The MUSE-Faint survey

Astronomy and Astrophysics, vol. 678, pp. A38

Abstract

Aims. We use the stellar line-of-sight velocities of Antlia B (Ant B), a faint dwarf galaxy in the NGC 3109 association, to derive constraints on the fundamental properties of scalar field dark matter (SFDM), which was originally proposed to solve the small-scale problems faced by cold dark matter models. Methods. We used the first spectroscopic observations of Ant B, a distant (d ∼ 1.35 Mpc) faint dwarf (MV = −9.7, M⋆ ∼ 8 × 105 M⊙), from MUSE-Faint, a survey of ultra-faint dwarfs conducted using the Multi Unit Spectroscopic Explorer. By measuring the line-of-sight velocities of stars in the 1′×1′ field of view, we identified 127 stars as members of Ant B, which enabled us to model its dark matter density profile with the Jeans modelling code GRAVSPHERE. We implemented a model for SFDM into GRAVSPHERE and used this to place constraints on the self-coupling strength of this model. Results. We find a virial mass of M200 ≈ 1.66−0.92+2.51 × 109 M⊙ and a concentration parameter of c200 ≈ 17.38−4.20+6.06 for Ant B. These results are consistent with the mass-concentration relations in the literature. We constrain the characteristic length scale of the repulsive self-interaction RTF of the SFDM model to RTF ≲ 180 pc (68% confidence level), which translates to a self-coupling strength of g/m2c4 ≲ 5.2 × 10−20 eV−1 cm3. The constraint on the characteristic length scale of the repulsive self-interaction is inconsistent with the value required to match observations of the cores of dwarf galaxies in the Local Group, suggesting that the cored density profiles of those galaxies are not caused by SFDM.

Authors 10

1. Mariana P. Júlio

   Universidade do Porto · Leibniz Institute for Astrophysics Potsdam · Institute of Astrophysics and Space Sciences · Centro de Astrofísica da Universidade do Porto

   Affiliation as printed

   Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal

   Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal

   Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany

2. J. Brinchmann Aachen Leiden Observatory

   Leiden University · Universidade do Porto · Institute of Astrophysics and Space Sciences · Centro de Astrofísica da Universidade do Porto · Leiden Observatory

   Affiliation as printed

   Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal

   Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal

   Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands

3. Sebastiaan L. Zoutendijk Aachen Leiden Observatory

   Leiden University · Leiden Observatory

   Affiliation as printed

   Leiden Observatory, Leiden University, PO Box 9513 2300 RA Leiden, The Netherlands

4. Justin I. Read

   University of Surrey

   Affiliation as printed

   University of Surrey, Physics Department, Guildford GU2 7XH, UK

5. Daniel Vaz

   Universidade do Porto · Institute of Astrophysics and Space Sciences · Centro de Astrofísica da Universidade do Porto

   Affiliation as printed

   Departamento de Física e Astronomia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal

   Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal

6. Sebastian Kamann

   Liverpool John Moores University

   Affiliation as printed

   Astrophysics Research Institute, Liverpool John Moores University, IC2 Liverpool Science Park, 146 Brownlow Hill, Liverpool L35RF, UK

7. Davor Krajnović

   Leibniz Institute for Astrophysics Potsdam

   Affiliation as printed

   Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany

8. Leindert Boogaard

   Max Planck Institute for Astronomy

   Affiliation as printed

   Max Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany

9. Matthias Steinmetz

   Leibniz Institute for Astrophysics Potsdam

   Affiliation as printed

   Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany

10. N. Bouché

    Lyon 1 Université · École Normale Supérieure de Lyon · Centre National de la Recherche Scientifique · Centre de Recherche Astrophysique de Lyon

    Affiliation as printed

    Univ. Lyon, Univ. Lyon 1, ENS de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon, UMR5574, 69230 Saint-Genis-Laval, France