TY - JOUR
T1 - The history of star formation in galaxy disks in the local volume as measured by the advanced camera for surveys nearby galaxy survey treasury
AU - Williams, Benjamin F.
AU - Dalcanton, Julianne J.
AU - Johnson, L. C.
AU - Weisz, Daniel R.
AU - Seth, Anil C.
AU - Dolphin, Andrew
AU - Gilbert, Karoline M.
AU - Skillman, Evan
AU - Rosema, Keith
AU - Gogarten, Stephanie M.
AU - Holtzman, Jon
AU - De Jong, Roelof S.
PY - 2011/6/10
Y1 - 2011/6/10
N2 - We present a measurement of the age distribution of stars residing in spiral disks and dwarf galaxies. We derive a complete star formation history of the ∼ 140Mpc3 covered by the volume-limited sample of galaxies in the Advanced Camera for Surveys (ACS) Nearby Galaxy Survey Treasury (ANGST). The total star formation rate density history (ρSFR(t)) is dominated by the large spirals in the volume, although the sample consists mainly of dwarf galaxies. Our ρSFR(t) shows a factor of ∼ 3 drop at z ∼ 2, in approximate agreement with results from other measurement techniques. While our results show that the overall ρSFR(t) has decreased since z ∼ 1, the measured rates during this epoch are higher than those obtained from other measurement techniques. This enhanced recent star formation rate appears to be largely due to an increase in the fraction of star formation contained in low-mass disks at recent times. Finally, our results indicate that despite the differences at recent times, the epoch of formation of ∼ 50% of the stellar mass in dwarf galaxies was similar to that of ∼ 50% of the stellar mass in large spiral galaxies (z ≳ 2), despite the observed galaxy-to-galaxy diversity among the dwarfs.
AB - We present a measurement of the age distribution of stars residing in spiral disks and dwarf galaxies. We derive a complete star formation history of the ∼ 140Mpc3 covered by the volume-limited sample of galaxies in the Advanced Camera for Surveys (ACS) Nearby Galaxy Survey Treasury (ANGST). The total star formation rate density history (ρSFR(t)) is dominated by the large spirals in the volume, although the sample consists mainly of dwarf galaxies. Our ρSFR(t) shows a factor of ∼ 3 drop at z ∼ 2, in approximate agreement with results from other measurement techniques. While our results show that the overall ρSFR(t) has decreased since z ∼ 1, the measured rates during this epoch are higher than those obtained from other measurement techniques. This enhanced recent star formation rate appears to be largely due to an increase in the fraction of star formation contained in low-mass disks at recent times. Finally, our results indicate that despite the differences at recent times, the epoch of formation of ∼ 50% of the stellar mass in dwarf galaxies was similar to that of ∼ 50% of the stellar mass in large spiral galaxies (z ≳ 2), despite the observed galaxy-to-galaxy diversity among the dwarfs.
KW - cosmology: observations
KW - galaxies: evolution
KW - galaxies: stellar content
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U2 - 10.1088/2041-8205/734/1/L22
DO - 10.1088/2041-8205/734/1/L22
M3 - Review article
AN - SCOPUS:79959466791
SN - 2041-8205
VL - 734
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 1 PART 2
M1 - L22
ER -