Upper limits on the mass and luminosity of Population III-dominated galaxies
Abstract
We here derive upper limits on the mass and luminosity of Population III (POPIII) dominated proto-galaxies based on the collapse of primordial gas under the effect of angular momentum loss via Lyα radiation drag and the gas accretion on to a galactic centre. Our model predicts that POPIII-dominated galaxies at z ∼ 7 are hosted by haloes with Mh ∼ 1.5 × 108-1.1 × 109 M⊙, that they have Lyα luminosities of LLyα ∼ 3.0 × 1042-2.1 × 1043 erg s- 1, stellar mass of Mstar ∼ 0.8 × 105-2.5 × 106 M⊙ and outflowing gas with velocities Vout ∼ 40 km s- 1 due to Lyα radiation pressure. We show that the POPIII galaxy candidate CR7 violates the derived limits on stellar mass and Lyα luminosity and thus is unlikely to be a POPIII galaxy. POPIII-dominated galaxies at z ∼ 7 have He II line emission that is ∼1-3 orders of magnitude lower than that of Lyα, they have high Lyα equivalent width of ≳ 300 Å and should be found close to bright star-forming galaxies. The He II 1640 Å line is in comfortable reach of next generation telescopes, like the James Webb Space Telescope (JWST) or Thirty Meter Telescope (TMT).
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- May 2017
- DOI:
- 10.1093/mnrasl/slw249
- arXiv:
- arXiv:1610.04249
- Bibcode:
- 2017MNRAS.467L..51Y
- Keywords:
-
- radiative transfer;
- stars: Population III;
- galaxies: evolution;
- galaxies: formation;
- galaxies: high-redshift;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 5 pages, 1 figure, accepted for publication in MNRAS Letters