Examinando por Autor "Nagel, E."

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Acceso Abierto
A giant exoplanet orbiting a very-low-mass star challenges planet formation models
(American Association for the Advancement of Science, 2019-09-27) Morales, J. C.; Mustill, A. J.; Ribas, I.; Davies, M. B.; Reiners, A.; Bauer, F. F.; Kossakowski, D.; Herrero, E.; Rodríguez, E.; López González, M. J.; Rodríguez López, C.; Cifuentes, C.; Mordasini, C.; Jeffers, S. V.; Rix, H. W.; Ofir, A.; Kürster, M.; Henning, T.; Emsenhuber, A.; Passegger, V. M.; Abellán, F. J.; Rodríguez Trinidad, A.; Pedraz, S.; Aceituno, J.; Seifert, W.; Fernández Martín, A.; Zechmeister, M.; De Juan, E.; Perryman, M. A. C.; Antona, R.; Alonso Floriano, F. J.; Ferro, I. M.; Johnson, E. N.; Labiche, N.; Rebolo, R.; Becerril Jarque, S.; Azzaro, M.; Fuhrmeister, B.; Lizon, J. L.; Perger, M.; Brinkmöller, M.; Berdiñas, Z. M.; Galadí Enríquez, D.; López Santiago, J.; Cortés Contreras, M.; Calvo Ortega, R.; Del Burgo, C.; Gallardo Cava, I.; Rosich, A.; Cardona Guillén, C.; Cano, J.; García Vargas, M. L.; Amado, P. J.; Casanova, V.; Carro, J.; García Piquer, A.; Kaminski, A.; Chaturvedi, P.; Gesa, L.; Abril, M.; Claret, A.; González Álvarez, E.; Ammler von Eiff, M.; Czesla, S.; Barrado, D.; Dorda, R.; González Peinado, R.; Fernández Hernández, Maite; Klüter, J.; Kim, M.; Lara, L. M.; Lampón, M.; López del Fresno, M.; Lodieu, N.; Mancini, L.; Mall, U.; Martín Fernández, P.; Mirabet, E.; Nortmann, L.; Pallé, E.; Caballero, J. A.; Huke, P.; Huber, A.; Holgado, G.; Klutsch, A.; Launhardt, R.; López Salas, F. J.; Stürmer, J.; Suárez, J. C.; Tabernero, H.; Tulloch, S. M.; Veredas, G.; Vico Linares, J. I.; Vilardell, F.; Wagner, K.; Winkler, J.; Wolthoff, V.; Sánchez López, A.; Sánchez Blanco, E.; Sadegi, S.; Labarga, F.; Marfil, E.; Casasayas Barris, N.; Bergond, G.; Martín, E. L.; Mandel, H.; Sarkis, P.; Lázaro, F. J.; Luque, R.; Burn, R.; Marvin, E. L.; Martín Ruiz, S.; Sarmiento, L. F.; González Cuesta, L.; Anglada Escudé, G.; Cárdenas, M. C.; Nelson, R. P.; Moya, A.; Schäfer, S.; Reffert, S.; Casal, E.; Pascual, J.; Nowak, G.; Schlecker, M.; Quirrenbach, A.; Kemmer, J.; Pérez Medialdea, D.; Pavlov, A.; Schmitt, J. H. M. M.; Lalitha, S.; Rabaza, O.; Pérez Calpena, A.; Schöfer, P.; Llamas, M.; Redondo, P.; Ramón Ballesta, A.; Magán Madinabeitia, H.; Rodler, F.; Sota, A.; Marín Molina, J. A.; Sabotta, S.; Stahl, O.; Martínez Rodríguez, H.; Salz, M.; Stock, S.; Naranjo, V.; Sánchez Carrasco, M. A.; Stuber, T.; Sanz Forcada, J.; Johansen, A.; Baroch, D.; Lafarga, M.; Dreizler, S.; Tal Or, L.; Schweitzer, A.; Hagen, H. J.; Guenther, E. W.; Montes, D.; Aceituno, Francisco José; Arroyo Torres, B.; Benítez, D.; Kehr, M.; Béjar, V. J. S.; Zapatero Osorio, M. R.; Yan, F.; Klahr, H.; Nagel, E.; Trifonov, T.; Guàrdia, J.; Guijarro, A.; De Guindos, E.; Hatzes, A. P.; Hauschildt, P. H.; Hedrosa, R. P.; Hermelo, I.; Hernández Arabi, R.; Hernández Otero, F.; Hintz, D.; Díez Alonso, E.; Colomé, J.; González Hernández, Carmen; Solano, Enrique; Israel Science Foundation (ISF); Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT); Swiss National Science Foundation (SNSF); Deutsches Zentrum für Luft- und Raumfahrt (DLR); Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR); European Research Council (ERC); Generalitat de Catalunya; Deutsche Forschungsgemeinschaft (DFG); Queen Mary University of London; Consejo Nacional de Ciencia y Tecnología (CONACYT); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737; Morales, J. C. [0000-0003-0061-518X]; Mustill, A. J. [0000-0002-2086-3642]; Ribas, I. [0000-0002-6689-0312]; Davies, M. B. [0000-0001-6080-1190]; Bauer, F. F. [0000-0003-1212-5225]; Herrrero, E. [0000-0001-8602-6639]; Rodríguez, E. [0000-0001-6827-9077]; López González, M. J. [0000-0001-8104-5128]; Rodríguez López, C. [0000-0001-5559-7850]; López González, M. J. [0000-0001-8104-5128]; Rodríguez López, C. [0000-0001-5559-7850]; Luque, R. [0000-0002-4671-2957]; López Santiago, J. [0000-0003-2402-8166]; Perger, M. [0000-0001-7098-0372]; Guenther, E. W. [0000-0002-9130-6747]; Schmitt, J. H. M. M. [0000-0003-2554-9916]; Mordasini, C. [0000-0002-1013-2811]; Aceituno, J. [0000-0003-0487-1105]; Stock, S. [0000-0002-1166-9338]; Lafarga, M. [0000-0002-8815-9416]; Nagel, E. [0000-0002-4019-3631]; Barrado, D. [0000-0002-5971-9242]; Tulloch, S. [0000-0003-0840-8521]; Rosich, A. [0000-0002-9141-3067]; Trifonov, T. [0000-0002-0236-775X]; Bergond, G. [0000-0003-3132-9215]; Zapatero Osorio, M. R. [0000-0001-5664-2852]; Kaminski, A. [0000-0003-0203-8208]; Montes, D. [0000-0002-7779-238X]; Cano, J. [0000-0003-1984-5401]; Baroch, D. [0000-0001-7568-5161]; Alonso Floriano, F. J. [0000-0003-1202-5734]; Sabotta, S. [0000-0001-9078-5574]; Ammler-von Eiff, M. [0000-0001-9565-1698]; Chaturvedi, P. [0000-0002-1887-1192]; Anglada Escudé, G. [0000-0002-3645-5977]; Becerril Jarque, S. [0000-0001-9009-1150]; Díez Alonso, E. [0000-0002-5826-9892]; Passegger, V. M. [0000-0002-8569-7243]; Burn, R. [0000-0002-9020-7309]; García Vargas, M. L. [0000-0002-2058-3528]; Amado, P. J. [0000-0002-8388-6040]; Cardona Guillén, C. [0000-0002-2198-4200]; Carro, J. [0000-0002-0838-3603]; Guàrdia, J. [0000-0002-7191-9001]; Abellán, F. J. [0000-0002-5724-1636]; Cifuentes, C. [0000-0003-1715-5087]; Colomé, J. [0000-0002-1678-2241]; Hermelo, I. [0000-0001-9178-694X]; Arroyo Torres, B. [0000-0002-3392-4694]; Emsenhuber, A. [0000-0002-8811-1914]; Fuhrmeister, B. [0000-0001-8321-5514]; Johnson, E. [0000-0003-2260-5134]; Berdiñas, Z. M. [0000-0002-6057-6461]; González Álvarez, E. [0000-0002-4820-2053]; González Cuesta, L. [0000-0002-1241-5508]; González Hernández, J. I. [0000-0002-0264-7356]; Klüter, J. [0000-0002-3469-5133]; Calvo Ortega, R. [0000-0003-3693-6030]; Guijarro, A. [0000-0001-5518-1759]; Lara, L. M. [0000-0002-7184-920X]; Casasayas Barris, N. [0000-0002-2891-8222]; Hintz, D. [0000-0002-5274-2589]; López del Fresno, M. [0000-0002-9479-7780]; Czesla, S. [0000-0002-4203-4773]; De Juan Fernández, E. [0000-0002-9382-4505]; Kehr, M. [0000-0002-7420-7368]; Marín Molina, J. A. [0000-0002-3525-0806]; Galadí Enríquez, D. [0000-0003-4946-5653]; Klutsch, A. [0000-0001-7869-3888]; Labarga, F. [0000-0002-7143-0206]; Martínez Rodríguez, H. [0000-0002-1919-228X]; González Peinado, R. [0000-0002-6658-8930]; Launhardt, R. [0000-0002-8298-2663]; Lizon, J. L. [0000-0001-8928-2566]; Naranjo, V. [0000-0003-0097-1061]; De Guindos, E. [0000-0002-8124-9101]; Magan Madinabeitia, H. [0000-0003-1243-4597]; Aceituno, F. J. [0000-0001-8074-4760]; Manici, L. [0000-0002-9428-8732]; Ofir, A. [0000-0002-9152-5042]; Huke, P. [0000-0001-5913-2743]; Martín, E. [0000-0002-1208-4833]; Rabaza, O. [0000-0003-2766-2103]; Kim, M. [0000-0001-6218-2004]; Marvin, C. J. [0000-0002-2249-2611]; Rodríguez Trinidad, A. [0000-0002-3356-8634]; Lampón, M. [0000-0002-0183-7158]; Nelson, R. [0000-0002-9687-8779]; Nortmann, L. [0000-0001-8419-8760]; Sanz Forcada, J. [0000-0002-1600-7835]; Lodieu, N. [0000-0002-3612-8968]; Pascual