2004/03/23 by F. La Franca, C. Gruppioni, I. Matute +19
Physics and Astronomy · #Active galactic nucleus #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Flux (metallurgy) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Luminosity #Luminous infrared galaxy #Physics #Population #Radio Astronomy Observations and Technology #Spectral energy distribution #Star formation #Stellar population #astro-ph
paper · pdf · doi:10.1086/420987
published as Astron.J. 127 (2004) 3075 · Scheduled on AJ, Vol. 127/6, 2004 June. Table 2 (+ 15um sources coordinates) at http://www.fis.uniroma3.it/~ELAIS_S/lafrancabab.tab2.dat . Table 3 at http://www.fis.uniroma3.it/~ELAIS_S/lafrancabab.tab3.dat . Other related data and papers at http://www.fis.uniroma3.it/~ELAIS_S/ . Few luminosities in Table 2 corrected
arxiv created 2004/03/23 · openalex publication_date 2004/06/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We present a multiwavelength catalog (15 μm, R -band, K -band, and 1.4 GHz flux) plus spectroscopic identifications for 406 15 μm sources detected in the European Large Area ISO Survey (ELAIS) region S1, over the flux density range 0.5 < S 15μm < 150 mJy. Three hundred thirty-two (∼82%) sources are optically identified down to R ∼ 23.0. Spectra or bona fide stellar identifications are obtained for 290 objects (∼88% of the optically identified sources). The areal coverage, mid-infrared (MIR) and optical completeness of the sample are discussed in order to allow statistical and evolutionary analyses. Two main spectroscopic classes have been found to dominate the MIR extragalactic population: z < 0.5 star-forming galaxies [from absorbed to extreme starbursts: ν L ν (15 μm) ≈ 10 8 –10 11 L ⊙ ], which account for ∼75% of the sources, and active galactic nuclei (AGNs; both type 1 and 2), which account for ∼25% of the sources. About 20% of the extragalactic sources are dust-enshrouded starburst galaxies [e(a) spectra], and all the starburst galaxies appear more dust-extincted in the optical than nearby normal galaxies. We also identified 91 stellar objects (∼22% of the MIR sources). The counts for starburst galaxies and AGNs down to 0.6 mJy have been derived. A general trend is found in the optical-MIR spectral energy distribution of the galaxies, where the MIR-luminous objects have larger MIR to optical luminosity ratios. Based on a variety of analyses, we suggest that the ELAIS sources fainter than R ∼ 23 are luminous and ultraluminous MIR galaxies (LIG-ULIGs; ν L ν (15 μm) = 10 11 –10 12 L ⊙ ) at intermediate redshifts ( z = 0.5–1.5), and that consequently the present sample is virtually 100% spectroscopically complete up to z = 0.5.