The baryonic content and Tully-Fisher relation at z~0.6 - Astrophysics > Cosmology and Nongalactic AstrophysicsReportar como inadecuado

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Abstract: abr. Using the multi-integral-field spectrograph GIRAFFE at VLT, weprevisouly derived the stellar-mass Tully-Fisher Relation smTFR at z~0.6, andfound that the distant relation is systematically offset by roughly a factor oftwo toward lower masses. We extend the study of the evolution of the TFR byestablishing the first distant baryonic TFR. To derive gas masses in distantgalaxies, we estimate a gas radius and invert the Schmidt-Kennicutt law betweenstar formation rate and gas surface densities. We find that gas extends fartherout than the UV light from young stars, a median of ~30%. We present the firstbaryonic TFR bTFR ever established at intermediate redshift and show that,within an uncertainty of +-0.08 dex, the zeropoint of the bTFR does not appearto evolve between z~0.6 and z=0. The absence of evolution in the bTFR over thepast 6 Gyr implies that no external gas accretion is required for distantrotating disks to sustain star formation until z=0 and convert most of theirgas into stars. Finally, we confirm that the larger scatter found in thedistant smTFR, and hence in the bTFR, is caused entirely by major mergers. Thisscatter results from a transfer of energy from bulk motions in the progenitors,to random motions in the remnants, generated by shocks during the merging.Shocks occurring during these events naturally explain the large extent ofionized gas found out to the UV radius in z~0.6 galaxies. All the resultspresented in this paper support the ``spiral rebuilding scenario- of Hammerand collaborators, i.e., that a large fraction of local spiral disks have beenreprocessed during major mergers in the past 8 Gyr.

Autor: M. Puech 1, F. Hammer 1, H. Flores 1, R. Delgado-Serrano 1, M. Rodrigues 1, Y. Yang 1, 1 GEPI Observatoire de Paris Meudon


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