Granado, J. [0000-0003-0139-6951]; Pedraz, S. [0000-0003-1346-208X]; Schäfer, S. [0000-0001-8597-8048]; Marfil, E. [0000-0001-8907-4775]; Ramón Ballesta, A. [0000-0002-4323-0610]; Redondo, P. G. [0000-0001-5992-5778]; Schöfer, P. [0000-0002-5969-3708]; Martín Ruiz, S. [0000-0002-9006-7182]; Sadegi, S. [0000-0001-9897-6121]; García Piquer, A. [0000-0002-6872-4262]; Sánchez Carrasco, M. A. [0000-0001-5533-3660]; Stuber, T. [0000-0003-2185-0525]; Moya, A. [0000-0003-1665-5389]; Sarkis, P. [0000-0001-8128-3126]; Vilardell, F. [0000-0003-0441-1504]; Nowak, G. [0000-0002-7031-7754]; Schlecker, M. [0000-0001-8355-2107]; Béjar, V. J. S. [0000-0002-5086-4232]; Pérez Calpena, A. [0000-0001-7361-9240]; Solano, E. [0000-0003-1885-5130]; Sota, A. [https://orcid.org/0000-0002-9404-6952]; Klahr, H. [0000-0002-8227-5467]; Rodler, F. [0000-0003-0650-5723]; Suárez, J. C. [0000-0003-3649-8384]; Tabernero, H. [0000-0002-8087-4298]; Cortés Contreras, M. [0000-0003-3734-9866]; Sánchez López, A. [0000-0002-0516-7956]; Winkler, J. [0000-0003-0568-8820]; Yan, F. [0000-0001-9585-9034]; Reffert, S. [0000-0002-0460-8289]; Sarmiento, L. F. [0000-0002-8475-9705]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFISICA DE ANDALUCIA (IAA), SEV-2017-0709
Surveys have shown that super-Earth and Neptune-mass exoplanets are more frequent than gas giants around low-mass stars, as predicted by the core accretion theory of planet formation. We report the discovery of a giant planet around the very-low-mass star GJ 3512, as determined by optical and near-infrared radial-velocity observations. The planet has a minimum mass of 0.46 Jupiter masses, very high for such a small host star, and an eccentric 204-day orbit. Dynamical models show that the high eccentricity is most likely due to planet-planet interactions. We use simulations to demonstrate that the GJ 3512 planetary system challenges generally accepted formation theories, and that it puts constraints on the planet accretion and migration rates. Disk instabilities may be more efficient in forming planets than previously thought.Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science
Acceso Abierto
Stellar atmospheric parameters of FGK-type stars from high-resolution optical and near-infrared CARMENES spectra
(Oxford Academics: Oxford University Press, 2020-01-10) Marfil, E.; Tabernero, H. M.; Montes, D.; Caballero, J. A.; Soto, M. G.; Kaminski, A.; Nagel, E.; Jeffers, S. V.; Reiners, A.; Ribas, I.; Quirrenbach, A.; Amado, P. J.; González Hernández, Carmen; Fundacao para a Ciencia e a Tecnologia (FCT); Deutsche Forschungsgemeinschaft (DFG); Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); 0000-0001-8907-4775; 0000-0002-8087-4298; 0000-0002-7349-1387; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
With the purpose of assessing classic spectroscopic methods on high-resolution and high signal-to-noise ratio spectra in the near-infrared wavelength region, we selected a sample of 65 F-, G-, and K-type stars observed with CARMENES, the new, ultra-stable, double channel spectrograph at the 3.5 m Calar Alto telescope. We computed their stellar atmospheric parameters (Teti, log g, 4, and [Fell I]) by means of the STEPAR code, a PYTHON implementation of the equivalent width method that employs the 2017 version of the MOOG code and a grid of MARCS model atmospheres. We compiled four Fe 1 and Fe tl line lists suited to metal-rich dwarfs, metal-poor dwarfs, metal-rich giants, and metal-poor giants that cover the wavelength range from 5300 to 17 100 A, thus substantially increasing the number