Related papers: Do spiral arms enhance star formation efficiency?
We measure the pitch angle ($\varphi$) of spiral arms in a sample of 79 galaxies to perform a systematic study of the dependence of $\varphi$ on galaxy morphology, mass, and kinematics to investigate the physical origin of spiral arms. We…
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…
The process that leads to the formation of the bright star forming sites observed along prominent spiral arms remains elusive. We present results of a multi-wavelength study of a spiral arm segment in the nearby grand-design spiral galaxy…
Spiral arm structures seen in scattered light observations of protoplanetary disks can potentially serve as signposts of planetary companions. They can also lend unique insights into disk masses, which are critical in setting the mass…
Context: The Faraday rotation measure (RM) is often used to study the magnetic field strength and orientation within the ionized medium of the Milky Way. Observations indicate a RM in the spiral arms that exceeds the commonly assumed range.…
The line of sight through the Galactic Plane between longitudes l = 37.83 degr and l = 42.50 degr allows for the separation of Galactic Ring Survey molecular clouds into those that fall within the spiral arms and those located in the…
Tidal encounters are believed to be one of the key drivers of galactic spiral structure in the Universe. Such spirals are expected to produce different morphological and kinematic features compared to density wave and dynamic spiral arms.…
Star formation is enhanced in spiral arms because of a combination of orbit crowding, cloud collisions, and gravitational instabilities. The characteristic mass for the instability is 10^7 Msun in gas and 10^5 Msun in stars, and the…
It remains unclear how galactic environment affects star formation and stellar cluster properties. This is difficult to address in Milky Way-mass galaxy simulations because of limited resolution and less accurate feedback compared to…
Theoretical studies on the response of interstellar gas to a gravitational potential disc with a quasi-stationary spiral arm pattern suggest that the gas experiences a sudden compression due to standing shock waves at spiral arms. This…
The causes of spiral structure in galaxies remain uncertain. Leaving aside the grand bisymmetric spirals with their own well-known complications, here we consider the possibility that multi-armed spiral features originate from density…
This study investigated the relation between the surface density of star formation rate (SFR) ($\Sigma_{\mathrm{SFR}}$), stellar mass ($\Sigma_{M_{\ast}}$), and molecular gas mass ($\Sigma_{M_\mathrm{mol}}$) on nearly 1 kpc scales averaged…
We present the results from simulations of GMC formation in spiral galaxies. First we discuss cloud formation by cloud-cloud collisions, and gravitational instabilities, arguing that the former is prevalent at lower galactic surface…
We analyze radial and azimuthal variations of the phase balance between the molecular and atomic ISM in the Milky Way. In particular, the azimuthal variations -- between spiral arm and interarm regions -- are analyzed without any explicit…
Tidal interactions between disc galaxies and low mass companions are an established method for generating galactic spiral features. In this work we present a study of the structure and dynamics of spiral arms driven in interactions between…
Spiral arms play a central role in disc galaxies, but their dynamical nature remains a long-standing open question. Azimuthal offsets between molecular gas and star formation are expected if gas crosses spiral arms, as predicted by…
We present ongoing hydrodynamic and MHD simulations of molecular cloud formation in spiral galaxies. The hydrodynamic results show the formation of molecular gas clouds where spiral shocks compress atomic gas to high densities. The spiral…
The nature of galactic spiral arms in disc galaxies remains elusive. Regardless of the spiral model, arms are expected to play a role in sculpting the star-forming interstellar medium. As such, different arm models may result in differences…
Identifying the structure of our Galaxy has always been fraught with difficulties, and while modern surveys continue to make progress building a map of the Milky Way, there is still much to understand. The arm and bar features are important…
The majority of astrophysics involves the study of spiral galaxies, and stars and planets within them, but how spiral arms in galaxies form and evolve is still a fundamental problem. Major progress in this field was made primarily in the…