Missing dark matter in dwarf galaxies?

Oman, Kyle A.; Navarro, Julio F.; Sales, Laura V.; Fattahi, Azadeh; Frenk, Carlos S.; Sawala, Till; Schaller, Matthieu; White, Simon D. M.

doi:10.1093/mnras/stw1251

Cited by 79 publications

(82 citation statements)

References 81 publications

(141 reference statements)

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“…12 As we sill see in §IV, these models are chosen to fulfill the constraints from the observables described there and in §III D, while still being in the range of parameters of interest for solving the smallscale structure problems of CDM.…”

Section: Results: Example λSfdm Modelsmentioning

confidence: 99%

“…Eqs. (12) and (13) can also be rearranged into a useful form, in which ρ SFDM and p SFDM are related to |ψ| 2 ,…”

Section: Energy Density Contribution From Sfdmmentioning

confidence: 99%

“…First, N-body simulations of collisionless CDM predict a universal cuspy density profile for DM halos. However, measurements of the density profiles of various dark-matter-dominated systems, e.g., dwarf spheroidal galaxies, low-surface-brightness galaxies, even some galaxy clusters, have suggested shallower profiles, or even cores at their centers (the "cusp/core problem") [8][9][10][11][12]. Such N-body simulations also predict a large-overabundance of subhalos in the Local Group compared with the observed number of satellite galaxies (the "missing satellites problem") [13,14].…”

Section: Introductionmentioning

confidence: 99%

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Bose-Einstein-condensed scalar field dark matter and the gravitational wave background from inflation: New cosmological constraints and its detectability by LIGO

Shapiro

Rindler-Daller

2017

Phys. Rev. D

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We consider an alternative to WIMP cold dark matter (CDM), ultralight bosonic dark matter (m 10 −22 eV/c 2 ) described by a complex scalar field (SFDM) with a global U (1) symmetry, for which the comoving particle number density, or charge density, is conserved after particle production during standard reheating. We allow for a repulsive self-interaction. In a ΛSFDM universe, SFDM starts relativistic, evolving from stiff (w = 1) to radiation-like (w = 1/3), before becoming nonrelativistic at late times (w = 0). Thus, before the familiar radiation-dominated era, there is an earlier era of stiff-SFDM-domination. During both the stiff-SFDM-dominated and radiation-dominated eras, the expansion rate is higher than in ΛCDM. SFDM particle mass m and quartic self-interaction coupling strength λ, are therefore constrained by cosmological observables, particularly N eff , the effective number of neutrino species during BBN, and zeq, the redshift of matter-radiation equality. Furthermore, since the stochastic gravitational wave background (SGWB) from inflation is amplified during the stiff-SFDM-dominated era, it can contribute a radiationlike component large enough to affect these observables, by further boosting the expansion rate after the stiff era ends. Remarkably, this same amplification makes detection of the SGWB possible at high frequencies by current laser interferometer experiments, e.g., aLIGO/Virgo and LISA. For SFDM particle parameters that satisfy these cosmological constraints, the amplified SGWB is detectable by LIGO for a broad range of reheat temperatures T reheat , for values of the tensor-to-scalar ratio r currently allowed by CMB polarization measurements. For a given r and λ/(mc 2 ) 2 , the marginally-allowed ΛSFDM model for each T reheat has the smallest m that satisfies the cosmological constraints, and maximizes the present SGWB energy density for that T reheat . This SGWB is then maximally detectable for values of T reheat for which modes that reenter the horizon when reheating ended have frequencies today that lie within the LIGO sensitive band. For example, for the family of marginally-allowed models with r = 0.01 and λ/(mc 2 ) 2 = 10 −18 eV −1 cm 3 , the maximally detectable ΛSFDM model has T reheat ≃ 2 × 10 4 GeV and m ≃ 1.6 × 10 −19 eV/c 2 , for which we predict an aLIGO O1 run detection with signal-to-noise ratio of ∼ 10. We show that the null detection of the SGWB recently reported by the aLIGO O1 run excludes the parameter range 8.75 × 10 3 T reheat (GeV) 1.7 × 10 5 for this illustrative family at 95% confidence, thereby demonstrating that GW detection experiments can already place a new kind of cosmological constraint on SFDM. A wider range of SFDM parameters and reheat temperatures should be accessible to aLIGO/Virgo O5, with the potential to detect this unique signature of the ΛSFDM model. For this same illustrative family, for example, a 3σ detection is predicted for 600 T reheat (GeV) 10 7 .

