The Low Mass End of the Fundamental Relation for Gravitationally Lensed Star Forming Galaxies at 1 < z < 6

Lise Christensen (1) , Johan Richard (2) , Jens Hjorth (1) , Bo Milvang-Jensen (1) , Peter Laursen (1) , Marceau Limousin (3) , Miroslava Dessauges-Zavadsky (4) , Claudio Grillo (1) , Harald Ebeling (5)

1 DARK - Dark Cosmology Centre
2 CRAL - Centre de Recherche Astrophysique de Lyon
3 LAM - Laboratoire d'Astrophysique de Marseille
4 ObsGE - Observatoire Astronomique de l'Université de Genève
5 Institute for Astronomy [Honolulu]

We present VLT/X-shooter spectra of 13 galaxies in the redshift range 1< z < 6, which are strongly lensed by massive galaxy clusters. Spectroscopic redshifts are measured for nine galaxies, while three sources have redshifts determined from continuum breaks in their spectra. The stellar masses of the galaxies span four orders of magnitude between 10^7 and 10^11 M_sun and have luminosities at 1500 A rest-frame between 0.004 and 9 L^* after correcting for the magnification. This allows us to probe a variety of galaxy types from young, low-mass starburst galaxies to massive evolved galaxies. The lensed galaxies with stellar masses less than 10^10 M_sun have a large scatter compared to the fundamental relation between stellar mass, star formation rates and oxygen abundances. We provide a modified fit to the fundamental relation for low-mass, low-metallicity galaxies with a weaker dependence of the metallicity on either the star formation rate or stellar mass compared to low-redshift, high-mass and high-metallicity SDSS galaxies.

Mots clés: Astrophysics; Cosmology and Extragalactic Astrophysics

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Cosmologie et astrophysique extra-galactique [astro-ph.CO]

Lise Christensen, Johan Richard, Jens Hjorth, Bo Milvang-Jensen, Peter Laursen, et al.. The Low Mass End of the Fundamental Relation for Gravitationally Lensed Star Forming Galaxies at 1 < z < 6. Astronomy and Astrophysics - A&A, 2012, 1209, pp.767. ⟨hal-00766096⟩