoz, M. A. et al.
Fecha de publicación:
112019 -
Physical parameters of red supergiants in dwarf irregular galaxies in the Local GroupContext. Increasing the statistics of evolved massive stars in the Local Group enables investigating their evolution at different metallicities. During the late stages of stellar evolution, the physics of some phenomena, such as episodic and systematic mass loss, are not well constrained. For example, the physical properties of red supergiantsBritavskiy, N. E. et al.
Fecha de publicación:
112019