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 H α is still one

We present the final global design and performances of EMIR, the NIR multiobject spectrograph of the GTC, as well as the plan for its early scientific exploitation. EMIR, currently in the middle of its final phase, will be one of the first common user instruments for the GTC, the 10 meter telescope under construction by GRANTECAN at the Roque de

ELMER is a visible imager-spectrograph currently scheduled to be in operation at the GTC on Day One. The design phase of the ELMER Structure and Mechanisms ended on November 2002. Since then, after manufacturing and mechanical integration, an exhaustive test campaign at factory was carried out. We present the fabrication and assembly highlights and

ELMER is a multi-purpose Camera&Spectrograph in the optical range for the GTC. ELMERs electro-mechanical design was based in well known, straightforward and reliable solutions, hence each mechanism is based in a wheel driven by a pre-loaded worm gear transmission, except focusing of the focal plane on the CCD which is based in a translation stage

We have analyzed spectroscopic earthshine data to determine Earth's nightly spectral albedos covering the visible, near and middle infrared spectral ranges. Observations in the visible were undertaken from Palomar Observatory with the spectrograph in the Palomar 60" telescope and with the echelle spectrograph of the InfraRed Telescope Facility

We present ESO-NTT low resolution spectroscopy of the neutron star X-ray transient Cen X-4 in quiescence over a complete orbital cycle. Our data reveal the presence of a K3-7 V companion which contributes 63% to the 5600-6900 Å flux and orbits the neutron star with a velocity semi-amplitude of K_2=145.8± 1.0 km s-1. This, combined with a previous