%0 Journal Article
%A Pérez Calpena, Ana
%A Sánchez-Blanco Mancera, Ernesto
%A Gómez Álvarez, Pedro
%A Martínez Delgado, Ismael
%A Castillo Morales, África
%A Gil de Paz, Armando
%A Arrillaga, Xabier, Xabier
%A García Vargas, Marisa Luisa
%A Gallego Maestro, Jesús
%A Carrasco Licea, Esperanza
%A Iglesias Páramo, Jorge;, Jorge
%A Cedazo, Raquel
%T MEGARA MOS: where are my positioners and fibers pointing to?
%D 2018
%@ 0277-786X
%U https://hdl.handle.net/20.500.14352/18696
%X MEGARA is an integral-field and multi-object medium-resolution spectrograph for the GTC 10.4m telescope, which was commissioned on June - August 2017. MEGARA offers two observing modes, the LCB mode, a large central IFU; and a Multi-Object Spectrograph (MOS) mode, composed by 92 robotic positioners carrying 7-fiber minibundles each. This paper presents the models and measurements developed for the alignment between the image of the telescope pupil and the 100-itm fiber cores during the integration and verification at the laboratory. On the one hand, the error in the positioner-minibundles assembly was optimized with the aim of achieving a fiber-to-fiber flux homogeneity better than 10%. On the other hand, the positioner pointing was characterized in order to achieve a pointing precision of 1/5 of the spaxel size (which has been designed to be 0.62 arcsec). The on-sky measurements obtained during the commissioning to verify our laboratory results are also presented.
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