Keck spectroscopy and nicmos photometry of a redshift z = 5.60 galaxy

Ray J. Weymann, Daniel Stern, Andrew Bunker, Hyron Spinrad, Frederic H. Chaffee, Rodger I. Thompson, Lisa J. Storrie-Lombardi

Research output: Contribution to journalArticlepeer-review

102 Scopus citations


We present Keck Low Resolution Imaging Spectrometer spectroscopy along with Near-Infrared Camera and Multiobject Spectrometer (NICMOS) F110W (∼J) and F160W (∼H) images of the galaxy HDF 4-473.0 in the Hubble Deep Field (HDF), with a detection of an emission line consistent with Lyα at a redshift of z = 5.60. Attention to this object as a high-redshift galaxy was first drawn by Lanzetta, Yahil, & Fernandez-Soto and appeared in their initial list of galaxies with redshifts estimated from the Wide Field Planetary Camera 2 (WFPC2) HDF photometry. It was selected by us for spectroscopic observation, along with others in the HDF, on the basis of the NICMOS F110W and F160W and WFPC2 photometry. ForH0 = 65 km s-1 Mpc-1 and q0 = 0.125, the use of simple evolutionary models along with the F814W (∼I), F110W, and F160W magnitudes allow us to estimate the star formation rate (∼13 M yr-1). The colors suggest a reddening of E(B - V) ∼ 0.06. The measured flux in the Lyα line is approximately 1.0 × 10-17 ergs cm-2 s-1, and the rest-frame equivalent width, correcting for the absorption caused by intervening H I, is ∼90 Å. The galaxy is compact and regular, but resolved, with an observed FWHM of ∼0″.44. Simple evolutionary models can accurately reproduce the colors, and these models predict the Lyα flux to within a factor of 2. Using this object as a template shifted to higher redshifts, we calculate the magnitudes through the F814W and two NICMOS passbands for galaxies at redshifts 6 < z < 10.

Original languageEnglish (US)
Pages (from-to)L95-L98
JournalAstrophysical Journal
Issue number2 PART II
StatePublished - 1998


  • Early universe
  • Galaxies: distances and redshifts
  • Galaxies: evolution
  • Galaxies: formation

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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