A companion to a quasar at redshift 4.7

There is a growing consensus that the emergence of quasars at high redshifts is related to the onset of galaxy formation, suggesting that the detection of concentrations of gas accompanying such quasars should provide clues about the early history of galaxies. Quasar companions have been recently identified at redshifts up to $z \approx 3$. Here we report observations of Lyman-$\alpha$ emission (a tracer of ionised hydrogen) from the companion to a quasar at $z$=4.702, corresponding to a time when the Universe was less than ten per cent of its present age. We argue that most of the emission arises in a gaseous nebula that has been photoionised by the quasar, but an additional component of continuum light -perhaps quasar light scattered from dust in the companion body, or emission from young stars within the nebula- appears necessary to explain the observations. These observations may be indicative of the first stages in the assembly of galaxy-sized structures.Comment: 8 pages, 4 figures, plain LaTeX. Accepted for publication in Natur

Molecular gas and dust around a radio-quiet quasar at redshift 4.69.

Galaxies are believed to have formed a large proportion of their stars in giant bursts of star formation early in their lives, but when and how this took place are still very uncertain. The presence of large amounts of dust in quasars and radio galaxies at redshifts z > 4 shows that some synthesis of heavy elements had already occurred at this time. This implies that molecular gas--the building material of stars--should also be present, as it is in galaxies at lower redshifts (z approximately = 2.5, refs 7-10). Here we report the detection of emission from dust and carbon monoxide in the radio-quiet quasar BR1202 - 0725, at redshift z = 4.69. Maps of these emissions reveal two objects, separated by a few arc seconds, which could indicated either the presence of a companion to the quasar or gravitational lensing of the quasar itself. Regardless of the precise interpretation of the maps, the detection of carbon monoxide confirms the presence of a large mass of molecular gas in one of the most distant galaxies known, and shows that conditions conducive to huge bursts of star formation existed in the very early Universe

The Maunakea Spectroscopic Explorer Book 2018

(Abridged) This is the Maunakea Spectroscopic Explorer 2018 book. It is intended as a concise reference guide to all aspects of the scientific and technical design of MSE, for the international astronomy and engineering communities, and related agencies. The current version is a status report of MSE's science goals and their practical implementation, following the System Conceptual Design Review, held in January 2018. MSE is a planned 10-m class, wide-field, optical and near-infrared facility, designed to enable transformative science, while filling a critical missing gap in the emerging international network of large-scale astronomical facilities. MSE is completely dedicated to multi-object spectroscopy of samples of between thousands and millions of astrophysical objects. It will lead the world in this arena, due to its unique design capabilities: it will boast a large (11.25 m) aperture and wide (1.52 sq. degree) field of view; it will have the capabilities to observe at a wide range of spectral resolutions, from R2500 to R40,000, with massive multiplexing (4332 spectra per exposure, with all spectral resolutions available at all times), and an on-target observing efficiency of more than 80%. MSE will unveil the composition and dynamics of the faint Universe and is designed to excel at precision studies of faint astrophysical phenomena. It will also provide critical follow-up for multi-wavelength imaging surveys, such as those of the Large Synoptic Survey Telescope, Gaia, Euclid, the Wide Field Infrared Survey Telescope, the Square Kilometre Array, and the Next Generation Very Large Array.Comment: 5 chapters, 160 pages, 107 figure

The E-ELT first light spectrograph HARMONI: capabilities and modes

Trabajo presentado en SPIE Astronomical Telescopes, celebrado en San Diego (California), del 26 de junio al 1 de julio de 2016HARMONI is the E-ELT's first light visible and near-infrared integral field spectrograph. It will provide four different spatial scales, ranging from coarse spaxels of 60 × 30 mas best suited for seeing limited observations, to 4 mas spaxels that Nyquist sample the diffraction limited point spread function of the E-ELT at near-infrared wavelengths. Each spaxel scale may be combined with eleven spectral settings, that provide a range of spectral resolving powers (R 3500, 7500 and 20000) and instantaneous wavelength coverage spanning the 0.5 - 2.4 ¿m wavelength range of the instrument. In autumn 2015, the HARMONI project started the Preliminary Design Phase, following signature of the contract to design, build, test and commission the instrument, signed between the European Southern Observatory and the UK Science and Technology Facilities Council. Crucially, the contract also includes the preliminary design of the HARMONI Laser Tomographic Adaptive Optics system. The instrument's technical specifications were finalized in the period leading up to contract signature. In this paper, we report on the first activity carried out during preliminary design, defining the baseline architecture for the system, and the trade-off studies leading up to the choice of baseline

