Related papers: Uncovering Spiral Structure in Flocculent Galaxies
Emission profiles of the Galactic plane in K and at $240\micron$ are presented, and features associated with the tangents of the spiral arms are identified. In the K band, which traces stellar emission and suffers little from absorbtion,…
We have imaged a sample of 45 face-on spiral galaxies in the K-band, to determine the morphology of the old stellar population, which dominates the mass in the disk. The K-band images of the spiral galaxies have been used to calculate…
Little is known about the portion of the Milky Way lying beyond the Galactic center at distances of more than 9 kilo-parsec from the Sun. These regions are opaque at optical wavelengths due to absorption by interstellar dust, and distances…
High-resolution far-infrared (FIR) observation of submillimeter galaxies (SMGs) is an effective approach to study the formation of sub-structures in the early epoch of massive galaxies. We present the 870$\mu$m continuum images resolved…
We report the discovery of trailing grand-design nuclear spiral structure in the spiral galaxy NGC 5248. Two tightly-wound red spiral arms, with widths less than 1 arcsec (~75 pc), emanate at 1 arcsec outside the quiescent nucleus of the…
Fourier transform power spectra of azimuthal scans of the optical structure of M33 are evaluated for B, V, and R passbands and fit to fractal models of continuum emission with superposed star formation. Power spectra are also determined for…
We present data for a sample of 45 spiral galaxies over a range of Hubble types, imaged in the near-IR J and K bands. Parameters are calculated describing the bulge, disk and bar K-band light distributions, and we look for correlations…
We present a map of the spiral structure of the Galaxy, as traced by molecular CS emission associated with IRAS sources which are believed to be compact HII regions. The CS line velocities are used to determine the kinematic distances of…
We consider the possible pattern of the overall spiral structure of the Galaxy, using data on the distribution of neutral (atomic), molecular, and ionized hydrogen, on the base of the hypothesis of the spiral structure being symmetric, i.e.…
We present the minor-axis kinematics of ionized gas and stars for a sample of 5 spiral galaxies, which are characterized by either a zero or a shallow gas velocity gradient along their major axis. The asymmetric velocity profiles observed…
Two dimensional Fourier spectra of near-infrared images of galaxies provide a powerful diagnostic tool for the detection of spiral arm modulation in stellar disks. Spiral arm modulation may be understood in terms of interference patterns of…
Spiral arms shown by different components may not be spatially coincident, which can constrain formation mechanisms of spiral structure in a galaxy. We reassess the spiral arm tangency directions in the Milky Way through identifying the…
We describe the structure and composition of six major stellar streams in a population of 20 574 local stars in the New Hipparcos Reduction with known radial velocities. We find that, once fast moving stars are excluded, almost all stars…
Deep HI observations of the outer parts of disc galaxies demonstrate the frequent presence of extended, well-developed spiral arms far beyond the optical radius. To understand the nature and the origin of such outer spiral structure, we…
Spiral density wave theory attempts to describe the spiral pattern in spiral galaxies in terms of a long-lived wave structure with a constant pattern speed in order to avoid the winding dilemma. The pattern is consequently a rigidly…
High resolution N-body simulations using different codes and initial condition techniques reveal two different behaviours for the rotation frequency of transient spiral arms like structures. Whereas unbarred disks present spiral arms nearly…
We analyze formation of grand-design two-arm spiral structure in the nuclear regions of disk galaxies. Such morphology has been recently detected in a number of objects using high-resolution near-infrared observations. Motivated by the…
Spiral galaxies have distinct internal structures including a stellar bulge, disk and spiral arms. It is unknown when in cosmic history these structures formed. We analyze observations of BRI 1335-0417, an intensely star-forming galaxy in…
We investigate the morphology and kinematics of the Galactic spiral structure based on a new sample of O- and early B-type stars. We select 6,858 highly confident OB star candidates from the combined data of the VST Photometric H$\alpha$…
The density-wave theory of spiral structure proposes that star formation occurs in or near a spiral-shaped region of higher density that rotates rigidly within the galactic disk at a fixed pattern speed. In most interpretations of this…