TY - JOUR
T1 - IMAGES
T2 - II. A surprisingly low fraction of undisturbed rotating spiral disks at z ∼ 0.6 the morpho-kinematical relation 6 Gyr ago
AU - Neichel, B.
AU - Hammer, F.
AU - Puech, M.
AU - Flores, H.
AU - Lehnert, M.
AU - Rawat, A.
AU - Yang, Y.
AU - Delgado, R.
AU - Amram, P.
AU - Balkowski, C.
AU - Cesarsky, C.
AU - Dannerbauer, H.
AU - Fuentes-Carrera, I.
AU - Guiderdoni, B.
AU - Kembhavi, A.
AU - Liang, F.
AU - Nesvadba, N.
AU - Östlin, G.
AU - Pozzetti, L.
AU - Ravikumar, C. D.
AU - Di Serego Alighieri, S.
AU - Vergani, D.
AU - Vernet, J.
AU - Wozniak, H.
PY - 2008/6
Y1 - 2008/6
N2 - We present a first combined analysis of the morphological and dynamical properties for the intermediate-mass Galaxy Evolution Sequence (IMAGES) sample. It is a representative sample of 52 z ≈ 0.6 galaxies with Mstell from 1.5 to 15×1010 M⊙ that possesses 3D resolved kinematics and HST deep imaging in at least two broad band filters. We aim at evaluating the evolution of rotating spirals robustly since z ≈ 0.6, as well as at testing the different schemes for classifying galaxies morphologically. We used all the information provided by multi-band images, color maps, and 2D light fitting to assign a morphological class to each object.We divided our sample into spiral disks, peculiar objects, compact objects, and mergers. Using our morphological classification scheme, 4/5 of the identified spirals are rotating disks, and more than 4/5 of identified peculiar galaxies show complex kinematics, while automatic classification methods such as concentration-asymmetry and GINI-M20 severely overestimate the fraction of relaxed disk galaxies. Using this methodology, we find that the fraction of undisturbed rotating spirals has increased by a factor ≈2 during the past 6 Gyr, a much higher fraction than was found previously based on morphologies alone. These rotating spiral disks are forming stars very rapidly, even doubling their stellar masses over the past 6 Gyr, while most of their stars were formed a few Gyr earlier, which reveals a large gas supply. Because they are the likely progenitors of local spirals, we can conjecture how their properties are evolving. Their disks show some evidence of inside-out growth, and the gas supply/accretion is not random since the disk needs to be stable in order to match the local disk properties.
AB - We present a first combined analysis of the morphological and dynamical properties for the intermediate-mass Galaxy Evolution Sequence (IMAGES) sample. It is a representative sample of 52 z ≈ 0.6 galaxies with Mstell from 1.5 to 15×1010 M⊙ that possesses 3D resolved kinematics and HST deep imaging in at least two broad band filters. We aim at evaluating the evolution of rotating spirals robustly since z ≈ 0.6, as well as at testing the different schemes for classifying galaxies morphologically. We used all the information provided by multi-band images, color maps, and 2D light fitting to assign a morphological class to each object.We divided our sample into spiral disks, peculiar objects, compact objects, and mergers. Using our morphological classification scheme, 4/5 of the identified spirals are rotating disks, and more than 4/5 of identified peculiar galaxies show complex kinematics, while automatic classification methods such as concentration-asymmetry and GINI-M20 severely overestimate the fraction of relaxed disk galaxies. Using this methodology, we find that the fraction of undisturbed rotating spirals has increased by a factor ≈2 during the past 6 Gyr, a much higher fraction than was found previously based on morphologies alone. These rotating spiral disks are forming stars very rapidly, even doubling their stellar masses over the past 6 Gyr, while most of their stars were formed a few Gyr earlier, which reveals a large gas supply. Because they are the likely progenitors of local spirals, we can conjecture how their properties are evolving. Their disks show some evidence of inside-out growth, and the gas supply/accretion is not random since the disk needs to be stable in order to match the local disk properties.
KW - Galaxies: evolution
KW - Galaxies: formation
KW - Galaxies: fundametal parameters
KW - Galaxies: kinematics and dynamics
UR - http://www.scopus.com/inward/record.url?scp=44349117467&partnerID=8YFLogxK
U2 - 10.1051/0004-6361:20079226
DO - 10.1051/0004-6361:20079226
M3 - Artículo
SN - 0004-6361
VL - 484
SP - 159
EP - 172
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
IS - 1
ER -