Start year
1986
Organizational Unit
Organizing institutions
Grants related:
General
Description
Low- to intermediate-mass (M < 8 solar masses, Ms) stars represent the majority of stars in the Cosmos. They finish their lives on the Asymptotic Giant Branch (AGB) - just before they form planetary nebulae (PNe) - where they experience complex nucleosynthetic and molecular processes. AGB stars are important contributors to the enrichment of the interstellar medium where new stars/planets are born (including our own Early Solar System, ESS), and to the chemical evolution of stellar systems like globular clusters (GCs) and galaxies. In particular, the more massive (M > 4-5 Ms) AGB stars synthesize very different (radio)isotopes from those formed by lower mass AGB stars and Supernova detonations, as a consequence of different nucleosynthesis mechanisms. Evolved stars in the transition phase between AGB stars and PNe also form diverse organic compounds like PAHs, and fullerene and graphene molecular nanostructures, being a wonderful laboratory for Astrochemistry. On-going massive surveys like SDSS-IV/APOGEE-2 and the upcoming James Webb Space Telescope (JWST) represent a fundamental step forward to understand the nucleosynthesis and molecular processes in evolved stars. We aim to explore the nucleosynthesis of light and heavy (radio)isotopes in AGB stars and how they contribute to the ESS radioactive inventory as well as to the formation and evolution of GCs and galaxies. We also aim at understanding the top-down formation process of fullerene and graphene molecular nanostructures in evolved stars. Finally, it is intended to perform data mining with the Gaia satellite, in order to study the AGB- PNe evolutionary phase. In addition we aim to use the GALEX database to discover binary central stars in Galactic PNe.
Members
Principal investigator
Domingo Aníbal
García Hernández
Project staff
Arturo
Manchado Torres
Thomas
Masseron
Olga María
Zamora Sánchez
LUCIO
CRIVELLARI
Collaborators
Dr.
P. García Lario
Dr.
G. García Segura
Dr.
L. Stanghellini
Dr.
E. Villaver
Carlos
Allende Prieto
Jorge
García Rojas
Dr.
B. Plez
Dr.
A. Karakas
Dr.
M. Lugaro
Dr.
D. Lambert
Dr.
P. Ventura
Dr.
F. Cataldo
Dr.
Andres Yague
Dr.
Sun Kwok
Dr.
R. Szczerba
Dr.
J.M. Trigo Rodríguez
Dr.
K. Rao
S. Sadjadi
M. Manteiga
C. Dafonte
R. Santoveña
L. Bianchi
Sz. Mészáros
S. Cristallo
L. Piersanti
Results
1. During 2020, we have published 37 papers in high-impact international refereed astronomical journals (including one invited review) and 2 papers in the Chemistry -Physics journal FNCN.
2. Phosphorus-rich stars with an extremely peculiar chemical abundance pattern have been discovered for the first time, challenging the theoretical nucleosynthesis predictions.
3. It was demonstrated that the P-rich star progenitors represent a new site for s-process nucleosynthesis, with important implications for the chemical evolution of our Galaxy.
Scientific activity
Related publications
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APOGEE chemical abundances of globular cluster giants in the inner GalaxyWe report chemical abundances obtained by Sloan Digital Sky Survey (SDSS)-III/Apache Point Observatory Galactic Evolution Experiment for giant stars in five globular clusters located within 2.2 kpc of the Galactic Centre. We detect the presence of multiple stellar populations in four of those clusters (NGC 6553, NGC 6528, Terzan 5 and Palomar 6)Schiavon, R. P. et al.
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42017 -
Galactic archaeology with asteroseismology and spectroscopy: Red giants observed by CoRoT and APOGEEWith the advent of the space missions CoRoT and Kepler, it has recently become feasible to determine precise asteroseismic masses and relative ages for large samples of red giant stars. We present the CoRoGEE dataset, obtained from CoRoT light curves for 606 red giants in two fields of the Galactic disc that have been co-observed by the ApacheAnders, F. et al.
