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La Metalicidad De Las Enanas M

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La Metalicidad De Las Enanas M M´asterUniversitario en Astrof´ısica Universidad Complutense de Madrid Trabajo de Fin de M´aster Preparaci´ony explotaci´oncient´ıficade CARMENES: la metalicidad de las enanas M Alumno: Rodrigo Gonzalez´ Peinado I Directores: David Montes II (UCM), Jos´eAntonio Caballero III (LSW) Tutor: David Montes II (UCM) Septiembre 2016 [email protected] [email protected] [email protected] Resumen: Contexto: CARMENES es un espectr´ografode alta resoluci´oncon el que el consorcio hispano-alem´andel mismo nombre busca exotierras alrededor de unas 300 estrellas enanas de tipo espectral M por el m´etodo de velocidad radial. Objetivos: Recopilar informaci´onde utilidad en diferentes cat´alogospara una muestra inicial dada de 209 sistemas estelares binarios y m´ultiples,formados por una primaria de tipo espectral F, G o K y una compa~nerasecundaria de tipo M (o K tard´ıa). Comprobar si el par de estrellas forma efectivamente un par de movimiento propio y obtener calibraciones de metalicidad espectrosc´opicasy fotom´etricasen banda K a partir de estos sistemas binarios. M´etodos: La recopilaci´onde datos de cada estrella se ha realizado buscando en cat´alogosespecializados en VizieR y la bibliograf´ıa.La comprobaci´onde si las estrellas son compa~nerasde movimiento propio se ha realizado estudiando los movimientos propios de ambas estrellas con la ayuda de dos herramientas del observatorio virtual: Aladin y T opCat. A partir de una lista de sistemas aptos, se han obtenido dos tipos de calibraciones de metalicidad: espectrosc´opicas y fotom´etricas.Para derivar dichas calibraciones, se ha supuesto que la metalicidad de la primaria, calculada por el grupo de investigaci´onde la UCM dedicado a CARMENES, es igual a la de la secundaria. Resultados: Se ha obtenido una calibraci´onespectrosc´opicadependiente ´unicamente de la anchura equivalente de Na i (2.206 µm y 2.209 µm) y una fotom´etricaque mejora las publicadas hasta ahora. A su vez, se han estimado metalicidades para 134 estrellas M en sistemas m´ultiples, con un rango de metalicidad {0.9<[Fe/H]<+0.4. Conclusiones: El estudio de los sistemas lejanos y f´ısicosde esta muestra ha permitido dise~nar calibraciones de met- alicidad espectrosc´opicasy fotom´etricasen la banda K que podr´anusarse para calcular metalicidades de estrellas M aisladas. Palabras clave: Bases de datos astron´omicas| Estrellas: movimientos propios | Estrellas: tipo tard´ıo| Estrellas: compa~neras| Estrellas: metalicidad | Abstract: Context: CARMENES is a next-generation instrument being built by a consortium of German and Spanish institutions to carry out a survey of 300 M-type dwarf stars with the goal of detecting exoearths by radial-velocity measurements. Aims: To collect relevant information from different on-line catalogues for a given sample of 209 binary or multiple star systems, formed by F, G or K primary star and an M-dwarf (or late-K) companion. To prove if the pair is indeed a physical pair, to obtain different metallicity calibrations in K-band with these binary systems. Methods: The data compilation from every star has been done searching in catalogues in VizieR and the literature. In addition, physical pair checking has been done studying the collected proper motions from both stars (primary and secondary) and using two tools from the Virtual Observatory: Aladin and T opCat. From a list of suitable systems, two different types of calibrations had been obtained: spectroscopic and photometric. In order to determine these calibrations, we have considered that metallicity from the primary star, determined by the CARMENES UCM research group, is equal to the secondary star. Results: The spectroscopic calibration obtained is only dependant on the Na i (2.206 µm y 2.209 µm) equivalent width and the photometric calibration determined here improves the ones published so far. In addition, metallicities had been obtained for 134 M-dwarfs in multiple systems, in a range of -0.9<[Fe/H]<+0.4. Conclusions: The study of wide binary physical systems in our sample allows to derive spectroscopic and photometric metallicity callibrations in K-band that could be used to calculate metallicities in isolated M-dwarfs. Keywords: Astronomical data bases | Stars: proper motions | Stars: late-type | Stars: companions | Stars: metallicity 1 ´Indice 1 Introducci´on 3 1.1 CARMENES . .3 1.2 Enanas M y b´usquedade exoplanetas . .4 1.3 Sistemas, multiplicidad y movimientos propios . .5 1.4 Metalicidad . .6 1.5 Objetivos . .8 2 Recopilaci´onde datos y an´alisis 9 2.1 Muestra inicial y tipos espectrales . .9 2.2 Observatorio virtual y cat´alogos. 10 2.3 Comprobaci´onde sistemas por movimientos propios . 13 2.4 Par´ametrosde metalicidad . 15 2.4.1 Metalicidad de primarias FGK . 15 2.4.2 Anchuras equivalentes en NIR de las secundarias M . 16 2.4.3 Magnitudes fotom´etricasde las secundarias M . 