Constraining the vertical structure of the Milky Way rotation by microlensing in a finite-width global disk model

Abstract

We model the vertical structure of mass distribution of the Milky Way galaxy in the framework of a finite-width global disk model. Assuming only the Galactic rotation curve, we tested the predictions of the model inside the solar orbit for two measurable processes that are unrelated to each other: the gravitational microlensing that allows one to fix the disk width-scale by the best fit to measurements, and the vertical gradient of rotation modeled in the quasi-circular orbits approximation. The former is sensitive to the gravitating mass in compact objects, the latter to all kinds of gravitating matter. The analysis points to a small width-scale of the considered disks and an at-most insignificant contribution of non-baryonic dark matter in the solar circle. The predicted high vertical gradient values in the rotation are consistent with the gradient measurements.

Motion of halo tracer objects in the gravitational potential of a low-mass model of the Galaxy

“…Interestingly, the lower bound coincides with the sum of the dynamical mass ≈ 1.5×10 11 M inferred from the rotation curve in disk model (Ja locha et al 2014;Sikora et al 2012) and the mass (1.2−6.1)×10 10 M of the hot gaseous halo surrounding Milky Way (Gupta et al 2012). The gravitational potential of these components can be interpreted as a perturbation of a point mass potential.…”

“…with σ(ρ) being the column mass density of a finite-width disk found by recursions from the Galactic rotation curve in Jałocha et al (2014). Here, k = 4 ρρ (ρ+ρ) 2 +ζ 2 and K is the elliptic integral of the first kind defined in Gradshtein et al (2007).…”

“…with σ(ρ) being the column mass density of a finite-width disk found by recursions from the Galactic rotation curve in (Ja locha et al 2014). Here, k = the inner disk ρ < 20 kpc: M 20 = 1.49 × 10 11 M , while M 30 = 1.51×10 11 M .…”

Progress in the Global Modeling of the Galactic Magnetic Field

“…For the Galactic rotation curve we used a fit to the high-mass starforming regions with parallax measurements from [8] (see top right panel of Fig. 3) and for the vertical velocity gradient we assume a constant value inspired by simulations [18] and constrain it within two sigma of the value of (22±6) (km/s)/kpc as observed close to the Galactic midplane [19]. The resulting sky maps of RM, Q and U of the un-twisted model and the evolved model (t = 70 Myr) are shown in the left and middle panel of Fig.…”

Research on the Galaxy Rotation Model based on 21 cm Hydrogen Spectrum

“…After J. Oort reported the indications by his research of the stars in the solar neighborhood, a great deal of models about the Galaxy rotation with their own rationality in that era appeared [33]. But with the author's persuasive 21 cm hydrogen spectrum discovered, some of the models could be obsoleted because they have big differences with the gLon data.…”