Related papers: The shock-induced star formation sequence resultin…

We review Foyle et al. (2011) previous results, by applying a Fourier intensity phases method to a nine object sample of galaxies. It was found that two of the objects (NGC 628 and NGC 5194), with strong two-arm patterns, present positive…

We investigate the relationship between spiral arms and star formation in the grand-design spirals NGC 5194 and NGC 628 and in the flocculent spiral NGC 6946. Filtered maps of near-IR (3.6 micron) emission allow us to identify "arm regions"…

We present a revised method for simultaneous determination of the pattern speed and star formation timescale of spiral galaxies, its application, and results for CO and Ha images of nearby spiral galaxies. Out of 13 galaxies, we were able…

Star formation induced by a spiral shock wave, which in turn is generated by a spiral density wave, produces an azimuthal age gradient across the spiral arm, which has opposite signs on either side of the corotational resonance. An analysis…

We test whether the spiral patterns apparent in many large disk galaxies should be thought of as dynamical features that are stationary in a co-rotating frame for > t_{dyn}, as implied by the density wave approach for explaining spiral…

We combine JWST observations with ALMA CO and VLT-MUSE H$\alpha$ data to examine off-spiral arm star formation in the face-on, grand-design spiral galaxy NGC 628. We focus on the northern spiral arm, around a galactocentric radius of 3-4…

Shock induced star formation in a stellar density wave scenario produces an azimuthal gradient of ages across the spiral arms which has opposite signs on either side of the corotation resonance (CR). We present a method based on the Fourier…

We present VLA H I and 6 cm radio continuum observations of the spiral NGC 3145 and H I observations of its two companions, NGC 3143 and PGC 029578. In optical images NGC 3145 has stellar arms that appear to cross, forming "X"-features. Our…

Deep JHK-Brg photometry of the southern arm of the grand-design spiral galaxy NGC 2997 was obtained by ISAAC/VLT. All sources in the field brighter than K=19 mag were located. Color-color diagrams were used to identify young stellar…

We estimate a characteristic timescale for star formation in the spiral arms of disk galaxies, going from atomic hydrogen (HI) to dust-enshrouded massive stars. Drawing on high-resolution HI data from The HI Nearby Galaxy Survey and…

We present new J=1-0 12-CO observations along the northern spiral arm of the grand-design spiral galaxy M100 (NGC 4321), and study the distribution of molecular hydrogen as derived from these observations, comparing the new data with a set…

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…

We have measured the positions of large numbers of H II regions in four nearly face-on, late-type, spiral galaxies: NGC 628 (M 74), NGC 1232, NGC 3184 and NGC 5194 (M 51). Fitting log-periodic spiral models to segments of each arm yields…

We combine James Webb Space Telescope images of the nearby galaxy NGC 5194 in the hydrogen recombination line Pa-alpha (lambda=1.8756 micron) from the Cycle 1 program JWST-FEAST with 21 micron dust continuum images from the Cycle 2 Treasury…

Relations between star formation rates along the spiral arms and the velocities of gas inflow into the arms in grand-design galaxy NGC 628 were studied. We found that the radial distribution of average star formation rate in individual star…

Gaia recently revealed a two-armed spiral pattern in the vertical phase-space distribution of the inner Galactic disk (guiding radius $R_\textrm{g} \sim 6.2$ kpc), indicating that some non-adiabatic perturbation symmetric about the…

Star formation (SF) takes place in unusual places such as way out in the intergalactic medium out of material expelled from parent galaxies. We wish to answer whether SF proceeds in this specific environment in a similar way than in…

We report on high-resolution interferometer observations of the 12CO(J=1-0) emission in the central 5 kpc region of the Seyfert 2 galaxy NGC 4501. The observations were made using the Nobeyama Millimeter Array during a long-term CO line…

Context. There is a contradiction between the characteristic spacings in observed regular chains of star-forming regions in the spiral arms of galaxies, ~500 pc, and the estimates of the wavelength of gravitational instability in them, >1…

We have searched for corotations (CR) in three Southern grand design spiral galaxies: NGC 1365, NGC 1566 and NGC 2997. We have also introduced a method of quantifying errors in the phase diagram used to detect CR. We established the m=2…