Results 51 to 60 of about 7,946 (225)

Stellar dynamics around transient co-rotating spiral arms

EPJ Web of Conferences, 2012
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.
Cropper M., Grand R.J.J., Kawata D.
doaj   +1 more source

Star formation in isolated AMIGA galaxies: dynamical influence of bars

, 2007
Star formation depends strongly both on the local environment of galaxies, and on the internal dynamics of the interstellar medium. To disentangle the two effects, we obtained, in the framework of the AMIGA project, Ha and Gunn r photometric data for ...
Athanassoula, Athanassoula, Berentzen, Berentzen, Block, Block, Bournaud, Bournaud, Buta, Combes, Combes, Combes, de Grijs, de Vaucouleurs, de Vaucouleurs, Elmegreen, Eskridge, Espada, F. Combes, Friedli, G. Bergond, García-Burillo, García-Burillo, Hameed, Helfer, James, Jogee, Karachentseva, Knapen, Knapen, L. Verdes-Montenegro, Laurikainen, Laurikainen, Leon, Lisenfeld, Martin, Pfenniger, Quillen, Reynaud, S. Leon, S. Verley, Seigar, Shen, Sheth, Sulentic, Varela, Verdes-Montenegro, Verley, Verley   +48 more
core   +1 more source

Star Formation History in Barred Spiral Galaxies. AGN Feedback [PDF]

, 2017
We present a numerical study of the impact of AGN accretion and feedback on the star formation history of barred disc galaxies. Our goal is to determine whether the effect of feedback is positive (enhanced star formation) or negative (quenched star ...
Ellison, Sara L., Kawata, Daisuke, Martel, Hugo, Robichaud, Fidèle, Williamson, David   +4 more
core   +2 more sources

A hitchhiker's guide to modern, practical cyanobacterial taxonomy

Journal of Phycology, EarlyView.
Abstract There has been an explosion of new Cyanobacterial taxa described within the last two decades. Cyanobacteria exhibit incredible ecological versatility and morphological variability, and thousands of species have already been described using “traditional” approaches (e.g., morphological features).
Petr Dvořák, Svatopluk Skoupý, Aleksandar Stanojković, Jeffrey R. Johansen, Chelsea Villanueva, Patrick Jung, Laura Briegel‐Williams, H. Dail Laughinghouse IV, Forrest W. Lefler, David E. Berthold, Jan Kaštovský, Anne C. Hurley, Dale A. Casamatta   +12 more
wiley   +1 more source

On the Role of Noncircular Motions in MaNGA Galaxies. I. Global Properties

The Astrophysical Journal
Noncircular (NC) motions represent the imprints of nonaxisymmetric structures in galaxies, providing opportunities to study the physical properties of gas departing from circular rotation.
Carlos López-Cobá, Lihwai Lin, Justus Neumann, Matthew A. Bershady   +3 more
doaj   +1 more source

Star formation efficiency in the Barred Spiral Galaxy NGC 4303 [PDF]

, 2010
We present new $^{12}$CO(J=1-0) observations of the barred galaxy NGC 4303 using the Nobeyama 45m telescope (NRO45) and the Combined Array for Research in Millimeter-wave Astronomy (CARMA). The H$\alpha$ images of barred spiral galaxies often show active
Alonso-Herrero, Arimoto, Bigiel, Calzetti, Colina, Corder, de Vaucouleurs, Egusa, Egusa, Gezari, Gezari, Helfer, Jin Koda, Kennicutt, Koda, Koda, Koopmann, Kuno, Kurono, Laine, Leroy, Rieko Momose, Sachiko K. Okumura, Sakamoto, Sakamoto, Sault, Sawada, Schinnerer, Scoville, Sheth, Sheth, Strong, Tamburro, Tschöke, Tsuyoshi Sawada, Wong   +35 more
core   +2 more sources

The stellar dynamics of spiral arms in barred spiral galaxies [PDF]

Monthly Notices of the Royal Astronomical Society: Letters, 2006
Abstract A dynamical mechanism is proposed that explains the spiral structure observed frequently as a continuation of the bars in barred spiral galaxies. It is argued that the part of the spirals attached to the bar is due to chaotic orbits. These are chaotic orbits that exhibit for long time intervals a 4:1-resonance orbital behaviour.
openaire   +1 more source

Noble gases and nitrogen in material from asteroid Bennu

Meteoritics &Planetary Science, EarlyView.
Abstract We report the elemental and isotopic abundances of all stable noble gases (helium, neon, argon, krypton, and xenon) in eight particles from asteroid Bennu returned by NASA's OSIRIS‐REx mission. We also report nitrogen abundances and isotopic ratios that were analyzed alongside neon and argon in four additional Bennu particles.
B. Marty, L. Zimmermann, E. Füri, D. V. Bekaert, J. J. Barnes, A. N. Nguyen, H. C. Connolly, D. S. Lauretta   +7 more
wiley   +1 more source

SDSS-IV MaNGA: Physical Origins of Double-peaked Narrow Emission-line Spaxels in Barred Galaxies

The Astrophysical Journal
The physical origins of double-peaked narrow emission-line spaxels (DPSs) in barred galaxies are explored through the analysis of a sample of 72 barred double-peaked emission-line galaxies (DPGs) extracted from the MaNGA data set.
Jiajie Qiu, Shiyin Shen, Ruixiang Chang, Qianwen Zhao, Qi Zeng   +4 more
doaj   +1 more source

The Stochastic‐Dissipative Störmer Problem‐Trajectories and Radiation Patterns

Annalen der Physik, Volume 537, Issue 12, December 2025.
We consider charged particle motion and radiation in a dipole magnetic field, in the presence of friction and of stochastic forces. The numerical solutions of the Langevin equation reveal how these forces modify the complex dynamics of particles, and they offer some new insights into the nonlinear processes relevant to planetary radiation belts ...
Tiberiu Harko, Gabriela Raluca Mocanu
wiley   +1 more source