Start year
2010
Organizational Unit
Organizing institutions
Grants related:
General
Description
Stellar spectroscopy allows us to determine the properties and chemical compositions of stars. From this information for stars of different ages in the Milky Way, it is possible to reconstruct the chemical evolution of the Galaxy, as well as the origin of the elements heavier than boron, created mainly in stellar interiors. It is also possible to study stellar formation, and the formation of the Galaxy, from the signature of the Galactic potential on the stellar orbits, and the distributions of mass, ages, and the abundance of heavy elements.
Obtaining high-resolution spectra, as necessary for studies of chemical compositions, requires advanced and efficient instrumentation. This is particularly true for research that calls for large stellar samples, which demands the observation of hundreds or thousands of sources simultaneously. Efficiency requires that the data processing and analysis are performed in an automated way.
The interpretation of spectra is based on physical models of the atmospheres of the stars, from where the light that we observe escapes the stars. The main ingredients for building such models are the fluid dynamics, and the properties of the atoms, ions, and molecules, especially regarding their interactions with the radiation coming from the stellar interior.
Once we have a plausible model, it is possible to compute in detail how the radiation propagates through the stellar atmosphere, and the emergent spectrum, which can then be iteratively compared with the observations to refine the model.
This project covers three different research fronts:
- Improving model atmospheres and simulations of stellar spectra.
- Developing tools for acquisition, reduction, and analysis of spectroscopic observations, in particular for the determination of chemical abundances in stars.
- Designing, preparing, and executing spectroscopic studies of stars aimed at understanding a) the most relevant aspects of the physics of stellar atmospheres, b) the formation and evolution of stars, c) the origin of the chemical elements, and d) the formation, structure, and evolution of the Milky Way galaxy.
Members
Principal investigator
Carlos
Allende Prieto
Project staff
Prof.
Rafael
Rebolo López
Yeisson Fabián
Martínez Osorio
Thomas
Masseron
Collaborators
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
Results
- Complete the installation and commissioning of HORuS on GTC
- Discover two new stars with more than 100,000 times less iron than the Sun
- Complete the classification of all the APOGEE spectra with K-means
- Publish a complete collection of model stellar spectra for stars O to M
- Identify the signature of chemical diffusion in the atmospheres of the stars in the cluster M67
Scientific activity
Related publications
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Sodium and Oxygen Abundances in the Open Cluster NGC 6791 from APOGEE H-band SpectroscopyThe open cluster NGC 6791 is among the oldest, most massive, and metal-rich open clusters in the Galaxy. High-resolution H-band spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) of 11 red giants in NGC 6791 are analyzed for their chemical abundances of iron, oxygen, and sodium. The abundances of these three elementsCunha, K. et al.
Advertised on:
12015 -
Low-resolution optical spectra of ultracool dwarfs with OSIRIS/GTCWe present the results of low-resolution optical spectroscopy with OSIRIS/GTC (Optical System for Imaging and Low Resolution Integrated Spectroscopy/Gran Telescopio Canarias) for a sample of ultracool dwarfs. For a subsample of seven objects, based on 2 Micron Sky Survey (2MASS) NIR photometric colours, a `photometric' spectral type is determinedMetodieva, Y. et al.
Advertised on:
22015 -
The APOKASC Catalog: An Asteroseismic and Spectroscopic Joint Survey of Targets in the Kepler FieldsWe present the first APOKASC catalog of spectroscopic and asteroseismic properties of 1916 red giants observed in the Kepler fields. The spectroscopic parameters provided from the Apache Point Observatory Galactic Evolution Experiment project are complemented with asteroseismic surface gravities, masses, radii, and mean densities determined byPinsonneault, M. H. et al.
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122014 -
The Gaia-ESO Survey: the chemical structure of the Galactic discs from the first internal data releaseAims: Until recently, most high-resolution spectroscopic studies of the Galactic thin and thick discs were mostly confined to objects in the solar vicinity. Here we aim at enlarging the volume in which individual chemical abundances are used to characterise the thin and thick discs, using the first internal data release of the Gaia-ESO survey (GESMikolaitis, Š. et al.
