Galactic disk loses weight

Kinematics of Galactic Disk

The method of constructing of rotation curve for our galactic disk is developed. Simple physical model shows that the velocity of the Sun around the center of the Galaxy must be less than currently accepted IAU value 220 km/s. Independently obtained result for neutral hydrogen (λ = 21.1 cm) confirms the previous statement. The values of the Sun’s velocity is about 110 km/s. As a consequence, th...

Galactic Disk Warps

Galactic and Accretion Disk Dynamos

Dynamos in astrophysical disks are usually explained in terms of the standard alpha-omega mean field dynamo model where the local helicity generates a radial field component from an azimuthal field. The subsequent shearing of the radial field gives rise to exponentially growing dynamo modes. There are several problems with this model. The exponentiation time for the galactic dynamo is hard to c...

The Galactic disk: study of four low latitude Galactic Fields

We present deep V and I photometry of stellar field in four previously unstudied low latitude regions of the Galactic disk. All observed fields are located at the western side of the Galactic Center in the direction of the Coalsack-Carina region. They are chosen on the large scale surface photometry of the Milky Way (Hoffmann et al., 1998 and Kimeswenger et al., 1993) and corresponding term map...

Vertical distribution of Galactic disk stars ⋆

Nearly 400 Tycho-2 stars have been observed in a 720 square degree field in the direction of the North Galactic Pole with the high resolution echelle spectrograph ELODIE. Absolute magnitudes, effective temperatures, gravities and metallicities have been estimated, as well as distances and 3D velocities. Most of these stars are clump giants and span typical distances from 200 pc to 800 pc to the...