Speaker
Description
The GALaxy Evolution eXplorer (GALEX) satellite imaged the sky at
ultraviolet wavelengths over 2003-13, making a well-cited catalogue.
It also took wide-field spectra of 125,000 objects over 0.75% of the
sky, which are under-exploited.
To make the spectra useful, we present results from a project to
categorize and collect complementary multiband data for approximately
11,000 extragalactic sources in 211 GALEX spectroscopic fields which
overlap the Sloan Digital Sky Survey (SDSS). We will provide a useful
searchable database of GALEX UV spectra (R~100-200) of extragalactic
sources. For all extragalactic sources (known or classified by us)
with GALEX spectra, we have assembled complementary images and
photometry in FUV+NUV from GALEX, in ugriz from the SDSS, in JHK from
the Two Micron All Sky Survey (2MASS) and in W1-W4 from the Wide-field
Infrared Survey Explorer (WISE), and created spectral energy
distributions (SEDs). We have also logged SIMBAD and SDSS object
classification, redshift and angular size information, and provide
some indication of spectral data quality, since it largely varies
across the sample and even across the wavelength range of individual
spectra, owing to the grism observing strategy (Bianchi et al. 2018,
Astrophys. Space Sci., 363, 56).
The UV spectral database consists of 1820 quasars, 2274
star-forming galaxies, 6327 quiescent spirals and 386 ellipticals.
The mean redshifts for quasars, star-forming galaxies, quiescent
spirals and ellipticals are 0.99, 0.07, 0.35 and 0.05 respectively.
We will show representative spectra, SEDs and color-magnitude
diagrams. The database (Pritchard et al., in preparation) will be made
publicly available from the Mikulski Archive for Space Telescopes
(STScI's MAST) as a High-Level Science Product (HLSP), as well as from
Vizier.