The local high-velocity tail and the Galactic escape speed

Deason, Alis J.; Fattahi, Azadeh; Belokurov, Vasily; Evans, N. W.; Grand, Robert J. J.; Marinacci, Federico; Pakmor, Rüdiger

doi:10.1093/mnras/stz623

Cited by 119 publications

(145 citation statements)

References 85 publications

(172 reference statements)

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“…Using this method, Piffl et al (2014) −0.24 ×10 12 M ⊙ . When better accounting for biases, especially those affecting the halos that are dominated by early mergers, by using simulations from Grand et al (2019), Deason et al (2019) get an increased value of M vir,200 = 1.29 +0.37 −0.47 ×M ⊙ . We note that since all these five virial masses are at an overdensity of 200, so need to be multiplied by about 1.19 to compare the other virial masses cited, see Bland-Hawthorn & Gerhard (2016).…”

Section: Comparison With Previous Resultsmentioning

confidence: 99%

The mass of our Galaxy from satellite proper motions in the Gaia era

Fritz

Cintio

Battaglia

et al. 2020

Monthly Notices of the Royal Astronomical Society

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We use Gaia DR2 systemic proper motions of 45 satellite galaxies to constrain the mass of the Milky Way using the scale free mass estimator of Watkins et al. (2010). We first determine the anisotropy parameter β, and the tracer satellites' radial density index γ to be β=−0.67 +0.45 −0.62 and γ = 2.11 ± 0.23. When we exclude possible former satellites of the Large Magellanic Cloud, the anisotropy changes to β=−0.21 +0.37 −0.51 . We find that the index of the Milky Way's gravitational potential α, which is dependent on the mass itself, is the parameter with the largest impact on the mass determination. Via comparison with cosmological simulations of Milky Way-like galaxies, we carried out a detailed analysis of the estimation of the observational uncertainties and their impact on the mass estimator. We found that the mass estimator is biased when applied naively to the satellites of simulated Milky Way halos. Correcting for this bias, we obtain for our Galaxy a mass of 0.58 +0.15 −0.14 × 10 12 M ⊙ within 64 kpc, as computed from the inner half of our observational sample, and 1.43 +0.35 −0.32 ×10 12 M ⊙ within 273 kpc, from the full sample; this latter value extrapolates to a virial mass of M vir =1.51 +0.45 −0.40 ×10 12 M ⊙ corresponding to a virial radius of R vir =308±29 kpc. This value of the Milky Way mass lies in-between other mass estimates reported in the literature, from various different methods.

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Section: Comparison With Previous Resultsmentioning

confidence: 99%

The mass of our Galaxy from satellite proper motions in the Gaia era

Fritz

Cintio

Battaglia

et al. 2020

Monthly Notices of the Royal Astronomical Society

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“…For our study, including the CGM does not significantly alter the inferred DM halo mass or concentration since these are mostly determined by the stellar circular velocity curve -see discussion in Section 5. However, the CGM does affect, at the ∼5 percent level, the total mass within the radius, R200, as well as the escape velocity at the Sun's position, which is determined by the total mass profile out to a distance of 2R200 (see Deason et al 2019b).…”

Section: Circumgalactic Mediummentioning

confidence: 99%

“…The potential depends on the mass profile of the halo up to 2R200 and thus modelling the DM halo as a contracted or an NFW profile can introduce different biases from those present in enclosed mass measurements. These are studied in Figure 9, where we show the inferred DM halo properties using the recent measurement of the escape velocity at the position of the Sun, Vesc = (528 ± 25) km s −1 , by Deason et al (2019b). Figure 9 shows that using a NFW profile instead of a contracted NFW halo also leads to biases in modelling the escape velocity.…”

