Examinando por Autor "Negueruela, I."

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Acceso Abierto
A Catalog of Galactic Multiple Systems with a Red Supergiant and a B Star.
(The Institute of Physics (IOP), 2020-01-27) Pantaleoni González, M.; Maíz Apellániz, J.; Barbá, R. H.; Negueruela, I.
This article has no abstract
Acceso Abierto
A comprehensive study of NGC 2345, a young open cluster with a low metallicity
(EDP Sciences, 2019-11-05) Alonso Santiago, J.; Negueruela, I.; Marco, A.; Tabernero, H.; González Fernández, C.; Castro, N.; European Southern Observatory (ESO); Agencia Estatal de Investigación (AEI); Ministerio de Economía y Competitividad (MINECO); European Research Council (ERC); González Fernández, C. [0000-0003-2612-0118]; Tabernero, H. [0000-0002-8087-4298]; Castro, N. [0000-0003-0521-473X]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. NGC 2345 is a young open cluster that hosts seven blue and red supergiants, low metallicity, and a high fraction of Be stars, which makes it a privileged laboratory to study stellar evolution. Aims. We aim to improve the determination of the cluster parameters and study the Be phenomenon. Our objective is also to characterise the seven evolved stars found in NGC 2345 by deriving their atmospheric parameters and chemical abundances. Methods. We performed a complete analysis combining for the first time ubvy photometry with spectroscopy as well as the Gaia Data Release 2. We obtained spectra with classification purposes for 76 stars and high-resolution spectroscopy for an in-depth analysis of the blue and red evolved stars. Results. We identify a new red supergiant and 145 B-type likely members within a radius of 18.7 ± 1.2 arcmin, which implies an initial mass, Mcl ≈ 5200 M⊙. We find a distance of 2.5 ± 0.2 kpc for NGC 2345, placing it at RGC = 10.2 ± 0.2 kpc. Isochrone fitting supports an age of 56 ± 13 Ma, implying masses around 6.5 M⊙ for the supergiants. A high fraction of Be stars (≈10%) is found. From the spectral analysis we estimate an average vrad = +58.6 ± 0.5 km s−1 and a low metallicity, [Fe/H] = −0.28 ± 0.07, for the cluster. We also determine chemical abundances for Li, O, Na, Mg, Si, Ca, Ti, Ni, Rb, Y, and Ba for the evolved stars. The chemical composition of the cluster is consistent with that of the Galactic thin disc. One of the K supergiants, S50, is a Li-rich star, presenting an A(Li) ≈ 2.1. An overabundance of Ba is found, supporting the enhanced s-process. Conclusions. NGC 2345 has a low metallicity for its Galactocentric distance, which is comparable to typical Large Magellanic Cloud stars. It is massive enough to serve as a test bed for theoretical evolutionary models for massive intermediate-mass stars.
Acceso Abierto
Advances in Understanding High-Mass X-ray Binaries with INTEGRALand Future Directions
(Elsevier BV, 2019-12-13) Kretschmar, P.; Fürst, F.; Sidoli, L.; Bozzo, E.; Alfonso Garzón, J.; Bodaghee, A.; Chaty, S.; Chernyakova, M.; Ferrigno, C.; Manousakis, A.; Negueruela, I.; Postnov, K.; Paizis, A.; Reig, P.; Rodes Roca, J. J.; Coe, M. J.; Domingo, A.; Doroshenko, V.; Ducci, L.; Falanga, M.; Grebenev, S. A.; Grinberg, V.; Hemphill, P.; Kreykenbohm, I.; Fritz, S. K.; Li, J.; Lutovinov, A. A.; Martínez Nuñez, S.; Mas Hesse, J. M.; Masetti, N.; McBride, V. A.; Neronov, A.; Pottschmidt, K.; Rodríguez, J.; Romano, P.; Rothschild, R. E.; Santangelo, A.; Sguera, V.; Staubert, R.; Tomsick, J. A.; Torrejón, José Miguel; Torres, D. F.; Walter, R.; Wilms, J.; Wilson Hodge, C. A.; Zhang, S.; Agenzia Spaziale Italiana (ASI); Istituto Nazionale Astrofisica (INAF); Russian Foundation for Basic Research (RFBR); Agencia Estatal de Investigación (AEI); Wilms, J. [0000-0003-2065-5410]; Santangelo, A. [0000-0003-4187-9560]; Grinberg, V. [0000-0003-2538-0188]; Sguera, V. [0000-0001-8202-9381]; Martínez Núñez, S. [0000-0002-5134-4191]; Rodes Roca, J. J. [0000-0003-4363-8138]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
