Año de inicio
2010
Unidad organizativa
Institución organizadora
Subvenciones relacionadas:
General
Descripción
La espectroscopía de estrellas nos permite determinar las propiedades y composiciones químicas de las mismas. A partir de esta información para estrellas de diferente edad en la Vía Láctea es posible reconstruir la evolución química de la Galaxia, así como el origen de los elementos más pesados que el boro, forjados principalmente en los interiores estelares. También es posible estudiar la formación estelar, y la de la propia Galaxia, a través de la huella que deja el potencial Galáctico en las órbitas de las estrellas, y de las distribuciones de masa, edad y la abundancia de elementos pesados.
La obtención de espectros con alta resolución espectral, apropiados para estudios de la composición química, requiere instrumentación sofisticada y eficiente. Esto es especialmente cierto en investigaciones en las que se necesitan extensas muestras de estrellas, que exigen observar cientos, o incluso miles de fuentes de forma simultánea. El procesado y análisis de los datos debe ser automatizado para ser igualmente eficiente.
La interpretación de los espectros se basa en modelos físicos de las atmósferas de las estrellas, de donde se escapa la luz que observamos. Los ingredientes fundamentales para la construcción de estos modelos son la dinámica de fluidos, y las propiedades de los átomos, iones y moléculas, especialmente en lo que se refiere a sus interacciones con la radiación que proviene del interior estelar. Una vez que se tiene un modelo plausible, es posible calcular de forma detallada cómo se propaga la radiación a través de la atmósfera estelar, y el espectro emergente, para, de forma iterativa, compararlo con las observaciones y refinar el modelo.
Este Proyecto incluye tres diferentes frentes de investigación:
- La mejora de los modelos de atmósfera y las simulaciones de espectros estelares.
- El desarrollo de herramientas para la obtención, reducción y el análisis de observaciones espectroscópicas, y en particular para la determinación de abundancias químicas en estrellas.
- El diseño, preparación, y ejecución de estudios espectroscópicos de estrellas con el fin de entender a) los aspectos más relevantes de la física de las atmósferas estelares, b) la formación y evolución de las estrellas, c) el origen de los elementos químicos y d) la formación, estructura y evolución química de la Vía Láctea.
Miembros
Investigador principal
Carlos
Allende Prieto
Personal del proyecto
Prof.
Rafael
Rebolo López
Yeisson Fabián
Martínez Osorio
Thomas
Masseron
Colaboradores
Andrés
Asensio Ramos
Juan
Calvo Tovar
Jorge
Casares Velázquez
Martín
López Corredoira
José Alfonso
López Aguerri
Claudio
Dalla Vecchia
Domingo Aníbal
García Hernández
Ramón
García López
Fabio
Tenegi Sanginés
FRANCISCO SHU
KITAURA JOYANES
Jonay Isai
González Hernández
Olga María
Zamora Sánchez
Pablo
Rodríguez Gil
Dr.
I. Hubeny
Dr.
D.L. Lambert
Dr.
L. Koesterke
Dr.
I. Ramirez
Dr.
M. Shetrone
Dr.
J.J. Hermes
Dr.
D. E. Winget
Dr.
B. Castanheira
Dr.
M. Asplund
Dr.
W. Brown
Dr.
M. Kilic
Dr.
S. Majewski
Dr.
R. Schiavon
Dr.
J. Holtzman
Dr.
H.G. Ludwig
Dr.
T. Beers
Dr.
V. S. Smith
Dr.
Y. Sun Lee
Dr.
M. Cropper
Dr.
D. Kawata
Dr.
M. P. Ruffoni
Dr.
J. C. Pickering
Dr.
K. Cunha
Dr.
C. Rockosi
Dr.
Andrew Cooper
Dr.
Boris Gaensicke
Resultados
- Completar la instalación y pruebas de HORuS en GTC
- Descubrir dos nuevas estrellas con abundancias de hierro inferiores a 100.000 veces el valor solar
- Completar la clasificación de los espectros de APOGEE con K-means
- Publicar una colección completa de espectros modelo para estrellas O a M
- Identificar la huella de la difusión química en las atmósferas de estrellas del cúmulo M67
Actividad científica
Publicaciones relacionadas
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The Shapes of Stellar SpectraStellar atmospheres separate the hot and dense stellar interiors from the emptiness of space. Radiation escapes from the outermost layers of a star, carrying direct physical information. Underneath the atmosphere, the very high opacity keeps radiation thermalized and resembling a black body with the local temperature. In the atmosphere the opacityAllende Prieto, Carlos
Fecha de publicación:
32023 -
Survey Operations for the Dark Energy Spectroscopic InstrumentThe Dark Energy Spectroscopic Instrument (DESI) survey is a spectroscopic survey of tens of millions of galaxies at 0 < z < 3.5 covering 14,000 sq. deg. of the sky. In its first 1.1 yr of survey operations, it has observed more than 14 million galaxies and 4 million stars. We describe the processes that govern DESI's observations of the 15,000Schlafly, Edward F. et al.
