Site Map
Contacts
Follow us on Facebook Follow us on Twitter YouTube channel
Centro de Astrofísica da Universidade do Porto

Systematics of the ultraviolet rising flux in a GALEX/SDSS sample of early-type galaxies

M. R. Rich, S. Salim, J. Brinchmann, S. Charlot, M. Seiberg, G. Kauffmann, Y. Lee, S. K. Yi, T. A. Barlow, L. Bianchi, Y. Byun, J. Donas, K. Forster, P. G. Friedman, T. Heckman, P. N. Jelinsky, B. F. Madore, R. F. Malina, C. D. Martin, B. Milliard, P. Morrissey, S. G. Neff, D. Schiminovich, O. H. W. Siegmund, T. Small, A. S. Szalay, B. Y. Welsh, T. K. Wyder

Abstract
We present ultraviolet photometry for a sample of morphologically early-type galaxies selected by matching the Sloan Digital Sky Survey (SDSS) First Data Release with the Galaxy Evolution Explorer (GALEX) Medium and All-sky Imaging Surveys. We obtain a working sample of 1032 early-type galaxies with GALEX far-UV (FUV) detections, SDSS spectroscopy, and z〈0.2. Using the SDSS spectra to identify galaxies with even weak star formation or evidence of active galactic nuclei, and further removing galaxies with any evidence of non-early-type morphology, we derive a final sample of 172 red quiescent early-type galaxies. We find that the FUV-r color has a full range of 5 mag. Plotting the FUV-r color against the metallicity sensitive Lick Mg2 and D4000 indices and against the stellar velocity dispersion, we find no correlation between our measurement of UV rising flux and any parameter sensitive to the global metallicity of quiescent early-type galaxies.

The Astrophysical Journal Letters
Volume 619, Page L107
January 2005

>> ADS

Institute of Astrophysics and Space Sciences

Institute of Astrophysics and Space Sciences (IA) is a new but long anticipated research infrastructure with a national dimension. It embodies a bold but feasible vision for the development of Astronomy, Astrophysics and Space Sciences in Portugal, taking full advantage and fully realizing the potential created by the national membership of the European Space Agency (ESA) and the European Southern Observatory (ESO). IA resulted from the merging the two most prominent research units in the field in Portugal: the Centre for Astrophysics of the University of Porto (CAUP) and the Center for Astronomy and Astrophysics of the University of Lisbon (CAAUL). It currently hosts more than two-thirds of all active researchers working in Space Sciences in Portugal, and is responsible for an even greater fraction of the national productivity in international ISI journals in the area of Space Sciences. This is the scientific area with the highest relative impact factor (1.65 times above the international average) and the field with the highest average number of citations per article for Portugal.

Proceed on CAUP's website|Go to IA website