High mass X-ray binaries are among the brightest X-ray sources in the Milky Way, as well as in nearby Galaxies. Thanks to their highly variable emissions and complex phenomenology, they have attracted the interest of the high energy astrophysical community since the dawn of X-ray Astronomy. In more recent years, they have challenged our comprehension of physical processes in many more energy bands, ranging from the infrared to very high energies. In this review, we provide a broad but concise summary of the physical processes dominating the emission from high mass X-ray binaries across virtually the whole electromagnetic spectrum. These comprise the interaction of stellar winds with the high gravitational and magnetic fields of compact objects, the behaviour of matter under extreme magnetic and gravity conditions, and the perturbation of the massive star evolutionary processes by presence in a binary system. We highlight the role of the INTEGRAL mission in the discovery of many of the most interesting objects in the high mass X-ray binary class and its contribution in reviving the interest for these sources over the past two decades. We show how the INTEGRAL discoveries have not only contributed to significantly increase the number of high mass X-ray binaries known, thus advancing our understanding of the population as a whole, but also have opened new windows of investigation that stimulated the multi-wavelength approach nowadays common in most astrophysical research fields. We conclude the review by providing an overview of future facilities being planned from the X-ray to the very high energy domain that will hopefully help us in finding an answer to the many questions left open after more than 18 years of INTEGRAL scientific observations.
Acceso Abierto
Lucky spectroscopy, an equivalent technique to lucky imaging II. Spatially resolved intermediate-resolution blue-violet spectroscopy of 19 close massive binaries using the William Herschel Telescope
(EDP Sciences, 2021-06-29) Maíz Apellániz, J.; Barbá, R. H.; Fariña, C.; Sota, A.; Pantaleoni González, M.; Holgado, G.; Negueruela, I.; Simón Díaz, S.; European Commission (EC); Agencia Estatal de Investigación (AEI); Canary Islands Government; Agencia Canaria de Investigación, Innovación y Sociedad de la Información (ACIIS); Ministerio de Economía y Competitividad (MINECO); Maíz Apellániz, J. [0000-0003-0825-3443]; Barbá, R. H. [0000-0003-1086-1579]; Fariña, C. [0000-0003-4940-3751]; Sota, A. [0000-0002-9404-6952]; Pantaleoni González, M. [0000-0001-9933-1229]; Holgado, G. [0000-0002-9296-8259]; Negueruela, I. [0000-0003-1952-3680]; Centro de Excelencia Científica Severo Ochoa Instituto de Astrofísica de Andalucía CSIC, SEV-2015-0548
Context. Many massive stars have nearby companions. These hamper a characterization of massive stars through spectroscopy. Aims. We continue to obtain spatially resolved spectroscopy of close massive visual binaries to derive their spectral types. Methods. We used the lucky spectroscopy technique to obtain a large number of short long-slit spectroscopic exposures of 19 close visual binaries under good seeing conditions. We selected those with the best characteristics, extracted the spectra using multiple-profile fitting, and combined the results to derive spatially separated spectra. The results were analyzed in combination with data from lucky imaging, regular intermediate-resolution single-order spectroscopy, and échelle high-resolution spectroscopy. Results. The new application of lucky spectroscopy has allowed us (among other results) to [a] spatially disentangle two O stars (FN CMa B and 6 Cas B) with brighter BA supergiant companions for the first time; [b] determine that two B stars (α Sco B and HD 164 492 B) with close and more massive companions are fast rotators (in the second case, solving a case of mistaken identity); [c] extend the technique to cases with extreme magnitude differences (the previous two cases plus CS Cam A,B), shorter separations (HD 193 443 A,B), and fainter primary magnitudes down to B = 11 (HD 219 460 A,B); [d] spatially disentangle the spectra of stars with companions as diverse as an A supergiant (6 Cas A), a Wolf-Rayet star (HD 219 460 B = WR 157), and an M supergiant (α Sco A); [e] discover the unexpected identity of some targets such as two previously unknown bright O stars (HD 51 756 B and BD +60 544) and a new member of the rare OC category (HD 8768 A); and [f] identify and classify (in some cases for the first time) which of the components of four visual binaries (σ Ori, HD 219 460, HD 194 649, and HD 191 201) is a double-lined spectroscopic binary. For another seven systems (FN CMa, σ Sco, HD 51 756, HD 218 195, HD 17 520, HD 24 431, and HD 164 492), we detect signs of spectroscopic binarity using high-spectral-resolution spectroscopy. We also determine the limits of the technique.