of identified Fe! and Felt lines up to 653 and 23, respectively, We examined the impact of the near-infrared Fe and Fen lines upon our parameter determinations after an exhaustive literature search, placing special emphasis on the 14 Gala benchmark stars contained in our sample, Even though our parameter determinations remain in good agreement with the literature values, the increase in the number of Fel and Feu lines when the near-infrared region is taken into account reveals a deeper Teff scale that might stem from a higher sensitivity of the near-infrared lines to Tff.C 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
Acceso Abierto
The CARMENES search for exoplanets around M dwarfs A deep learning approach to determine fundamental parameters of target stars
(EDP Sciences, 2020-09-30) Passegger, V. M.; Bello García, A.; Ordieres Meré, J.; Caballero, J. A.; Schweitzer, A.; González Marcos, A.; Ribas, I.; Reiners, A.; Quirrenbach, A.; Amado, P. J.; Azzaro, M.; Bauer, F. F.; Béjar, V. J. S.; Cortés Contreras, M.; Dreizler, S.; Hatzes, A. P.; Henning, T.; Jeffers, S. V.; Kaminski, A.; Kürster, M.; Lafarga, M.; Marfil, E.; Montes, D.; Morales, J. C.; Nagel, E.; Sarro, L. M.; Tabernero, H. M.; Zechmeister, M.; Solano, Enrique; Agencia Estatal de Investigación (AEI); Fundacao para a Ciencia e a Tecnologia (FCT); National Aeronautics and Space Administration (NASA); Bello García, A. [0000-0001-8691-3342]; Ordieres Meré, J. [0000-0002-9677-6764]; Caballero, J. A. [0000-0002-7349-1387]; González Marcos, A. [0000-0003-4684-659X]; Ribas, I. [0000-0002-6689-0312]; Azzaro, M. [0000-0002-1317-0661]; Kürster, M. [0000-0002-1765-9907]; Marfil, E. [0000-0001-8907-4775]; Montes, D. [0000-0002-7779-238X]; Morales, J. C. [0000-0003-0061-518X]; Nagel, E. [0000-0002-4019-3631]; Sarro, L. M. [0000-0002-5622-5191]; Tabernero, H. [0000-0002-8087-4298]; Zechmesister, M. [0000-0002-6532-4378]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Existing and upcoming instrumentation is collecting large amounts of astrophysical data, which require efficient and fast analysis techniques. We present a deep neural network architecture to analyze high-resolution stellar spectra and predict stellar parameters such as effective temperature, surface gravity, metallicity, and rotational velocity. With this study, we firstly demonstrate the capability of deep neural networks to precisely recover stellar parameters from a synthetic training set. Secondly, we analyze the application of this method to observed spectra and the impact of the synthetic gap (i.e., the difference between observed and synthetic spectra) on the estimation of stellar parameters, their errors, and their precision. Our convolutional network is trained on synthetic PHOENIX-ACES spectra in different optical and near-infrared wavelength regions. For each of the four stellar parameters, Teff, log g, [M/H], and v sin i, we constructed a neural network model to estimate each parameter independently. We then applied this method to 50 M dwarfs with high-resolution spectra taken with CARMENES (Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Échelle Spectrographs), which operates in the visible (520–960 nm) and near-infrared wavelength range (960–1710 nm) simultaneously. Our results are compared with literature values for these stars. They show mostly good agreement within the errors, but also exhibit large deviations in some cases, especially for [M/H], pointing out the importance of a better understanding of the synthetic gap.