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Section: Results: Example λSfdm Modelsmentioning

confidence: 99%

“…Eqs. (12) and (13) can also be rearranged into a useful form, in which ρ SFDM and p SFDM are related to |ψ| 2 ,…”

Section: Energy Density Contribution From Sfdmmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Bose-Einstein-condensed scalar field dark matter and the gravitational wave background from inflation: New cosmological constraints and its detectability by LIGO

Shapiro

Rindler-Daller

2017

Phys. Rev. D

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“…This implies that the mass profile of the lens model is solely determined by baryon which dominates over the dark matter. Such dark matter deficiency reminds us of 'missing dark matter' in some dwarf galaxies (Oman et al 2016).…”

Section: Discussionmentioning

confidence: 99%

Evidence for a Dusty Dark Dwarf Galaxy in the Quadruple Lens MG 0414+0534

Inoue

Matsushita

Minezaki

2017

ApJL

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We report the 4 σ detection of a faint object with a flux of ∼ 0.3 mJy, in the vicinity of the quadruply lensed QSO MG 0414+0534 using the Atacama Large Millimeter/submillimeter array (ALMA) Band 7. The object is most probably a dusty dark dwarf galaxy, which has not been detected in either the optical, near-infrared (NIR) or radio (cm) bands. An anomaly in the flux ratio of the lensed images observed in Band 7 and the mid-infrared (MIR) band and the reddening of the QSO light color can be simultaneously explained if we consider the object as a lensing substructure with an ellipticity ∼ 0.7 at a redshift of 0.5 z 1. Using the best-fit lens models with three lenses, we find that the dark matter plus baryon mass associated with the object is ∼ 10 9 M ⊙ , the dust mass is ∼ 10 7 M ⊙ and the linear size is 5 kpc. Thus our findings suggest that the object is a dusty dark dwarf galaxy. A substantial portion of faint submillimeter galaxies (SMGs) in the universe may be attributed to such dark objects.

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“…13). The inset shows the current data for IC 2574 and the APOSTLE simulation result for it (reproduced with permission from Oman et al 2016). Right: a similar plot which collects older data (de Blok et al 2001;de Blok and Bosma 2002;Swaters et al 2003), the data from Oh et al (2011), data based on stellar and gas velocity dispersions (Adams et al 2014), and the selected data for 15 galaxies from Oh et al (2015) These observations can now be compared with modified predictions of the ΛCDM theory of galaxy formation and evolution, where star formation and feedback have been added to the ingredients ("subgrid physics") of the numerical simulations.…”

Section: The Core-cusp Problemmentioning

confidence: 99%

Hi in the Outskirts of Nearby Galaxies

Bosma

2017

Astrophysics and Space Science Library

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The HI in disk galaxies frequently extends beyond the optical image, and can trace the dark matter there. I briefly highlight the history of high spatial resolution HI imaging, the contribution it made to the dark matter problem, and the current tension between several dynamical methods to break the disk-halo degeneracy. I then turn to the flaring problem, which could in principle probe the shape of the dark halo. Instead, however, a lot of attention is now devoted to understanding the role of gas accretion via galactic fountains. The current Λ cold dark matter theory has problems on galactic scales, such as the core-cusp problem, which can be addressed with HI observations of dwarf galaxies. For a similar range in rotation velocities, galaxies of type Sd have thin disks, while those of type Im are much thicker. After a few comments on modified Newtonian dynamics and on irregular galaxies, I close with statistics on the HI extent of galaxies.

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Missing dark matter in dwarf galaxies?

Cited by 79 publications

References 81 publications

Bose-Einstein-condensed scalar field dark matter and the gravitational wave background from inflation: New cosmological constraints and its detectability by LIGO

Bose-Einstein-condensed scalar field dark matter and the gravitational wave background from inflation: New cosmological constraints and its detectability by LIGO

Evidence for a Dusty Dark Dwarf Galaxy in the Quadruple Lens MG 0414+0534

Hi in the Outskirts of Nearby Galaxies

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