FRANÇOIS GONNESSIAT: UN CANDIDATO IDEAL PARA APOYAR A LA MISIÓN GEODÉSICA FRANCESA EN ECUADOR

The essay presents an approach to the Second French Geodetic Mission carried out in Ecuador between 1901-1906. For the execution of this scientific presence, of great international interest, previous in- tergovernmental procedures were carried out in 1899, between the French charge d’affaires, Hipólito Frandin, and the president of Ecuador Eloy Alfaro, who to grant the total administration of the As- tronomical Observatory of Quito, France had to bear the costs of the astronomer’s installation. This essay provides interesting insights into the life of a young astronomer scientist who participated in the organization of the Lyon laboratory and, for his work and experience in high precision astron- omy, in 1889, he obtained the Lalande Prize awarded by the Acad- emy of Sciences of Paris and in 1894 the international recognition, therefore, and with this background, Gonnessiat, turned out to be the ideal candidate to launch the observatory bought from France at the time of the presidential administration of García Moreno. The essay addresses the work of this character as a scientist and as sup- port in some of the administrative processes of the Mission before the Ecuadorian authorities.El ensayo presenta un enfoque de la Segunda Misión Geodésica Francesa realizada en el Ecuador entre 1901-1906. Para la ejecución de esta presencia científica, de gran interés internacional, se realizaron trámites previos intergubernamentales en 1899, entre el encargado de negocios de Francia, Hipólito Frandin, y el presidente de Ecuador Eloy Alfaro, quien para conceder la administración total del Observatorio astronómico de Quito, Francia debía asumir los costos de la instalación del astrónomo. Este ensayo aporta con interesantes conocimientos sobre la vida de un joven científico astrónomo que participó en la organización del laboratorio de Lyon y, por su trabajo y experiencia en astronomía de alta precisión, en 1889, obtuvo el premio Lalande otorgado por la Academia de Ciencias de París y en 1894 el reconocimiento internacional, por lo tanto, y con estos antecedentes, Gonnessiat, resultaba ser el candidato ideal para poner en marcha el observatorio comprado a Francia en la época de la administración presidencial de García Moreno. El ensayo aborda la labor de este personaje como científico y como apoyo en algunos de los procesos administrativos de la Misión ante las autoridades ecuatorianas

Etude du spectrographe intégral de champ à trame de micro-lentilles Tiger

Study of the integral field spectrograph TigerLa méthode classique de spectrographie à fente longue interdit l'exploitation de la haute résolution spatiale aujourd'hui accessible par les télescopes modernes. Cette méthode a, de plus, l'inconvénient majeur de n'acquérir l'information spatiale que sur une seule dimension, rendant impossible les cartographies bidimensionnelles des grandeurs physiques mesurables (vitesses, dispersions, densité, température). Le spectrographe intégral de champ Tiger est basé sur le découpage du champ par une trame de micro-lentilles. Il offre une solution efficace et élégante au problème de la spectrographie bidimensionnelle sur un champ uniformément échantillonné avec une résolution spatiale limitée par la turbulence atmosphérique. L’étude détaillée de cet instrument est présentée, après avoir rappelé les principales méthodes de la spectrographie bidimensionnelle en astronomie. Les premiers résultats obtenus sur les galaxies de Seyfert NGC 5728 et NGC 1068 sont présentés dans la dernière section de cette thèse. Dans le premier cas, il s'agit de la détection d'un noyau de Seyfert 1 dans une Seyfert 2, venant à l'appui des schémas unificateurs de ces deux types d'objets. L’observation de NGC 1068 porte sur l'environnement de la source radio et son interaction avec le gaz ionise. On montre une corrélation du gaz à grande vitesse avec l'élongation radio, ainsi qu'une augmentation du niveau d'ionisation dans la même direction. Des arguments sont présentés en faveur d'un front de choc entre le lobe radio et le gaz

Introduction

Figure 1. Adolphe Gouhenant en 1843 Source : Conseil départemental de la Haute-Garonne/Archives départementales/37 FI 19/ Dessin de Léon Soulié. Le nom « Adolphe Gouhenant » sera peut-être familier à ceux qui ont étudié l’histoire du Nord Texas, ou le mouvement social français du xixe siècle. On le trouve dans plusieurs ouvrages traitant des socialismes utopiques et spécialement du communisme icarien, et sa notice biographique figure dans le célèbre Maitron. Aux États-Unis, il apparaît sous ..

Un temple pour les arts et les sciences

J’ai voulu bâtir un temple pour les arts et les sciences ; j’ai voulu embellir la ville que j’habite ; j’ai voulu en écarter la foudre. J’y ai employé tous mes soins, mon temps et toute ma fortune. Je suis presque arrivé à la fin de mon projet je n’ai plus qu’un pas à faire : c’est le plus difficile.François Ignace Gouhenant, 1831 Un garçon élevé à l’ombre de la Révolution (1804-1824) En 1814, l’Empire napoléonien chancelait sous les coups de la coalition européenne et une invasion militaire ..

Des jours sombres

Je l’ai fait placer à côté de la tombe du Major Arnold, sur un des points culminants de ma propriété.Adolphe Gouhenant, novembre 1856 Une famille déchirée (1856) Ernest Humbert passa trois ans entre Dallas et Fort Worth. Les lettres adressées à sa famille restée à Flagy ont permis de combler quelques lacunes dans l’histoire de la vie de son oncle Poupon. Ernest lui-même joua un rôle important dans cette vie. En mai 1857, Gouhenant reçut une lettre de sa sœur Marguerite, qu’elle avait rédigée ..