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12017 -
Clear Evidence for the Presence of Second-generation Asymptotic Giant Branch Stars in Metal-poor Galactic Globular ClustersGalactic globular clusters (GCs) are known to host multiple stellar populations: a first generation (FG) with a chemical pattern typical of halo field stars and a second generation (SG) enriched in Na and Al and depleted in O and Mg. Both stellar generations are found at different evolutionary stages (e.g., the main-sequence turnoff, the subgiantGarcía-Hernández, D. A. et al.
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122015 -
Evidence for a metal-poor population in the inner Galactic bulgeThe inner Galactic bulge has, until recently, been avoided in chemical evolution studies because of extreme extinction and stellar crowding. Large, near-IR spectroscopic surveys, such as the Apache Point Observatory Galactic Evolution Experiment (APOGEE), for the first time allow the measurement of metallicities in the inner region of our GalaxySchultheis, M. et al.
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122015 -
The SDSS-III APOGEE Spectral Line List for H-band SpectroscopyWe present the H-band spectral line lists adopted by the Apache Point Observatory Galactic Evolution Experiment (APOGEE). The APOGEE line lists comprise astrophysical, theoretical, and laboratory sources from the literature, as well as newly evaluated astrophysical oscillator strengths and damping parameters. We discuss the construction of theShetrone, M. et al.
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122015 -
AGB stars in the SMC: evolution and dust properties based on Spitzer observationsWe study the population of asymptotic giant branch (AGB) stars in the Small Magellanic Cloud (SMC) by means of full evolutionary models of stars of mass 1 M⊙ ≤ M ≤ 8 M⊙, evolved through the thermally pulsing phase. The models also account for dust production in the circumstellar envelope. We compare Spitzer infrared colours with results fromDell'Agli, F. et al.
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122015 -
An Infrared Diffuse Circumstellar Band? The Unusual 1.5272 Micron DIB In the Red Square NebulaThe molecular carriers of the ubiquitous absorption features called the diffuse interstellar bands (DIBs) have eluded identification for many decades, in part because of the enormous parameter space spanned by the candidates and the limited set of empirical constraints afforded by observations in the diffuse interstellar medium. Detection of theseZasowski, G. et al.
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102015 -
Abundances, Stellar Parameters, and Spectra from the SDSS-III/APOGEE SurveyThe SDSS-III/Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey operated from 2011–2014 using the APOGEE spectrograph, which collects high-resolution (R ∼ 22,500), near-IR (1.51–1.70 μm) spectra with a multiplexing (300 fiber-fed objects) capability. We describe the survey data products that are publicly available, which includeHoltzman, J. A. et al.
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112015 -
The Eleventh and Twelfth Data Releases of the Sloan Digital Sky Survey: Final Data from SDSS-IIIThe third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution spectrograph, and a novel optical interferometer. All of the data from SDSS-III are now made public. InAlam, S. et al.
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72015 -
High-resolution Imaging of NGC 2346 with GSAOI/GeMS: Disentangling the Planetary Nebula Molecular Structure to Understand Its Origin and EvolutionWe present high spatial resolution (≈ 60–90 mas) images of the molecular hydrogen emission in the planetary nebula (PN) NGC 2346. The data were acquired during the system verification of the Gemini Multi-conjugate Adaptive Optics System + Gemini South Adaptive Optics Imager. At the distance of NGC 2346, 700 pc, the physical resolution correspondsManchado, A. et al.
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82015 -
Chemical Cartography with APOGEE: Metallicity Distribution Functions and the Chemical Structure of the Milky Way DiskUsing a sample of 69,919 red giants from the SDSS-III/APOGEE Data Release 12, we measure the distribution of stars in the [α/Fe] versus [Fe/H] plane and the metallicity distribution functions (MDFs) across an unprecedented volume of the Milky Way disk, with radius 3 R 15 kpc and height | z| \lt 2 kpc. Stars in the inner disk (R 5 kpc) lie alongHayden, M. R. et al.
