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The stellar mass-halo mass relation of isolated field dwarfs : A critical test of ΛCDM at the edge of galaxy formation

Read, J. I. ; Iorio, G. ; Agertz, O. LU and Fraternali, F. (2017) In Monthly Notices of the Royal Astronomical Society 467(2). p.2019-2038
Abstract

We fit the rotation curves of isolated dwarf galaxies to directly measure the stellar mass-halo mass relation (M*-M200) over the mass range 5 × 105 ≲ M*/M⊙ ≲ 108. By accounting for cusp-core transformations due to stellar feedback, we find a monotonic relation with little scatter. Such monotonicity implies that abundance matching should yield a similar M*- M200 if the cosmological model is correct. Using the 'field galaxy' stellar mass function from the Sloan Digital Sky Survey (SDSS) and the halo mass function from the Λ cold dark matter Bolshoi simulation, we find remarkable agreement between the two. This holds down to M200 ~ 5 × 109 M⊙, and to... (More)

We fit the rotation curves of isolated dwarf galaxies to directly measure the stellar mass-halo mass relation (M*-M200) over the mass range 5 × 105 ≲ M*/M⊙ ≲ 108. By accounting for cusp-core transformations due to stellar feedback, we find a monotonic relation with little scatter. Such monotonicity implies that abundance matching should yield a similar M*- M200 if the cosmological model is correct. Using the 'field galaxy' stellar mass function from the Sloan Digital Sky Survey (SDSS) and the halo mass function from the Λ cold dark matter Bolshoi simulation, we find remarkable agreement between the two. This holds down to M200 ~ 5 × 109 M⊙, and to M200 ~ 5 × 108 M⊙ if we assume a power-law extrapolation of the SDSS stellar mass function below M* ~ 107 M⊙. However, if instead of SDSS we use the stellar mass function of nearby galaxy groups, then the agreement is poor. This occurs because the group stellar mass function is shallower than that of the field below M* ~ 109 M⊙, recovering the familiar 'missing satellites' and 'too big to fail' problems. Our result demonstrates that both problems are confined to group environments and must, therefore, owe to 'galaxy formation physics' rather than exotic cosmology. Finally, we repeat our analysis for aΛWarm Dark Matter cosmology, finding that it fails at 68 per cent confidence for a thermal relic mass of mWDM < 1.25 keV, and mWDM < 2 keV if we use the power-law extrapolation of SDSS. We conclude by making a number of predictions for future surveys based on these results.

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author
; ; and
publishing date
type
Contribution to journal
publication status
published
keywords
Cosmological parameters, Dark matter, Galaxies: dwarf, Galaxies: irregular, Galaxies: kinematics and dynamics, Local Group
in
Monthly Notices of the Royal Astronomical Society
volume
467
issue
2
pages
20 pages
publisher
Oxford University Press
external identifiers
  • scopus:85018253871
ISSN
0035-8711
DOI
10.1093/mnras/stx147
language
English
LU publication?
no
id
d1df3469-b3ce-4be6-9a46-38e31827ba3d
date added to LUP
2019-02-07 11:10:15
date last changed
2022-04-25 21:00:03
@article{d1df3469-b3ce-4be6-9a46-38e31827ba3d,
  abstract     = {{<p>We fit the rotation curves of isolated dwarf galaxies to directly measure the stellar mass-halo mass relation (M*-M<sub>200</sub>) over the mass range 5 × 10<sup>5</sup> ≲ M*/M<sub>⊙</sub> ≲ 10<sup>8</sup>. By accounting for cusp-core transformations due to stellar feedback, we find a monotonic relation with little scatter. Such monotonicity implies that abundance matching should yield a similar M*- M<sub>200</sub> if the cosmological model is correct. Using the 'field galaxy' stellar mass function from the Sloan Digital Sky Survey (SDSS) and the halo mass function from the Λ cold dark matter Bolshoi simulation, we find remarkable agreement between the two. This holds down to M<sub>200</sub> ~ 5 × 10<sup>9</sup> M<sub>⊙</sub>, and to M<sub>200</sub> ~ 5 × 10<sup>8</sup> M<sub>⊙</sub> if we assume a power-law extrapolation of the SDSS stellar mass function below M* ~ 10<sup>7</sup> M<sub>⊙</sub>. However, if instead of SDSS we use the stellar mass function of nearby galaxy groups, then the agreement is poor. This occurs because the group stellar mass function is shallower than that of the field below M* ~ 10<sup>9</sup> M<sub>⊙</sub>, recovering the familiar 'missing satellites' and 'too big to fail' problems. Our result demonstrates that both problems are confined to group environments and must, therefore, owe to 'galaxy formation physics' rather than exotic cosmology. Finally, we repeat our analysis for aΛWarm Dark Matter cosmology, finding that it fails at 68 per cent confidence for a thermal relic mass of mWDM &lt; 1.25 keV, and mWDM &lt; 2 keV if we use the power-law extrapolation of SDSS. We conclude by making a number of predictions for future surveys based on these results.</p>}},
  author       = {{Read, J. I. and Iorio, G. and Agertz, O. and Fraternali, F.}},
  issn         = {{0035-8711}},
  keywords     = {{Cosmological parameters; Dark matter; Galaxies: dwarf; Galaxies: irregular; Galaxies: kinematics and dynamics; Local Group}},
  language     = {{eng}},
  month        = {{01}},
  number       = {{2}},
  pages        = {{2019--2038}},
  publisher    = {{Oxford University Press}},
  series       = {{Monthly Notices of the Royal Astronomical Society}},
  title        = {{The stellar mass-halo mass relation of isolated field dwarfs : A critical test of ΛCDM at the edge of galaxy formation}},
  url          = {{http://dx.doi.org/10.1093/mnras/stx147}},
  doi          = {{10.1093/mnras/stx147}},
  volume       = {{467}},
  year         = {{2017}},
}