Dark matter in the Milky Way II. The HI gas distribution as a tracer of the gravitational potential

By P. Kalberla, L. Dedes, J. Kerp, U. Haud. 2007

163 citations recorded by the source corpus.

Context. Gas within a galaxy is forced to establish pressure balance against gravitational forces. The shape of an unperturbed gaseous disk can be used to constrain dark matter models. Aims. We derive the 3D H i volume density distribution for the Milky Way out to a galactocentric radius of 40 kpc and a height of 20 kpc to constrain the Galactic mass distribution. Methods. We used the Leiden/Argentine/Bonn all sky 21-cm line survey. The transformation from brightness temperatures to densities depends on the rotation curve. We explored several models, reflecting different dark matter distributions. Each of these models was set up to solve the combined Poisson-Boltzmann equation in a self-consistent way and optimized to reproduce the observed flaring. Results. Besides a massive extended halo of M ∼ 1.8 × 10 12 M� , we find a self-gravitating dark matter disk with M = 2t o 3 × 10 11 M� , including a dark matter ring at 13 < R < 18.5 kpc with M = 2. 2t o 2.8 × 10 10 M� . The existence of the ring was previously postulated from EGRET data and coincides with a giant stellar structure that surrounds the Galaxy. The resulting Milky Way rotation curve is flat up to R ∼ 27 kpc and slowly decreases outwards. The H i gas layer is strongly flaring. The HWHM scale height is 60 pc at R = 4 kpc and increases to ∼2700 pc at R = 40 kpc. Spiral arms cause a noticeable imprint on the gravitational field, at least out to R = 30 kpc. Conclusions. Our mass model supports previous proposals that the giant stellar ring structure is due to a merging dwarf galaxy. The fact that the majority of the dark matter in the Milky Way for R < 40 kpc can be successfully modeled by a self-gravitating isothermal disk raises the question of whether this massive disk may have been caused by similar merger events in the past. The substructure in the Galactic dark matter disk suggests a dissipative nature for the dark matter disk.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/d8ac025d713643add1cc1aa00b532e28122a0868