Acceso Abierto
MONOS: Multiplicity Of Northern O-type Spectroscopic systems I. Project description and spectral classifications and visual multiplicity of previously known objects
(EDP Sciences, 2019-06-05) Maíz Apellániz, J.; Trigueros Páez, E.; Negueruela, I.; Barbá, R. H.; Simón Díaz, S.; Lorenzo, J.; Sota, A.; Gamen, R. C.; Fariña, C.; Salas, J.; Caballero, J. A.; Morrell, N. I.; Pellerín, A.; Alfaro, E. J.; Herrero, A.; Arias, J. I.; Marco, A.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Cabildo de Gran Canaria; 0000-0003-0825-3443; 0000-0001-6770-1977; 0000-0003-1952-3680; 0000-0001-5358-0932; 0000-0002-9404-6952; 0000-0002-5227-9627; 0000-0002-7349-1387; 0000-0003-1887-1966; 0000-0001-8768-2179; 0000-0002-9594-1879; Centros de Excelencia Severo Ochoa, INSTITUTO DE ASTROFÍSICA DE CANARIAS (IAC), SEV-2015-0548; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. Multiplicity in massive stars is key to understanding the chemical and dynamical evolution of galaxies. Among massive stars, those of O type play a crucial role due to their high masses and short lifetimes. Aims. MONOS (Multiplicity Of Northern O-type Spectroscopic systems) is a project designed to collect information and study O-type spectroscopic binaries with δ > −20°. In this first paper we describe the sample and provide spectral classifications and additional information for objects with previous spectroscopic and/or eclipsing binary orbits. In future papers we will test the validity of previous solutions and calculate new spectroscopic orbits. Methods. The spectra in this paper have two sources: the Galactic O-Star Spectroscopic Survey (GOSSS), a project that obtains blue-violet R ∼ 2500 spectroscopy of thousands of massive stars, and LiLiMaRlin, a library of libraries of high-resolution spectroscopy of massive stars obtained from four different surveys (CAFÉ-BEANS, OWN, IACOB, and NoMaDS) and additional data from our own observing programs and public archives. We have also used lucky images obtained with AstraLux. Results. We present homogeneous spectral classifications for 92 O-type spectroscopic multiple systems and ten optical companions, many of them original. We discuss the visual multiplicity of each system with the support of AstraLux images and additional sources. For eleven O-type objects and for six B-type objects we present their first GOSSS spectral classifications. For two known eclipsing binaries we detect double absorption lines (SB2) or a single moving line (SB1) for the first time, to which we add a third system reported by us recently. For two previous SB1 systems we detect their SB2 nature for the first time and give their first separate spectral classifications, something we have also done for a third object just recently identified as a SB2. We also detect nine new astrometric companions and provide updated information on several others. We emphasize the results for two stars: for σ Ori AaAbB we provide spectral classifications for the three components with a single observation for the first time thanks to a lucky spectroscopy observation obtained close to the Aa,Ab periastron and for θ1 Ori CaCb we add it to the class of Galactic Of?p stars, raising the number of its members to six. Our sample of O-type spectroscopic binaries contains more triple- or higher-order systems than double systems.
Acceso Abierto
Search for Galactic runaway stars using Gaia Data Release 1 and HIPPARCOS proper motions (Corrigendum)
(EDP Sciences, 2019-09-04) Maíz Apellániz, J.; Pantaleoni González, M.; Barbá, R. H.; Simón Díaz, S.; Negueruela, I.; Lennon, D. J.; Sota, A.; Trigueros Páez, E.; Maíz Apellániz, J. [0000-0003-0825-3443]; Pantaleoni González, M. [0000-0001-9933-1229]; Barbá, R. [0000-0003-1086-1579]; Simón Díaz, S. [0000-0003-1168-3524]; Trigueros Páez, E. [0000-0001-6770-1977]
Erratum for: A&A, 616, A149 (2018), https://doi.org/10.1051/0004-6361/201832787