### Resumen

We measure the average mass properties of a sample of 41 strong gravitational lenses at moderate redshift (z 0.4-0.9) and present the lens redshift for six of these galaxies for the first time. Using the techniques of strong and weak gravitational lensing on archival data obtained from the Hubble Space Telescope, we determine that the average mass overdensity profile of the lenses can be fit with a power-law profile (ΔΣ ∞ R ^{-0.86 0.16}) that is within 1σ of an isothermal profile (ΔΣ ∞ R ^{-1}) with velocity dispersion σ_{v} = 260 20 km s^{-1}. Additionally, we use a two-component de Vaucouleurs + Navarro-Frenk-White (NFW) model to disentangle the total mass profile into separate luminous and dark matter components and determine the relative fraction of each component. We measure the average rest frame V-band stellar mass-to-light ratio (Υ_{V} = 4.0 ± 0.6 h M _{⊙}/L _{⊙}) and virial mass-to-light ratio (τ_{V} = 300 ± 90 h M _{⊙}/L _{⊙}) for our sample, resulting in a virial-to-stellar mass ratio of M _{vir}/M _{*} = 75 25. Relaxing the NFW assumption, we estimate that changing the inner slope of the dark matter profile by 20% yields a 30% change in stellar mass-to-light ratio. Finally, we compare our results to a previous study using low-redshift lenses to understand how galaxy mass profiles evolve over time. We investigate the evolution of M _{vir}/M _{*}(z) = α(1 + z)^{β}, and find best-fit parameters of α = 51 36 and β = 0.9 ± 1.8, constraining the growth of virial-to-stellar mass ratio over the last ∼7 Gyr. We note that, by using a sample of strong lenses, we are able to constrain the growth of M _{vir}/M _{*}(z) without making any assumptions about the initial mass function of the stellar population.

Idioma original | English |
---|---|

Páginas (desde-hasta) | 1579-1595 |

Número de páginas | 17 |

Publicación | Astrophysical Journal |

Volumen | 716 |

N.º | 2 |

DOI | |

Estado | Published - 2010 |

### Huella dactilar

### ASJC Scopus subject areas

- Nuclear and High Energy Physics
- Space and Planetary Science
- Astronomy and Astrophysics

### Citar esto

*Astrophysical Journal*,

*716*(2), 1579-1595. https://doi.org/10.1088/0004-637X/716/2/1579

}

*Astrophysical Journal*, vol. 716, n.º 2, pp. 1579-1595. https://doi.org/10.1088/0004-637X/716/2/1579

**Cosmic evolution of virial and stellar mass in massive early-type galaxies.** / Lagattuta, David J.; Fassnacht, Christopher D.; Auger, Matthew W.; Marshall, Philip J.; Brada, Marua; Treu, Tommaso; Gavazzi, Raphal; Schrabback, Tim; Faure, Cécile; Anguita, Timo.

Resultado de la investigación: Article

TY - JOUR

T1 - Cosmic evolution of virial and stellar mass in massive early-type galaxies

AU - Lagattuta, David J.

AU - Fassnacht, Christopher D.

AU - Auger, Matthew W.

AU - Marshall, Philip J.

AU - Brada, Marua

AU - Treu, Tommaso

AU - Gavazzi, Raphal

AU - Schrabback, Tim

AU - Faure, Cécile

AU - Anguita, Timo

PY - 2010

Y1 - 2010

N2 - We measure the average mass properties of a sample of 41 strong gravitational lenses at moderate redshift (z 0.4-0.9) and present the lens redshift for six of these galaxies for the first time. Using the techniques of strong and weak gravitational lensing on archival data obtained from the Hubble Space Telescope, we determine that the average mass overdensity profile of the lenses can be fit with a power-law profile (ΔΣ ∞ R -0.86 0.16) that is within 1σ of an isothermal profile (ΔΣ ∞ R -1) with velocity dispersion σv = 260 20 km s-1. Additionally, we use a two-component de Vaucouleurs + Navarro-Frenk-White (NFW) model to disentangle the total mass profile into separate luminous and dark matter components and determine the relative fraction of each component. We measure the average rest frame V-band stellar mass-to-light ratio (ΥV = 4.0 ± 0.6 h M ⊙/L ⊙) and virial mass-to-light ratio (τV = 300 ± 90 h M ⊙/L ⊙) for our sample, resulting in a virial-to-stellar mass ratio of M vir/M * = 75 25. Relaxing the NFW assumption, we estimate that changing the inner slope of the dark matter profile by 20% yields a 30% change in stellar mass-to-light ratio. Finally, we compare our results to a previous study using low-redshift lenses to understand how galaxy mass profiles evolve over time. We investigate the evolution of M vir/M *(z) = α(1 + z)β, and find best-fit parameters of α = 51 36 and β = 0.9 ± 1.8, constraining the growth of virial-to-stellar mass ratio over the last ∼7 Gyr. We note that, by using a sample of strong lenses, we are able to constrain the growth of M vir/M *(z) without making any assumptions about the initial mass function of the stellar population.

AB - We measure the average mass properties of a sample of 41 strong gravitational lenses at moderate redshift (z 0.4-0.9) and present the lens redshift for six of these galaxies for the first time. Using the techniques of strong and weak gravitational lensing on archival data obtained from the Hubble Space Telescope, we determine that the average mass overdensity profile of the lenses can be fit with a power-law profile (ΔΣ ∞ R -0.86 0.16) that is within 1σ of an isothermal profile (ΔΣ ∞ R -1) with velocity dispersion σv = 260 20 km s-1. Additionally, we use a two-component de Vaucouleurs + Navarro-Frenk-White (NFW) model to disentangle the total mass profile into separate luminous and dark matter components and determine the relative fraction of each component. We measure the average rest frame V-band stellar mass-to-light ratio (ΥV = 4.0 ± 0.6 h M ⊙/L ⊙) and virial mass-to-light ratio (τV = 300 ± 90 h M ⊙/L ⊙) for our sample, resulting in a virial-to-stellar mass ratio of M vir/M * = 75 25. Relaxing the NFW assumption, we estimate that changing the inner slope of the dark matter profile by 20% yields a 30% change in stellar mass-to-light ratio. Finally, we compare our results to a previous study using low-redshift lenses to understand how galaxy mass profiles evolve over time. We investigate the evolution of M vir/M *(z) = α(1 + z)β, and find best-fit parameters of α = 51 36 and β = 0.9 ± 1.8, constraining the growth of virial-to-stellar mass ratio over the last ∼7 Gyr. We note that, by using a sample of strong lenses, we are able to constrain the growth of M vir/M *(z) without making any assumptions about the initial mass function of the stellar population.

KW - Dark matter

KW - Galaxies: elliptical and lenticular, cD

KW - Galaxies: evolution

KW - Galaxies: structure

KW - Gravitational lensing: strong

KW - Gravitational lensing: weak

UR - http://www.scopus.com/inward/record.url?scp=77953161402&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/716/2/1579

DO - 10.1088/0004-637X/716/2/1579

M3 - Article

AN - SCOPUS:77953161402

VL - 716

SP - 1579

EP - 1595

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

ER -