Lyman Break Galaxies and the Star Formation Rate of the Universe at z~6

Preprint, Article English OPEN
Stanway, Elizabeth ; Bunker, Andrew ; McMahon, Richard (2003)
  • Publisher: Oxford University Press
  • Related identifiers: doi: 10.1046/j.1365-8711.2003.06546.x
  • Subject: QB | QC | Astrophysics
    arxiv: Astrophysics::Galaxy Astrophysics | Astrophysics::Cosmology and Extragalactic Astrophysics | Astrophysics::High Energy Astrophysical Phenomena | Astrophysics::Earth and Planetary Astrophysics | Astrophysics::Solar and Stellar Astrophysics

We determine the space density of UV-luminous star-burst galaxies at z~6 using deep HST ACS SDSS-i' (F775W) and SDSS-z' (F850LP) and VLT ISAAC J and K_s band imaging of the Chandra Deep Field South. We find 8 galaxies and one star with (i'-z')>1.5 to a depth of z'{AB}= 25.6 (an 8-sigma detection in each of the 3 available ACS epochs). This corresponds to an unobscured star formation rate of ~15M_sun/yr/h{70}^2 at z=5.8, equivalent to L* for the Lyman break population at z =3-4 (Omega_{Lambda}=0.7, Omega_M=0.3). We are sensitive to star forming galaxies at 5.6<z<7.0 with an effective comoving volume of \~1.8x10^5 Mpc^3/h{70}^3 after accounting for incompleteness at the higher redshifts due to luminosity bias. This volume should encompass the primeval sub-galactic scale fragments of the progenitors of about a thousand L* galaxies at the current epoch. We determine a volume-averaged global star formation rate of (6.7 +/- 2.7)x10^{-4}h{70}M_sun/yr/Mpc^3 at z~6 from rest-frame UV selected star-bursts at the bright end of the luminosity function: this is a lower limit because of dust obscuration and galaxies below our sensitivity limit. This measurement shows that at z~6 the star formation density at the bright end is a factor of ~6 times less than that determined by Steidel et al. (1999) for a comparable sample of UV selected galaxies at z=3-4, and so extends our knowledge of the star formation history of the Universe to earlier times than previous work and into the epoch where reionization may have occurred.
  • References (36)
    36 references, page 1 of 4

    Becker R. H. et al., 2001, AJ, 122, 2850

    Bertin E., Arnouts S., 1996, A&AS, 117, 393

    Bunker A. J., Stanway E. R., Ellis R. S., McMahon R. G., McCarthy P. J., 2003, preprint (astro-ph/0302401)

    Cimatti A. et al., 2002, A&A, 381, L68

    Coleman G. D., Wu C.-C., Weedman D. W., 1980, ApJS, 43, 393

    Cowie L. L., Songaila A., Hu E. M., Cohen J. G., 1996, AJ, 112, 839

    Dawson S., Stern D., Bunker A., Spinrad H., Dey A., 2001, AJ, 122, 598

    Dickinson M., Giavalisco M., 2002, in Bender R., Renzini A., eds, ESO Astrophys. Symp. Ser., The Mass of Galaxies at Low and High Redshift. Springer-Verlag, Berlin, p. 324

    Dickinson M. et al., 2000, ApJ, 531, 624

    Fan X. et al., 2001, AJ, 122, 2833

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