16 3 Resultados y discusi´on 17 3.1 Multiplicidad y movimientos propios . 17 3.1.1 Multiplicidad de los sistemas . 17 3.1.2 Sistemas descartados . 18 3.1.3 Muestra final de estudio . 18 3.2 Calibraciones de metalicidad . 19 3.2.1 Calibraciones espectrosc´opicas . 19 3.2.2 Calibraciones fotom´etricas. 20 4 Conclusiones 24 Futuro del proyecto 24 Agradecimientos 25 Referencias 26 Apendice A Figuras 29 Apendice B Tablas 34 P´osters 78 2 1 Introducci´on 1.1 CARMENES CARMENES I (Calar Alto high-Resolution search for M-dwarfs with Exoearths with Near-infrared and optical Echelle´ Spectrographs) es un espectr´ografo´echelle de alta resoluci´onsituado en el telescopio Zeiss de 3.5 m del Observatorio de Calar Alto, a 2168 metros sobre el nivel del mar en la Sierra de los Filabres, Almer´ıa(Espa~na). El Instituto de Astrof´ısicade Andaluc´ıa(IAA) junto con el Max-Planck-Institut f¨urAstronomie (MPIA) son los encargados de operar el Centro Astron´omicoHispano-Alem´an(CAHA), donde se sit´uaCARMENES (Quirrenbach et al. 2014). Como consorcio, CARMENES est´aformado por 11 instituciones: MPIA, IAA, el Landessternwarte K¨onigsthul (LSW) de Heidelberg, el Institut de Ci`enciesde l'Espai (ICE) de Barcelona, el Institut f¨urAstrophysik G¨ottingen(IAG), la Universidad Complutense de Madrid (UCM), el Th¨uringerLandessternwarte Tautenburg (TLS), el Instituto de As- trof´ısicade Canarias (IAC), el Hamburger Sternwarte (HS), el Centro de Astrobiolog´ıa(CAB) en Madrid y el CAHA. M´asde 150 cient´ıficose ingenieros de estas instituciones han participado en el desarrollo, construcci´ony explotaci´on cient´ıficade este nuevo "cazador" de planetas. Lo que hace a CARMENES ´unicoy diferente de otros espectr´ografos´echelle de alta resoluci´ondedicados a la b´usqueda de exoplanetas, es su capacidad para observar en dos reg´ımenesde longitud de onda diferentes. As´ı,CARMENES es un espectr´ografode dos canales, uno en el visible (que cubre un rango de longitud de onda entre 520 y 960 nm en 55 ´ordenes)y otro en el infrarrojo cercano (cuyo rango cubre entre 960 y 1710 nm en 28 ´ordenes).Posee una resoluci´on de 94600 en el visible y de 80400 en el infrarrojo cercano (NIR). La calibraci´onen longitud de onda se lleva a cabo mediante un sistema de l´amparasde emisi´on(U-Ar, U-Ne y Th-Ne), adem´asde un ´etalon de Fabry-P´erotpara cada canal. La temperatura de trabajo en el visible es de 285,00±0,05 K, mientras que en el infrarrojo cercano necesita ser refrigerado hasta los 140,00±0,05 K para alcanzar una precisi´onen velocidad radial de 1 m/s. La t´ecnicaen la que CARMENES se basa para la detecci´onde exoplanetas se conoce como velocidad radial (RV, del acr´onimoen ingl´es). Este m´etodo da cuenta del efecto Doppler que se produce cuando una estrella y un objeto que la orbita, en este caso un planeta, se mueven en torno al centro de masas com´undel sistema. CARMENES est´a optimizado para operar en el infrarrojo cercano y posee una precisi´onde 1 m/s, lo que le permitir´aencontrar planetas dentro de la zona de habitabilidad de las estrellas M. Se ampliar´am´assobre este tema en la Secci´on1.2. Con motivo de la b´usquedade exoplanetas alrededor de este tipo de estrellas, se cre´ola base de datos Carmencita (CARMENes Cool dwarf Information and daTa Archive; Caballero et al. 2013 y Caballero et al. 2016). Carmencita posee aproximadamente unas 2200 enanas M y un gran n´umerode par´ametrospara cada objeto, bien extra´ıdosde la literatura o bien medidos por el consorcio. Entre los par´ametrosdestacan la informaci´onastrom´etricay cinem´aticade la enana (α, δ, µαcosδ, µδ, π, Vr, U, V , W ), tipos espectrales (desde M0.0V hasta M9.5V) e informaci´onfotom´etrica (19 bandas fotom´etricascubriendo un rango de longitudes de onda desde el ultravioleta al infrarrojo). La obtenci´onde otros par´ametroscomo metalicidades, gravedad superficial, temperatura o indicadores de actividad y edad (pEW (Hα), informaci´onde rayos X, velocidad rotacional) ha servido para seguir ampliando la informaci´onen Carmencita y poder descartar aquellas enanas no adecuadas para la b´usquedade exoplanetas con el m´etodo de la velocidad radial debido a su alta actividad, baja gravedad superficial, binarias espectrosc´opicasy rotadoras r´apidas. Otro de los aspectos importantes de Carmencita es el tratamiento de la multiplicidad de los sistemas. Respecto a esto, se ha dedicado la Secci´on1.3 para su explicaci´on. Para un mejor aprovechamiento del tiempo de observaci´onde CARMENES, se han seleccionado las ∼300 estrellas M m´asprometedoras de Carmencita. Estas ∼300 finalistas son los objetivos de observaci´ondurante las 600 noches hasta 2018 dedicadas al proyecto. Todas ellas cumplen las siguientes tres caracter´ısticas,adem´as de las expuestas anteriormente: • Deben ser observables desde Calar Alto , es decir, poseer una declinaci´on δ > {23 deg (distancia cenital z < 60 deg, masa de aire en culminaci´on < 2.0) • Deben ser las estrellas M m´asbrillantes en cada subtipo espectral.
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