The universe at z > 5: When and how did the “dark age” end?

This paper considers how the first subgalactic structures produced the UV radiation that ionized the intergalactic medium before z = 5 and the “feedback” effects of the UV radiation on structure formation. The first “pregalaxies” may eventually be detectable by their direct UV emission, with characteristic spectral features at Lyman α; high-z supernovae may also be detectable. Other probes of the intergalactic medium beyond z = 5, and of the epochs of reheating and reionization, are discussed, along with possible links between the diffusion of pregalactic metals and the origin of magnetic fields.

Measuring the topology of the universe

Observations of microwave background fluctuations can yield information not only about the geometry of the universe but potentially about the topology of the universe. If the universe is negatively curved, then the characteristic scale for the topology of the universe is the curvature radius. Thus, if we are seeing the effects of the geometry of the universe, we can hope to soon see signatures of the topology of the universe. The cleanest signature of the topology of the universe is written on the microwave sky: There should be thousands of pairs of matched circles. These circles can be used to determine the precise topology and volume of the universe. Because we see hundreds of slices through the fundamental domain of the universe, we can use the microwave observations to reconstruct the initial conditions of the entire universe on the scale of a few megaparsecs.

Emission-line galaxy surveys with GTC: The Hα Universe

Emission line galaxies are the most easily detected and studied objects in the high redshift Universe. They are being used to trace the evolution of critical observables of the Universe such as Star Formation Rate densities, starburst properties and abundances. Most of the research is being done using [OII]3727 and UV lines, but Hα is still one the best tracers for Star Formation Rate and physical properties of current star-forming galaxies. As a complementary contribution to studies of galaxy evolution, our team has focused into a long-term project to study the population of Hα-selected star-forming galaxies of the Universe at different redshifts. In 1995 we first determined the local Hα luminosity function, and from it the Star Formation Rate density (SFRd) of the local Universe. We then, using narrow-band imaging in the optical, extended this measurement to z ≃ 0.24 and z ≃ 0.4. Working in the near-infrared, GTC will be a very powerful tool to study the evolution of the Hα emission-line galaxy populations at different redshifts. We will both quantify the SFRd evolution and characterize the star-forming galaxy populations by directly comparing the same observables at all redshifts up to z ≃ 2.5.

Multiwavelength study of star-forming galaxies in the local Universe

We have studied in detail the properties of local active star-forming galaxies from the UCM survey, and in particular their star-formation histories. We have quantified the relative importance of the current episode of star formation in comparison to the underlying older stellar populations. We have also determined the total stellar mass function and burst mass function for the UCM sample using the M/L calculated for each galaxy. Integrating this mass function we obtained the contribution of the star-forming galaxies to the total stellar mass density of the local Universe.

The identity of sociology or what to do when the universe is unknown: qualitative solutions against the quantitative obsession

Social Sciences can, on occasions, be similar to the so called “hard” sciences. However, in many cases, neither the object nor the classical methods fit in with the objectives of the work. The object requires methodological and technical adjustments, which are often avoided by means of an improper rigidity of the object’s needs. These adjustments can even alter the original research idea. The main objective of this article consists of proving that those objects of study, less suitable to be addressed by rigid positivistic strategies, can be approached both scientifically and sociologically. This can be achieved with the use of different strategies and flexible methodologies to ensure validity and reliability standards. This paper will be posed, firstly, a reflection on the epistemological nature of the debate about the rigid-flexible perspectives. Secondly, the strategies and tools used by the research team to achieve the reduction of the uncertainty about the size and characteristics of the population studied will be described. Finally, some of the survey results obtained in this project will be compared to those provided by the FAMILITUR Survey (2008), conducted by the Spanish Institute of Tourist Studies (IET).

The universe we live in;

Mode of access: Internet.

The universe and life

"Second printing, January, 1934."

The universe and life

Mode of access: Internet.

The substance of The riddle of the universe,

Mode of access: Internet.

Child and universe,

Mode of access: Internet.

The scale of the universe, by Harlow Shapley ... and Heber D. Curtis.

Mode of access: Internet.

ROSAT : an international mission exploring the high energy universe.

Mode of access: Internet.

Cosmos: a sketch of a physical description of the universe.

Mode of access: Internet.

A pluralistic universe : Hibbert lectures at Manchester college on the present situation in philosophy /

I. The types of philosophic thinking.--II. Monistic idealism.III. Hegel and his method.--IV. Bergson and his critique of intellectualism.--VII. The continuity of experience.--VIII. Conclusions. Notes.--Appendices. A. The thing and its relations. B. The experience of activity. C. On the notion of reality as changing.-- Index.

Fugitive essays, upon interesting and useful subjects, relating to the early history of Ohio : its geology and agriculture, with a biography of the first successful constructor of steamboats ; a dissertation upon the antiquity of the material universe, and other articles, being a reprint from various periodicals of the day /

Mode of access: Internet.