A fundamental plane for field star-forming galaxies

Scritto in Pubblicazioni

Context. Star formation rate (SFR), metallicity, and stellar mass are among the most important parameters of star-forming (SF) galaxies characterizing their formation and evolution. They are known to be related to each other both at low and high redshift in the mass-metallicity, mass-SFR, and metallicity-SFR relations. <BR /> Aims: We demonstrate the existence of a plane in a 3D parameter space defined by the axes SFR [log (SFR)(M<SUB>ȯ</SUB> yr<SUP>-1</SUP>)] , gas metallicity [12 + log (O/H)], and stellar mass [log (M<SUB>star</SUB>/M<SUB>ȯ</SUB>)] of SF galaxies. <BR />...

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The Peculiar Optical Spectrum of 4C+22.25: Imprint of a Massive Black Hole Binary?

Scritto in Pubblicazioni

We report the discovery of peculiar features in the optical spectrum of 4C+22.25, a flat spectrum radio quasar at z = 0.4183 observed in the Sloan Digital Sky Survey and in a dedicated spectroscopic follow-up from the Nordic Optical Telescope. The Hβ and Hα lines show broad profiles (FWHM ~ 12,000 km s<SUP>-1</SUP>), faint fluxes, and extreme offsets (Δv = 8700 ± 1300 km s<SUP>-1</SUP>) with respect to the narrow emission lines. These features show no significant variation in a time lag of ~3.1 yr (rest frame). We rule out possible interpretations based on the superposition of two...

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2003 QZ30

Scritto in Pubblicazioni

Available from the Minor Planet Center.
Available from the Minor Planet Center.