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82015 -
The radial abundance gradient of chlorine in the Milky WayWe determine the radial abundance gradient of Cl in the Milky Way from H II regions spectra. For the first time, the Cl/H ratios are computed by simply adding ionic abundances and not using an ionization correction factor (ICF). We use a collection of published very deep spectra of Galactic H II regions. We have recalculated the physical conditionsEsteban, C. et al.
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92015 -
A test for asymptotic giant branch evolution theories: planetary nebulae in the Large Magellanic CloudWe used a new generation of asymptotic giant branch (AGB) stellar models that include dust formation in the stellar winds to find the links between evolutionary models and the observed properties of a homogeneous sample of Large Magellanic Cloud (LMC) planetary nebulae (PNe). Comparison between the evolutionary yields of elements such as CNO andVentura, P. et al.
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102015 -
Constraint on the time variation of the fine-structure constant with the SDSS-III/BOSS DR12 quasar sampleFrom the Sloan Digital Sky Survey (SDSS) Data Release 12, which covers the full Baryonic Oscillation Spectroscopic Survey (BOSS) footprint, we investigate the possible variation of the fine-structure constant over cosmological time-scales. We analyse the largest quasar sample considered so far in the literature, which contains 13 175 spectra (10Albareti, F. D. et al.
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102015 -
Rapid Rotation of Low-mass Red Giants Using APOKASC: A Measure of Interaction Rates on the Post-main-sequenceWe investigate the occurrence rate of rapidly rotating (v{sin}i >10 km s‑1), low-mass giant stars in the Apache Point Observatory Galaxy Evolution Experiment-Kepler (APOKASC) fields with asteroseismic mass and surface gravity measurements. Such stars are likely merger products and their frequency places interesting constraints on stellar populationStello, D. et al.
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72015 -
Young α-enriched giant stars in the solar neighbourhoodWe derive age constraints for 1639 red giants in the APOKASC sample for which seismic parameters from Kepler, as well as effective temperatures, metallicities and [α/Fe] values from APOGEE DR12 (Apache Point Observatory Galactic Evolution Experiment Data Release 12) are available. We investigate the relation between age and chemical abundances forMartig, M. et al.
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82015 -
On the C60 Fullerene Adduct with Pentacene: Synthesis and StabilityC60 fullerene and pentacene were reacted under mild conditions in toluene, yielding the monoadduct, which was characterized by electronic absorption and Fourier transform infrared (FT-IR) spectroscopy. The C60/pentacene adduct was studied by thermogravimetric analysis and its experimental composition was found in line with the theory for a 1:1Cataldo, F. et al.
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92015 -
Chemical Thermodynamics Applied to the Diels–AlderReaction of C60 Fullerene with PolyacenesThe Diels–Alder addition reactions of a series of acenes (anthracene, 9,10-dimenthylanthracene, tetracene and pentacene) to C60 fullerene are next to equilibrium reactions and were analyzed using a classic chemical thermodynamics approach using group increment calculations. In the case of the C60/anthracene adducts and C60/dimethylanthraceneCataldo F. et al.
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92015 -
New H-band Stellar Spectral Libraries for the SDSS-III/APOGEE SurveyThe Sloan Digital Sky Survey-III (SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) has obtained high-resolution (R ∼ 22,500), high signal-to-noise ratio (\gt 100) spectra in the H-band (∼1.5–1.7 μm) for about 146,000 stars in the Milky Way galaxy. We have computed spectral libraries with effective temperature ({{T}eff})Zamora, O. et al.
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62015 -
The Large Magellanic Cloud as a laboratory for hot bottom burning in massive asymptotic giant branch starsWe use Spitzer observations of the rich population of asymptotic giant branch (AGB) stars in the Large Magellanic Cloud (LMC) to test models describing the internal structure and nucleosynthesis of the most massive of these stars, i.e. those with initial mass above ˜4 M⊙. To this aim, we compare Spitzer observations of LMC stars with theVentura, P. et al.
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72015
