FeII/MgII Emission Line Ratio in High Redshift Quasars

TY - JOUR

T1 - FeII/MgII Emission Line Ratio in High Redshift Quasars

AU - Dietrich, M.

AU - Hamann, F.

AU - Appenzeller, I.

AU - Vestergaard, Marianne

PY - 2003/6/27

Y1 - 2003/6/27

N2 - We present results of the analysis of near infrared spectroscopic observations of 6 high-redshift quasars (z > 4), emphasizing the measurement of the ultraviolet FeII/MgII emission line strength in order to estimate the beginning of intense star formation in the early universe. To investigate the evolution of the FeII/MgII ratio over a wider range in cosmic time, we measured this ratio for composite quasar spectra which cover a redshift range of 0 4 quasars must have started already at an epoch corresponding to z_f = 6 to 9, when the age of the universe was ~0.5 Gyr (H_o = 72 km/s/Mpc, Omega_M = 0.3, Omega_Lambda = 0.7). This epoch corresponds well to the re-ionization era of the universe.

AB - We present results of the analysis of near infrared spectroscopic observations of 6 high-redshift quasars (z > 4), emphasizing the measurement of the ultraviolet FeII/MgII emission line strength in order to estimate the beginning of intense star formation in the early universe. To investigate the evolution of the FeII/MgII ratio over a wider range in cosmic time, we measured this ratio for composite quasar spectra which cover a redshift range of 0 4 quasars must have started already at an epoch corresponding to z_f = 6 to 9, when the age of the universe was ~0.5 Gyr (H_o = 72 km/s/Mpc, Omega_M = 0.3, Omega_Lambda = 0.7). This epoch corresponds well to the re-ionization era of the universe.

KW - astro-ph

U2 - 10.1086/378045

DO - 10.1086/378045

M3 - Journal article

SN - 0004-637X

VL - 596

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2

M1 - 817

ER -