The mass of the Milky Way out to 100 kpc using halo stars

Deason, Alis J.; Erkal, Denis; Belokurov, Vasily; Fattahi, Azadeh; Gómez, Facundo A.; Grand, Robert J. J.; Pakmor, Rüdiger; Xue, Xiang-Xiang; Liu, Chao; Yang, Chengqun; Zhang, Lan; Zhao, Gang

doi:10.1093/mnras/staa3984

Cited by 79 publications

(77 citation statements)

References 82 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although we do not see any strong evidence for such features in this sample (see Fig. 3 and associated discussion in Deason et al 2021), larger upcoming spectroscopic surveys such as WEAVE, DESI, and 4MOST will be able to better explore this possibility.…”

Section: Stellar Halo Substructurementioning

confidence: 60%

See 1 more Smart Citation

Detection of the LMC-induced sloshing of the Galactic halo

Erkal

Deason

Belokurov

et al. 2021

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

A wealth of recent studies have shown that the LMC is likely massive, with a halo mass >1011M⊙. One consequence of having such a nearby and massive neighbour is that the inner Milky Way is expected to be accelerated with respect to our Galaxy’s outskirts (beyond ∼30 kpc). In this work we compile a sample of ∼500 stars with radial velocities in the distant stellar halo, rGC > 50 kpc, to test this hypothesis. These stars span a large fraction of the sky and thus give a global view of the stellar halo. We find that stars in the Southern hemisphere are on average blueshifted, while stars in the North are redshifted, consistent with the expected, mostly downwards acceleration of the inner halo due to the LMC. We compare these results with simulations and find the signal is consistent with the infall of a 1.5 × 1011M⊙ LMC. We cross-match our stellar sample with Gaia DR2 and find that the mean proper motions are not yet precise enough to discern the LMC’s effect. Our results show that the Milky Way is significantly out of equilibrium and that the LMC has a substantial effect on our Galaxy.

show abstract

Section: Stellar Halo Substructurementioning

confidence: 60%

“…As explained in Erkal, Belokurov & Parkin (2020), if this disequilibrium is not accounted for, estimates of the Milky Way mass will be biased in the outer halo. We perform this correction and measure the Milky Way mass out to 100 kpc in a companion work (Deason et al 2021).…”

Section: Discussionmentioning

confidence: 99%

Detection of the LMC-induced sloshing of the Galactic halo

Erkal

Deason

Belokurov

et al. 2021

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

show abstract

“…Of these, the closest to our estimate is that of GC19, which has a virial mass of M 200 = 1.2 × 10 12 M . Interestingly, this is also the mass favoured by the recent analysis of stellar halo kinematics by Deason et al (2020).…”

Section: T H E L M C a N D T H E E S C A P E V E L O C I T Y O F T H E M Wmentioning

confidence: 77%

Magellanic satellites in ΛCDM cosmological hydrodynamical simulations of the Local Group

Santos-Santos

Fattahi

Sales

et al. 2021

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

We use the APOSTLE ΛCDM cosmological hydrodynamical simulations of the Local Group to study the recent accretion of massive satellites into the halo of Milky Way (MW)-sized galaxies. These systems are selected to be close analogues to the Large Magellanic Cloud (LMC), the most massive satellite of the MW. The simulations allow us to address, in a cosmological context, the impact of the Clouds on the MW, including the contribution of Magellanic satellites to the MW satellite population, and the constraints placed on the Galactic potential by the motion of the LMC. We show that LMC-like satellites are twice more common around Local Group-like primaries than around isolated halos of similar mass; these satellites come from large turnaround radii and are on highly eccentric orbits whose velocities at first pericentre are comparable with the primary’s escape velocity. This implies $V_{\rm esc}^{\rm MW} (50$ kpc) ∼ 365 km/s, a strong constraint on Galactic potential models. LMC analogues contribute about 2 satellites with M* > 105 M⊙, having thus only a mild impact on the luminous satellite population of their hosts. At first pericentre, LMC-associated satellites are close to the LMC in position and velocity, and are distributed along the LMC’s orbital plane. Their orbital angular momenta roughly align with the LMC’s, but, interestingly, they may appear to “counter-rotate” the MW in some cases. These criteria refine earlier estimates of the LMC association of MW satellites: only the SMC, Hydrus1, Car3, Hor1, Tuc4, Ret2 and Phoenix2 are compatible with all criteria. Carina, Grus2, Hor2 and Fornax are less probable associates given their large LMC relative velocity.

show abstract

“…Using the Boylan-Kolchin et al (2013) phase space plot, Hammer et al (2020) showed that Gaia DR2 orbits might indicate a passage more recent than 4 Gyr ago for many dSphs, assuming a total mass of 8.66 × 10 11 M for the MW (Eilers et al 2019). Because MW dSphs also have a peculiar planar alignment (Pawlowski et al 2014), Deason et al (2021 opted to use halo stars. After a thorough analysis of the possible recent accretions based on phase-space diagrams, they derived a total mass within 100 kpc of 6.07 × 10 11 M 2 , with which they associated systematics up to 1.2 × 10 11 M .…”

Section: Limitations Of This Study and Comparison With Other Workmentioning

confidence: 99%

Which Milky Way masses are consistent with the slightly declining 5–25 kpc rotation curve?

Yongjun

Hammer

Wang

et al. 2021

A&A

View full text Add to dashboard Cite

Context. Discoveries of extended rotation curves have suggested that spiral galaxy halos contain dark matter. This has led to many studies that estimated the total mass of the Galaxy, mostly using the Navarro, Frenk, and White (NFW) density profile. Aims. We determine the effect that the choice of the dark matter profile has on the predicted values of extrapolated total masses. Methods. We considered a recently reported Milky Way (MW) rotation curve, first because of its unprecedented accuracy, and second because the Galactic disk appears to be least affected by past major mergers that have fully reshaped the initial disk. Results. We find that the use of an NFW profile (or its generalized form, gNFW) to calculate the dark-matter contribution to the MW rotation curve generates apparently inconsistent results such as an increase in baryonic mass that leads to an increase in dark matter mass. Furthermore, we find that NFW and gNFW profiles narrow the total mass range, leading to a possible methodological bias particularly against low MW masses. Using the Einasto profile, which is better suited to represent cold dark matter halos, we finally found that the slightly decreasing rotation curve of the MW favors a total mass that can be as low as 2.6 × 1011 M⊙, disregarding any other dynamical tracers farther out in the MW. This is inconsistent with values higher than 18 × 1011 M⊙ for any type of cold dark matter halo profiles under the assumption that stars and gas do not affect the predicted dark matter distribution in the MW. Conclusions. This methodological paper encourages the use of the Einasto profile to characterize rotation curves with the aim of evaluating their total masses.

show abstract

The mass of the Milky Way out to 100 kpc using halo stars

Cited by 79 publications

References 82 publications

Detection of the LMC-induced sloshing of the Galactic halo

Detection of the LMC-induced sloshing of the Galactic halo

Magellanic satellites in ΛCDM cosmological hydrodynamical simulations of the Local Group

Which Milky Way masses are consistent with the slightly declining 5–25 kpc rotation curve?

Contact Info

Product

Resources

About