Protogalactic starbursts at high redshift

Raul Jimenez, Paolo Padoan, James S. Dunlop, David V. Bowen, Mika Juvela, Francesca Matteucci

Research output: Contribution to journalArticlepeer-review

16 Scopus citations


We have computed the evolving ultraviolet-millimeter spectral energy distribution (SED) produced by protogalactic starbursts at high redshift, incorporating the chemical evolution of the interstellar medium in a consistent manner. Dust extinction is calculated in a novel way that is not based on empirical calibrations of extinction curves, but rather on the lifetime of molecular clouds which delays the emergence of each successive generation of stars at ultraviolet wavelengths by typically 15 Myr. The predicted restframe far-infrared-to-millimeter-wave emission includes the calculation of molecular emission-line luminosities (12CO and O2 among other molecules) consistent with the evolving chemical abundances. Here we present details of this new model along with the results of comparing its predictions with several high-redshift observables, namely, the ultraviolet SEDs of Lyman limit galaxies, the high-redshift radio galaxies 4C 41.17 and 8C 1435, the SCUBA submillimeter survey of the Hubble Deep Field (HDF), and the SEDs of intermediate-redshift elliptical galaxies. With our new reddening method, we are able to fit the spectrum of the Lyman limit galaxy 1512-cB58, and we find an extinction of about 1.9 mag at 1600 Å. This extinction applies to starbursts with spectral slope α in the range 0 ≲ α ≲ 1.5. The model also predicts that most Lyman limit galaxies should have a value of α inside that range, as is observed. The 850 μm flux density of a typical Lyman limit galaxy is expected to be only ≃ 0.5 mJy, and therefore the optical counterparts of the most luminous submillimeter sources in the HDF (or any other currently feasible submillimeter survey) are unlikely to be Lyman break galaxies. The passive evolution of our starburst model is also compared with Keck observations of the reddest known elliptical galaxy at z ∼ 1.5 and with the SED of a typical nearby elliptical galaxy. The SED of the high-redshift elliptical is nicely matched by the starburst model with an age of 4 Gyr and the SED of the nearby elliptical galaxy with an age of 13 Gyr.

Original languageEnglish (US)
Pages (from-to)152-169
Number of pages18
JournalAstrophysical Journal
Issue number1 PART 1
StatePublished - Mar 20 2000

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • Galaxies: evolution
  • Galaxies: formation
  • Galaxies: ISM
  • Galaxies: starburst
  • Galaxies: stellar content
  • Submillimeter


Dive into the research topics of 'Protogalactic starbursts at high redshift'. Together they form a unique fingerprint.

Cite this