The galaxy luminosity function at z ≃ 1 in the hudf: Probing the dwarf population

R. E. Ryan, N. P. Hathi, S. H. Cohen, S. Malhotra, J. Rhoads, Rogier Windhorst, T. Budavári, N. Pirzkal, C. Xu, N. Panagia, L. A. Moustakas, S. Di Serego Alighieri, H. Yan

Research output: Contribution to journalArticlepeer-review

41 Scopus citations


We present a catalog of spectrophotometric redshifts for 1308 galaxies from the Grism ACS Program for Extragalactic Science (GRAPES) observations with the Hubble Space Telescope. These low-resolution spectra between 6000 Å and 9500 Åare supplemented with U, J, H, and Ks data from various facilities, resulting in redshifts computed with ∼40 spectral bins per galaxy. For 75 galaxies in the range 0.5 < z < 1.5 with spectroscopic redshifts, the standard deviation in the fractional error in 1 + z is 0.037. With this catalog, we compute the B-band luminosity function in this redshift range from 72 galaxies. Due to the depth of the GRAPES survey, we are able to accurately constrain the faint-end slope by going to MB ≃ - 18 mag at z = 1.0 ± 0.2, nearly 2 mag fainter than previous studies. The faint-end slope is α = - 1.32 ± 0.07. When compared to numerous published values at various redshifts, we find strong evidence for a steepening of the faint-end slope with redshift, which is expected in the hierarchical formation scenario of galaxies.

Original languageEnglish (US)
Pages (from-to)839-845
Number of pages7
JournalAstrophysical Journal
Issue number2
StatePublished - Oct 20 2007


  • Catalogs
  • Galaxies: high-redshift
  • Surveys

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'The galaxy luminosity function at z ≃ 1 in the hudf: Probing the dwarf population'. Together they form a unique fingerprint.

Cite this