Advertised on:
122014 -
Disk Survival in the Extremely Massive Association Cygnus OB2Star formation in massive clusters proceeds under the influence of the intense ionizing flux emitted by OB stars. Among the massive star forming regions in our Galaxy, Cygnus OB2 is the best available target to study these processes given its relative proximity and large content of OB and low-mass stars. We present our preliminary results on theGuarcello, M. G. et al.
Advertised on:
2014 -
Tracing Chemical Evolution over the Extent of the Milky Way's Disk with APOGEE Red Clump StarsWe employ the first two years of data from the near-infrared, high-resolution SDSS-III/APOGEE spectroscopic survey to investigate the distribution of metallicity and α-element abundances of stars over a large part of the Milky Way disk. Using a sample of ≈10, 000 kinematically unbiased red-clump stars with ~5% distance accuracy as tracers, the [αNidever, D. L. et al.
Advertised on:
112014 -
The Gaia-ESO Survey: the most metal-poor stars in the Galactic bulgeWe present the first results of the EMBLA survey (Extremely Metal-poor BuLge stars with AAOmega), aimed at finding metal-poor stars in the Milky Way bulge, where the oldest stars should now preferentially reside. EMBLA utilizes SkyMapper photometry to pre-select metal-poor candidates, which are subsequently confirmed using AAOmega spectroscopy. WeAsplund, M. et al.
Advertised on:
122014 -
The Gaia-ESO Survey: The analysis of high-resolution UVES spectra of FGK-type starsContext. The ongoing Gaia-ESO Public Spectroscopic Survey is using FLAMES at the VLT to obtain high-quality medium-resolution Giraffe spectra for about 105 stars and high-resolution UVES spectra for about 5000 stars. With UVES, the Survey has already observed 1447 FGK-type stars. Aims: These UVES spectra are analyzed in parallel by several state-ofSmiljanic, R. et al.
Advertised on:
102014 -
Bayesian distances and extinctions for giants observed by Kepler and APOGEEWe present a first determination of distances and extinctions for individual stars in the first release of the APOKASC catalogue, built from the joint efforts of the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and the Kepler Asteroseismic Science Consortium (KASC). Our method takes into account the spectroscopic constraintsRodrigues, T. S. et al.
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122014 -
Accretion and Outflow in the Proplyd-like Objects Near Cygnus OB2Cygnus OB2 is the most massive association within 2 kpc from the Sun, hosting hundreds of massive stars, thousands of young low mass members, and some sights of active star formation in the surrounding cloud. Recently, 10 photoevaporating proplyd-like objects with tadpole-shaped morphology were discovered in the outskirts of the OB associationGuarcello, M. G. et al.
Advertised on:
92014 -
A new gravitational wave verification sourceWe report the discovery of a detached 20-min orbital period binary white dwarf (WD). WD 0931+444 (SDSS J093506.93+441106.9) was previously classified as a WD + M dwarf system based on its optical spectrum. Our time-resolved optical spectroscopy observations obtained at the 8 m Gemini and 6.5 m MMT reveal peak-to-peak radial velocity variations ofKilic, M. et al.
Advertised on:
102014 -
Deep SDSS optical spectroscopy of distant halo stars. I. Atmospheric parameters and stellar metallicity distributionAims: We analyze a sample of tens of thousands of spectra of halo turnoff stars, obtained with the optical spectrographs of the Sloan Digital Sky Survey (SDSS), to characterize the stellar halo population "in situ" out to a distance of a few tens of kpc from the Sun. In this paper we describe the derivation of atmospheric parameters. We also deriveAllende Prieto, C. et al.