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

Citations in the corpus

A NEW ELECTRON-DENSITY MODEL FOR ESTIMATION OF PULSAR AND FRB DISTANCES (2016, background): “…of 4–5 kpc. Analyses of the z-distribution of tracers of high-density gas in the Galactic disk and spiral arms such as neutral hydrogen (H I; e.g., Kalberla et al. 2007) and molecular gas (e.g., Nakanishi & Sofue 2006) give scale heights in the range 50–70 pc at Galactocentric radii of 4–6 kpc,…”
DOES THE STELLAR DISTRIBUTION FLARE? A COMPARISON OF STELLAR SCALE HEIGHTS WITH LAB H i DATA (2014, methodology): “In the following we will consider more recent H i Leiden/Argentine/Bonn (LAB) survey data (Kalberla et al. 2005) and flaring compilations from Kalberla et al. (2007), Kalberla & Dedes (2008), and Kalberla & Kerp (2009).”
Global properties of the H I distribution in the outer Milky Way - Planar and extra-planar gas (2008, methodology): “Surface densities and mid-plane volume densities are a ﬀ ected by spiral structure, but di ﬀ erences between north and south need to be explained by an asymmetric disk (Levine et al. 2006a,b; Kalberla et al. 2007).”
The local dark matter density (2014, methodology): “To obtain a distance from this, we must model the gas assuming both hydrostatic equilibrium and some background potential for the Milky Way (Kalberla, 2003; Kalberla et al., 2007).”
Determination of the Local Dark Matter Density in our Galaxy (2009, background): “onotonical decreasing RC for the smooth halo proﬁles do not describe the data well. The change of slope may be related to a ringlike DM substructure , as indicated by the structure in the gas ﬂaring (Kalberla et al. 2007) and by the structure in t he diﬀuse gamma radiation (de Boer et al. 2005). Suc”
Cepheid variables in the flared outer disk of our galaxy (2014, methodology): “ of A V = 0.22 mag, A I = 0.13 mag, A J = 0.06 mag and A K = 0.02 mag for the LMC direction, we then have the distance modulus μ 0 for a Cepheid with a pulsation period P: µ 0+A V= V+2.762logP+1.190, (1) µ 0+A I=I+2.959logP+1.751 (2) and µ 0+A J=J+3.138logP+2.109, (3) µ 0+A K=K S+3.284logP+2.383. (4”
The Galaxy in Context: Structural, Kinematic, and Integrated Properties (2016, background): “Kalberla et al. (2007) found evidence from HI data for a ring-like distribution of dark matter around r ∼ 15 kpc.”
Magnetic fields and spiral arms in the galaxy M51 (2010, background): “A field reversal between the regular fields in the disc and the inner halo has also been suggested in the Milky Way (Sun et al. 2008), perhaps similar to the northern half of M51 (Fig.”
Gaseous Galaxy Halos (2012, background): “The Milky Way has a total mass of ∼ 2× 1012 M (Reid et al., 2009; Kalberla et al., 2007), and ideally we would discuss only galaxies of this mass for comparison.”
Thin, thick and dark discs in ΛCDM (2008, background): “While the half-mass scalelength and height of our dark disc match well those of Kalberla et al. (2007), our disc appears significantly less massive.”
Star Formation in the Milky Way and Nearby Galaxies (2012, methodology): “Based on a model including dark matter (Kalberla & Kerp 2009; Kalberla et al. 2007; Kalberla & Dedes 2008), the MW mass within 60 kpc of the center is M(tot) = 4.6× 1011 M⊙, with M(baryon) = 9.5× 10 10 M⊙.”
Galactic Searches for Dark Matter (2012, background): “ can reproduce the above observed \ aring" of the HI disk. Several studies have shown that it is dicult to reproduce the aring within the context of spherical halo models (Narayan et al., 2005; Kalberla et al., 2007). Banerjee and Jog (2011) nd that the aring can be reproduced by a prolate dark”
Painting a portrait of the Galactic disc with its stellar clusters (2020, background): “The warping of the Galactic plane is particularly visible in the HI gas distribution (Burke 1957; Kerr 1957; Westerhout 1957; Levine et al. 2006; Kalberla et al. 2007) and is now known to be a common feature in disc galaxies (e.g. Sancisi 1976; A1, page 13 of 17 Briggs 1990; Sánchez-Saavedra et al.…”
KINEMATICAL AND CHEMICAL VERTICAL STRUCTURE OF THE GALACTIC THICK DISK. II. A LACK OF DARK MATTER IN THE SOLAR NEIGHBORHOOD, (2012, methodology): “Among the possibilities offered by the literature, the solution closest to the expectations of a DM halo model is obtained assuming a rotation curve increasing its steepness from ∂V∂R ∣ ∣ ∣Z=0= 0 to ∂V ∂R ∣ ∣ ∣Z=4kpc≈ 7 km s−1 kpc−1, as modeled by Kalberla et al. (2007) for the Galactic gas.”
A-type stars in the Canada–France Imaging Survey – II. Tracing the height of the disc at large distances with Blue Stragglers (2018, background): “The first evidence of the flaring of the Galactic disc was discovered by Lozinskaya and Kardashev (1963), who observed that the scale height of the atomic H i gas distribution of the disc increases with Galactic radius, reaching a scale height of 2.7 kpc at ∼40 kpc (Kalberla et al. 2007).”
The H i Distribution of the Milky Way (2009, methodology): “These results are consistent with a local halo scale height of hz ∼ 4 kpc for the halo Hi. Disregarding the lagging halo rotation may lead to serious biases in the derived volume density distribution for the disk-halo interface (Kalberla et al. 2007, their figures 10–13).”