Section: Biases In Inferred Halo Propertiesmentioning

confidence: 99%

“…Eadie & Harris 2016;Posti & Helmi 2019;Watkins et al 2019) and satellite galaxies (e.g. Watkins et al 2010;Li et al 2017;Patel et al 2017;Callingham et al 2019b), high velocity stars (e,g, Smith et al 2007;Piffl et al 2014;Fragione & Loeb 2017;Rossi et al 2017;Deason et al 2019b), the orbits of tidal streams (e.g. Gibbons et al 2014;Bowden et al 2015), the luminosity function of the MW satellites (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…Constraints on the mass and concentration of the MW DM halo inferred from the escape velocity measurement ofDeason et al (2019b). The blue shaded region shows the 68 percentile confidence region when modelling the halo as an NFW profile.…”

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confidence: 99%

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The milky way total mass profile as inferred from Gaia DR2

Cautun

Benítez-Llambay

Deason

et al. 2020

Monthly Notices of the Royal Astronomical Society

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We determine the Milky Way (MW) mass profile inferred from fitting physically motivated models to the Gaia DR2 Galactic rotation curve and other data. Using various hydrodynamical simulations of MW-mass haloes, we show that the presence of baryons induces a contraction of the dark matter (DM) distribution in the inner regions, r 20 kpc. We provide an analytic expression that relates the baryonic distribution to the change in the DM halo profile. For our galaxy, the contraction increases the enclosed DM halo mass by factors of roughly 1.3, 2 and 4 at radial distances of 20, 8 and 1 kpc, respectively compared to an uncontracted halo. Ignoring this contraction results in systematic biases in the inferred halo mass and concentration. We provide a best-fitting contracted NFW halo model to the MW rotation curve that matches the data very well. The best-fit has a DM halo mass, M DM 200 = 0.99 +0.18 −0.20 ×10 12 M , and concentration before baryon contraction of 8.2 +1.7 −1.5 , which lie close to the median halo mass-concentration relation predicted in ΛCDM. The inferred total mass, M total 200 = 1.12 +0.20 −0.22 × 10 12 M , is in good agreement with recent measurements. The model gives a MW stellar mass of 4.99 +0.34 −0.50 × 10 10 M , of which 60% is contained in the thin stellar disc, with a bulge-to-total ratio of 0.2. We infer that the DM density at the Solar position is ρ DM = 9.0 +0.5 −0.4 × 10 −3 M pc −3 ≡ 0.34 +0.02 −0.02 GeV cm −3 . The rotation curve data can also be fitted with an uncontracted NFW halo model, but with very different DM and stellar parameters. The observations prefer the physically motivated contracted NFW halo, but the measurement uncertainties are too large to rule out the uncontracted NFW halo.

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Dark matter substructures affect dark matter-electron scattering in xenon-based direct detection experiments

Maity

Laha

2023

J. High Energ. Phys.

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Recent sky surveys have discovered a large number of stellar substructures. It is highly likely that there are dark matter (DM) counterparts to these stellar substructures. We examine the implications of DM substructures for electron recoil (ER) direct detection (DD) rates in dual phase xenon experiments. We have utilized the results of the LAMOST survey and considered a few benchmark substructures in our analysis. Assuming that these substructures constitute 10% of the local DM density, we study the discovery limits of DM-electron scattering cross sections considering one kg-year exposure and 1, 2, and 3 electron thresholds. With this exposure and threshold, it is possible to observe the effect of the considered DM substructure for the currently allowed parameter space. We also explore the sensitivity of these experiments in resolving the DM substructure fraction. For all the considered cases, we observe that DM having mass $$ \mathcal{O}(10) $$ O 10 MeV has a better prospect in resolving substructure fraction as compared to $$ \mathcal{O}(100) $$ O 100 MeV scale DM. We also find that within the currently allowed DM-electron scattering cross-section; these experiments can resolve the substructure fraction (provided it has a non-negligible contribution to the local DM density) with good accuracy for $$ \mathcal{O}(10) $$ O 10 MeV DM mass with one electron threshold.

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The local high-velocity tail and the Galactic escape speed

Cited by 119 publications

References 85 publications

The mass of our Galaxy from satellite proper motions in the Gaia era

The mass of our Galaxy from satellite proper motions in the Gaia era

The milky way total mass profile as inferred from Gaia DR2

Dark matter substructures affect dark matter-electron scattering in xenon-based direct detection experiments

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