Advertised on:
82014 -
The APOGEE Red-clump Catalog: Precise Distances, Velocities, and High-resolution Elemental Abundances over a Large Area of the Milky Way's DiskThe Sloan Digital Sky Survey III's Apache Point Observatory Galactic Evolution Experiment (APOGEE) is a high-resolution near-infrared spectroscopic survey covering all of the major components of the Galaxy, including the dust-obscured regions of the inner Milky Way disk and bulge. Here we present a sample of 10,341 likely red-clump stars (RC) fromBovy, J. et al.
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82014 -
Ultra-short Period Binaries from the Catalina SurveysWe investigate the properties of 367 ultra-short period binary candidates selected from 31,000 sources recently identified from Catalina Surveys data. Based on light curve morphology, along with WISE, Sloan Digital Sky Survey, and GALEX multi-color photometry, we identify two distinct groups of binaries with periods below the 0.22 day contactDrake, A. J. et al.
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82014 -
The Vertical Metallicity Gradient of the Milky Way Disk: Transitions in [α/Fe] PopulationsUsing G dwarfs from the Sloan Extension for Galactic Understanding and Exploration (SEGUE) survey, we have determined the vertical metallicity gradient in the Milky Way's disk and examined how this gradient varies for different [α/Fe] subsamples. Our sample contains over 40,000 stars with low-resolution spectroscopy over 144 lines of sight. It alsoSchlesinger, K. J. et al.
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82014 -
IPHAS and the symbiotic stars. III. New discoveries and their IR spectral energy distributionsContext. The IPHAS Hα survey provides a rich database to search for emission-line sources in the northern Galactic plane. Aims: We are systematically searching for symbiotic stars in the Milky Way using IPHAS. Our final goal, a complete census of this class of objects in the Galaxy, is a fundamental figure for discussing their overall propertiesRodríguez-Flores, E. R. et al.
Advertised on:
72014 -
The Gaia-ESO Survey: the Galactic thick to thin disc transitionAims: The nature of the thick disc and its relation to the thin disc is presently an important subject of debate. In fact, the structural and chemo-dynamical transition between disc populations can be used as a test of the proposed models of Galactic disc formation and evolution. Methods: We used the atmospheric parameters, [α/Fe] abundances, andRecio-Blanco, A. et al.
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72014 -
The Catalina Surveys Periodic Variable Star CatalogWe present ~47,000 periodic variables found during the analysis of 5.4 million variable star candidates within a 20,000 deg2 region covered by the Catalina Surveys Data Release-1 (CSDR1). Combining these variables with type ab RR Lyrae from our previous work, we produce an online catalog containing periods, amplitudes, and classifications for ~61Drake, A. J. et al.
Advertised on:
72014 -
Extinction Maps toward the Milky Way Bulge: Two-dimensional and Three-dimensional Tests with APOGEEGalactic interstellar extinction maps are powerful and necessary tools for Milky Way structure and stellar population analyses, particularly toward the heavily reddened bulge and in the midplane. However, due to the difficulty of obtaining reliable extinction measures and distances for a large number of stars that are independent of these mapsSchultheis, M. et al.
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72014 -
The planetary nebula IPHASXJ211420.0+434136 (Ou5): insights into common-envelope dynamical and chemical evolutionWhile analysing the images of the IPHAS (INT/WFC Photometric Hα Survey of the northern Galactic plane) survey, we noticed that the central star of the candidate planetary nebula IPHASXJ211420.0+434136 (also named Ou5) was clearly variable. This is generally considered as an indication of binarity. To confirm it, we performed a photometricCorradi, R. L. M. et al.
Advertised on:
72014
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SEVERO OCHOA 2016 - 2019
The IAC is an internationalized Spanish research centre aiming to achieve major advances in the understanding of the laws that govern the origin and evolution of the various forms of matter/energy in the Universe. Outstanding results are expected in key areas of research such as Solar physics, Sun-Earth connections, Exoplanetary systems, Solar
Rafael
Rebolo López