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122023 -
The <SUP>12</SUP>C/<SUP>13</SUP>C isotopic ratio at the dawn of chemical evolutionContext. The known mega metal-poor (MMP) and hyper metal-poor (HMP) stars, with [Fe/H] < −6.0 and < −5.0, respectively, likely belong to the CEMP-no class, namely, carbon-enhanced stars with little or no second peak neutron-capture elements. They are likely second-generation stars, and the few elements measurable in their atmospheres are used toMolaro, P. et al.
Fecha de publicación:
112023 -
Optical and Infrared Counterparts of the X-Ray Sources Detected in the Chandra Cygnus OB2 Legacy SurveyThe young massive OB association Cygnus OB2, in the Cygnus X complex, is the closest (~1400 pc) star-forming region to the Sun hosting thousands of young low-mass stars and up to 1000 OB stars, among which are some of the most massive stars known in our Galaxy. This region holds great importance for several fields of modern astrophysics, such asGuarcello, M. G. et al.
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112023 -
The Pristine survey - XXII. A serendipitous discovery of an extremely Li-rich very metal-poor giant and a new method of <SUP>6</SUP>Li/<SUP>7</SUP>Li isotope measurementWe report the serendipitous discovery of a very metal-poor (VMP) Li-rich giant star (T eff = 4690 ± 80 K, log g = 1.34 ± 0.13, [Fe/H] = -2.43 ± 0.07). We analyse the Li I 6103 and 6707 Å lines accounting for departures from local thermodynamic equilibrium (NLTE) and correcting for 3D effects using literature data, which yields a lithium abundanceSitnova, T. M. et al.
Fecha de publicación:
122023 -
GTC Follow-up Observations of Very Metal-poor Star Candidates from DESIThe observations from the Dark Energy Spectroscopic Instrument (DESI) will significantly increase the numbers of known extremely metal-poor stars by a factor of ~10, improving the sample statistics to study the early chemical evolution of the Milky Way and the nature of the first stars. In this paper we report follow-up observations with highAllende Prieto, Carlos et al.
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112023 -
A Tale of Two Disks: Mapping the Milky Way with the Final Data Release of APOGEEWe present new maps of the Milky Way disk showing the distribution of metallicity ([Fe/H]), α-element abundances ([Mg/Fe]), and stellar age, using a sample of 66,496 red giant stars from the final data release (DR17) of the Apache Point Observatory Galactic Evolution Experiment survey. We measure radial and vertical gradients, quantify theImig, Julie et al.
Fecha de publicación:
92023 -
The Gaia-ESO Survey: Homogenisation of stellar parameters and elemental abundancesThe Gaia-ESO Survey is a public spectroscopic survey that targeted ≳10 5 stars covering all major components of the Milky Way from the end of 2011 to 2018, delivering its final public release in May 2022. Unlike other spectroscopic surveys, Gaia-ESO is the only survey that observed stars across all spectral types with dedicated, specialisedHourihane, A. et al.
Fecha de publicación:
82023 -
Decoding the compositions of four bright r-process-enhanced starsThere has been a concerted effort in recent years to identify the astrophysical sites of the r-process that can operate early in the galaxy. The discovery of many r-process-enhanced (RPE) stars (especially by the R-process Alliance collaboration) has significantly accelerated this effort. However, only limited data exist on the detailed elementalSaraf, Pallavi et al.
Fecha de publicación:
102023 -
iNNterpol: High-precision interpolation of stellar atmospheres with a deep neural network using a 1D convolutional auto encoder for feature extractionContext. Given the widespread availability of grids of models for stellar atmospheres, it is necessary to recover intermediate atmospheric models by means of accurate techniques that go beyond simple linear interpolation and capture the intricacies of the data. Aims: Our goal is to establish a reliable, precise, lightweight, and fast method forWestendorp Plaza, C. et al.
Fecha de publicación:
72023 -
Opacity for realistic 3D MHD simulations of cool stellar atmospheresContext. Realistic three-dimensional time-dependent simulations of stellar near-surface convection employ the opacity binning method for the efficient and accurate computation of the radiative energy exchange. The method provides several orders of magnitude of speedup, but its implementation includes a number of free parameters. Aims: Our aim is toPerdomo García, A. et al.
Fecha de publicación:
72023 -
Stellar Characterization and Radius Inflation of Hyades M-dwarf Stars from the APOGEE SurveyWe present a spectroscopic analysis of a sample of 48 M-dwarf stars (0.2 M ⊙ < M < 0.6 M ⊙) from the Hyades open cluster using high-resolution H-band spectra from the Sloan Digital Sky Survey/Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. Our methodology adopts spectrum synthesis with LTE MARCS model atmospheres, along withWanderley, Fábio et al.
