TY - JOUR
T1 - IMAGES IV
T2 - Strong evolution of the oxygen abundance in gaseous phases of intermediate mass galaxies from z ∼ 0.8
AU - Rodrigues, M.
AU - Hammer, F.
AU - Flores, H.
AU - Puech, M.
AU - Liang, Y. C.
AU - Fuentes-Carrera, I.
AU - Nesvadba, N.
AU - Lehnert, M.
AU - Yang, Y.
AU - Amram, P.
AU - Balkowski, C.
AU - Cesarsky, C.
AU - Dannerbauer, H.
AU - Delgado, R.
AU - Guiderdoni, B.
AU - Kembhavi, A.
AU - Neichel, B.
AU - Östlin, G.
AU - Pozzetti, L.
AU - Ravikumar, C. D.
AU - Rawat, A.
AU - Di Serego Alighieri, S.
AU - Vergani, D.
AU - Vernet, J.
AU - Wozniak, H.
PY - 2008/12
Y1 - 2008/12
N2 - Context. Intermediate mass galaxies (> 1010 M⊙) at z ∼ 0.6 are the likeliest progenitors of the present-day, numerous population of spirals. There is growing evidence that they have evolved rapidly in the last 6 to 8 Gyr, and likely already have formed a significant fraction of their stellar mass, often showing perturbed morphologies and kinematics.Aims. We have gathered a representative sample of 88 such galaxies and have provided robust estimates of their gas phase metallicity.Methods. We used moderate spectral resolution spectroscopy at VLT/FORS2 with an unprecedentedly high S/N allowing us to remove biases coming from interstellar absorption lines and extinction, to establish robust values of R23 = ([OII]λ3727 + [OIII]λλ4959, 5007)/HΒ.Results. We definitively confirm that the predominant population of z ∼ 0.6 starbursts and luminous IR galaxies (LIRGs) are on average two times less metal rich than the local galaxies at a given stellar mass. We do find that the metal abundance of the gaseous phase of galaxies evolves linearly with time, from z = 1 to z = 0 and after comparing with other studies, from z = 3 to z = 0. Combining our results with the reported evolution of the Tully Fisher relation, we find that such an evolution requires that ∼30% of the stellar mass of local galaxies have been formed through an external supply of gas, thus excluding the closed box model. Distant starbursts & LIRGs have properties (metal abundance, star formation efficiency & morphologies) similar to those of local LIRGs. Their underlying physics is likely dominated by gas infall, probably through merging or interactions. Conclusions. Our study further supports the rapid evolution of z ∼ 0.4-1 galaxies. Gas exchange between galaxies is likely the main cause of this evolution.
AB - Context. Intermediate mass galaxies (> 1010 M⊙) at z ∼ 0.6 are the likeliest progenitors of the present-day, numerous population of spirals. There is growing evidence that they have evolved rapidly in the last 6 to 8 Gyr, and likely already have formed a significant fraction of their stellar mass, often showing perturbed morphologies and kinematics.Aims. We have gathered a representative sample of 88 such galaxies and have provided robust estimates of their gas phase metallicity.Methods. We used moderate spectral resolution spectroscopy at VLT/FORS2 with an unprecedentedly high S/N allowing us to remove biases coming from interstellar absorption lines and extinction, to establish robust values of R23 = ([OII]λ3727 + [OIII]λλ4959, 5007)/HΒ.Results. We definitively confirm that the predominant population of z ∼ 0.6 starbursts and luminous IR galaxies (LIRGs) are on average two times less metal rich than the local galaxies at a given stellar mass. We do find that the metal abundance of the gaseous phase of galaxies evolves linearly with time, from z = 1 to z = 0 and after comparing with other studies, from z = 3 to z = 0. Combining our results with the reported evolution of the Tully Fisher relation, we find that such an evolution requires that ∼30% of the stellar mass of local galaxies have been formed through an external supply of gas, thus excluding the closed box model. Distant starbursts & LIRGs have properties (metal abundance, star formation efficiency & morphologies) similar to those of local LIRGs. Their underlying physics is likely dominated by gas infall, probably through merging or interactions. Conclusions. Our study further supports the rapid evolution of z ∼ 0.4-1 galaxies. Gas exchange between galaxies is likely the main cause of this evolution.
KW - Galaxies: ISM
KW - Galaxies: evolution
KW - Galaxies: spiral
KW - Galaxies: starburst
KW - Infrared: galaxies
UR - http://www.scopus.com/inward/record.url?scp=57349185981&partnerID=8YFLogxK
U2 - 10.1051/0004-6361:200810435
DO - 10.1051/0004-6361:200810435
M3 - Artículo
SN - 0004-6361
VL - 492
SP - 371
EP - 388
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
IS - 2
ER -