LSD: Lyman-break galaxies Stellar populations and Dynamics - I. Mass, metallicity and gas atz∼ 3.1

Abstract

We present the first results of a project, Lyman‐break galaxies Stellar populations and Dynamics (LSD), aimed at obtaining spatially resolved, near‐infrared (IR) spectroscopy of a complete sample of Lyman‐break galaxies at z∼ 3. Deep observations with adaptive optics resulted in the detection of the main optical lines, such as [O ii]λ3727, Hβ and [O iii]λ5007, which are used to study sizes, star formation rates (SFRs), morphologies, gas‐phase metallicities, gas fractions and effective yields. Optical, near‐IR and Spitzer/Infrared Array Camera photometry are used to measure stellar mass. We obtain that morphologies are usually complex, with the presence of several peaks of emissions and companions that are not detected in broad‐band images. Typical metallicities are 10–50 per cent solar, with a strong evolution of the mass–metallicity relation from lower redshifts. Stellar masses, gas fraction and evolutionary stages vary significantly among the galaxies, with less massive galaxies showing larger fractions of gas. In contrast with observations in the local universe, effective yields decrease with stellar mass and reach solar values at the low‐mass end of the sample. This effect can be reproduced by gas infall with rates of the order of the SFRs. Outflows are present but are not needed to explain the mass–metallicity relation. We conclude that a large fraction of these galaxies is actively creating stars after major episodes of gas infall or merging.

Chemical abundance of z ~ 6 quasar broad-line regions in the XQR-30 sample

“…The lack of apparent redshift evolution up to 𝑧 ∼ 6 stands in contrast to studies of metallicity in star-forming galaxies and Lyman-break galaxies up to 𝑧 ∼ 3.5, which show evolution in the mass-metallicity relationship and an overall decrease in metallicity with redshift (e.g. Maiolino et al 2008;Mannucci et al 2009). It's possible to infer the host galaxy metallicity using the mass of the central black hole using the tight (0.1 dex) galaxy stellar mass -gas phase metallicity relationship (MZR) (e.g.…”

Chemical abundance of z ~ 6 quasar broad-line regions in the XQR-30 sample

“…The lack of apparent redshift evolution up to 𝑧 ∼ 6 stands in contrast to studies of metallicity in star-forming galaxies and Lyman-break galaxies up to 𝑧 ∼ 3.5, which show evolution in the mass-metallicity relationship and an overall decrease in metallicity with redshift (e.g. Maiolino et al 2008;Mannucci et al 2009). It's possible to infer the host galaxy metallicity using the mass of the central black hole using the tight (0.1 dex) galaxy stellar mass -gas phase metallicity relationship (MZR) (e.g.…”

A fundamental relation between mass, star formation rate and metallicity in local and high-redshift galaxies

“…Also galaxies at z = 3.3 can fit into this scheme, with large masses of infalling gas. This is in agreement with other recent independent results (Mannucci et al 2009; Cresci 2010). In the local universe, galaxies with large SFR are rare and often associated to merging events, and other effects become dominant which relate metallicity mainly to M ★ .…”

A fundamental relation between mass, SFR and metallicity in local and high redshift galaxies

“…Also galaxies at z=3.3 can fit into this scheme, with large masses of infalling gas. This is in agreement with other recent independent results (Mannucci et al 2009;Cresci 2010). In the local universe, galaxies with large SFR are rare and often associated to merging events, and other effects becomes dominant which relate metallicity mainly to M .…”

Chemical abundance of z ~ 6 quasar broad-line regions in the XQR-30 sample

“…The lack of apparent redshift evolution up to 𝑧 ∼ 6 stands in contrast to studies of metallicity in star-forming galaxies and Lyman-break galaxies up to 𝑧 ∼ 3.5, which show evolution in the mass-metallicity relationship and an overall decrease in metallicity with redshift (e.g. Maiolino et al 2008;Mannucci et al 2009). It's possible to infer the host galaxy metallicity using the mass of the central black hole using the tight (0.1 dex) galaxy stellar mass -gas phase metallicity relationship (MZR) (e.g.…”

A fundamental relation between mass, star formation rate and metallicity in local and high-redshift galaxies

“…Also galaxies at z = 3.3 can fit into this scheme, with large masses of infalling gas. This is in agreement with other recent independent results (Mannucci et al 2009; Cresci 2010). In the local universe, galaxies with large SFR are rare and often associated to merging events, and other effects become dominant which relate metallicity mainly to M ★ .…”

A fundamental relation between mass, SFR and metallicity in local and high redshift galaxies

“…Also galaxies at z=3.3 can fit into this scheme, with large masses of infalling gas. This is in agreement with other recent independent results (Mannucci et al 2009;Cresci 2010). In the local universe, galaxies with large SFR are rare and often associated to merging events, and other effects becomes dominant which relate metallicity mainly to M .…”

Chemical abundance of z ~ 6 quasar broad-line regions in the XQR-30 sample

“…The lack of apparent redshift evolution up to 𝑧 ∼ 6 stands in contrast to studies of metallicity in star-forming galaxies and Lyman-break galaxies up to 𝑧 ∼ 3.5, which show evolution in the mass-metallicity relationship and an overall decrease in metallicity with redshift (e.g. Maiolino et al 2008;Mannucci et al 2009). It's possible to infer the host galaxy metallicity using the mass of the central black hole using the tight (0.1 dex) galaxy stellar mass -gas phase metallicity relationship (MZR) (e.g.…”

A fundamental relation between mass, star formation rate and metallicity in local and high-redshift galaxies

“…Also galaxies at z = 3.3 can fit into this scheme, with large masses of infalling gas. This is in agreement with other recent independent results (Mannucci et al 2009; Cresci 2010). In the local universe, galaxies with large SFR are rare and often associated to merging events, and other effects become dominant which relate metallicity mainly to M ★ .…”

A fundamental relation between mass, SFR and metallicity in local and high redshift galaxies

“…Also galaxies at z=3.3 can fit into this scheme, with large masses of infalling gas. This is in agreement with other recent independent results (Mannucci et al 2009;Cresci 2010). In the local universe, galaxies with large SFR are rare and often associated to merging events, and other effects becomes dominant which relate metallicity mainly to M .…”