Fecha de publicación:
72023 -
sMILES SSPs: a library of semi-empirical MILES stellar population models with variable [α/Fe] abundancesWe present a new library of semi-empirical stellar population models that are based on the empirical MILES and semi-empirical sMILES stellar libraries. The models span a large range of age and metallicity, in addition to an [α/Fe] coverage from -0.2 to +0.6 dex, at MILES resolution (FWHM = $2.5\,$ Å) and wavelength coverage ($3540.5-7409.6\,$ Å)Knowles, Adam T. et al.
Fecha de publicación:
82023 -
The Pristine Inner Galaxy Survey (PIGS) VII: a discovery of the first inner Galaxy CEMP-r/s starWell-studied very metal-poor (VMP, [Fe/H] <-2) stars in the inner Galaxy are few in number, and they are of special interest because they are expected to be among the oldest stars in the Milky Way. We present high-resolution spectroscopic follow-up of the carbon-enhanced metal-poor (CEMP) star Pristine_184237.56-260624.5 (hereafter Pr184237)Mashonkina, L. et al.
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82023 -
Overview of the DESI Milky Way SurveyWe describe the Milky Way Survey (MWS) that will be undertaken with the Dark Energy Spectroscopic Instrument (DESI) on the Mayall 4 m telescope at the Kitt Peak National Observatory. Over the next 5 yr DESI MWS will observe approximately seven million stars at Galactic latitudes |b| > 20°, with an inclusive target selection scheme focused on theCooper, Andrew P. et al.
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42023 -
DAHe white dwarfs from the DESI SurveyA new class of white dwarfs, dubbed DAHe, that present Zeeman-split Balmer lines in emission has recently emerged. However, the physical origin of these emission lines remains unclear. We present here a sample of 21 newly identified DAHe systems and determine magnetic field strengths and (for a subset) periods that span the ranges of ≃6.5-147 MGManser, Christopher J. et al.
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62023 -
The Spectroscopic Data Processing Pipeline for the Dark Energy Spectroscopic InstrumentWe describe the spectroscopic data processing pipeline of the Dark Energy Spectroscopic Instrument (DESI), which is conducting a redshift survey of about 40 million galaxies and quasars using a purpose-built instrument on the 4 m Mayall Telescope at Kitt Peak National Observatory. The main goal of DESI is to measure with unprecedented precision theGuy, J. et al.
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42023 -
DESI Observations of the Andromeda Galaxy: Revealing the Immigration History of Our Nearest NeighborWe present Dark Energy Spectroscopic Instrument (DESI) observations of the inner halo of M31, which reveal the kinematics of a recent merger-a galactic immigration event-in exquisite detail. Of the 11,416 sources studied in 3.75 hr of on-sky exposure time, 7438 are M31 sources with well-measured radial velocities. The observations reveal intricateDey, Arjun et al.
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22023 -
The Pristine survey - XX. GTC follow-up observations of extremely metal-poor stars identified from Pristine and LAMOSTUltra-metal-poor stars ($\rm {[Fe/H]} \lt -4.0$) are very rare, and finding them is a challenging task. Both narrow-band photometry and low-resolution spectroscopy have been useful tools for identifying candidates, and in this work, we combine both approaches. We cross-matched metallicity-sensitive photometry from the Pristine survey with the lowArentsen, Anke et al.
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32023 -
The pristine nature of SMSS 1605−1443 revealed by ESPRESSOContext. SMSS J160540.18−144323.1 is the carbon-enhanced metal-poor (CEMP) star with the lowest iron abundance ever measured, [Fe/H] = −6.2, which was first reported with the SkyMapper telescope. The carbon abundance is A(C)≈6.1 in the low-C band, as the majority of the stars in this metallicity range. Yet, constraining the isotopic ratio of keyAguado, D. S. et al.
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12023
Charlas relacionadas
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Proyectos relacionados
HORuS - High Optical Resolution Spectrograph
Espectrógrafo de alta resolución en operación en el Gran Telescopio Canarias (GTC) de 10m. usando componentes del espectrógrafo UES, utilizado en el Telescopio William Herschel (WHT) de 4.2 m. entre los años 1992 y 2001.
Carlos
Allende Prieto
SEVERO OCHOA 2016 - 2019
El Gobierno español concede la Acreditación como Centro de Excelencia Severo Ochoa con el fin de reconocer, premiar y promover la investigación científica de alto nivel en los centros y unidades españoles que tengan un alto nivel de excelencia en el ámbito internacional. Los objetivos específicos del Programa Severo Ochoa son: - Mejorar la
Rafael
Rebolo López
