We present new spectroscopic observations of the inner circumgalactic medium (CGM) of NGC 891 taken with the Mid-Infrared Imager/Medium Resolution Spectroscopy instrument on board JWST, in four positions: two near the bulge and two at galactocentric radii (r) of ∼1.5, 4.7 kpc. Each pair of pointings has one position along the minor axis (h) at ∼0.5 kpc and one at ∼1 kpc away from the mid-plane. We analysed 1D spectra and 3D cubes using the dust emission model PAHFIT to extract properties of typical mid-IR features. These spectra reveal that the earlier reported mid-IR emission out to 4 kpc is dominated by the emission of polycyclic aromatic hydrocarbons (PAHs), and not hot dust continuum, thus providing direct evidence of the survival of PAHs in the inner CGM of NGC 891. Comparing PAH band ratios with other environments (Orion, M51), it is obvious that the 11.2 μm PAH feature – and not the usual 7.7 μm – dominates in NGC 891, which seems to imply the presence of more neutral, large PAHs in the CGM. Overall, PAH-to-continuum ratios show little variations with scale-height and radius in NGC 891, which suggests little PAH processing. However, we do see a decrease in the PAH feature strengths with the [Ne III]/[Ne II] ratio, which points to elevated dust processing with increased radiation field hardness. We also confirm a tight correlation between H2 and PAH features, which suggests that the two tracers must be co-spatial, and hence implies that PAH emission predominantly arises from cool dense parts of cloudlets entrained in galactic outflows. Finally, we report the clear detection of a previously unidentified PAH feature at 16.72 μm.

We present a new two-dimensional (2D) map of total Galactic extinction, AV, across the entire dust half-layer from the Sun to extragalactic space for Galactic latitudes ∣b∣ > 13°, as well as a three-dimensional (3D) map of AV within 2 kpc of the Sun. These maps are based on AV and distance estimates derived from a data set, which utilizes Gaia Data Release 3 parallaxes and multi-band photometry for nearly 100 million dwarf stars. We apply our own corrections to account for significant systematics in this data set. Our 2D map achieves an angular resolution of 6

1, while the 3D map offers a transverse resolution of 3.56 pc—corresponding to variable angular resolution depending on distance—and a radial resolution of 50 pc. In constructing these maps, we pay particular attention to the solar neighborhood (within 200 pc) and to high Galactic latitudes. The 3D map predicts AV from the Sun to any extended object within the Galactic dust layer with an accuracy of σ(AV) = 0.1 mag. The 2D map provides AV estimates for the entire dust half-layer up to extragalactic distances with an accuracy of σ(AV) = 0.07 mag. We provide AV estimates from our maps for various classes of extended celestial objects with angular size primarily in the range of 2′–40′, including 19,809 galaxies and quasars, 170 Galactic globular clusters, 458 open clusters, and several hundred molecular clouds from two lists. We also present extinction values for 8293 Type Ia supernovae. Comparison of our extinction estimates with those from previous maps and literature sources reveals systematic differences, indicating large-scale spatial variations in the extinction law and suggesting that earlier 2D reddening maps based on infrared dust emission tend to underestimate low extinction values.

Galaxies with polar structures (of which polar-ring galaxies (PRGs) are a prominent subclass) contain components that are kinematically decoupled and highly inclined relative to the major axis of the host galaxy. Modern deep optical surveys provide a powerful means of detecting low surface brightness (LSB) features around galaxies, which offers critical insights into the formation and evolution of galaxies with polar structures. UGC 10043 is an edge-on galaxy that is notable for its prominent bulge, which extends orthogonally to the disk plane. In addition, the galaxy displays a well-defined integral-shaped disk warp and multiple dust features crossing the bulge along the minor galaxy axis. We present new deep optical photometry of UGC 10043 down to μ_g = 29.5 mag arcsec⁻² and perform a detailed analysis of its LSB and polar structures. The observations reveal a stellar stream aligned along the polar axis, alongside other signatures of tidal interaction, including a flat, tilted LSB envelope that extends toward the neighboring galaxy MCG +04-37-035, with which UGC 10043 is connected by an HI bridge. Our results suggest that the polar component of UGC 10043 comprises an older, triaxial polar bulge and a younger, forming polar structure that likely originates from the ongoing disruption of a dwarf satellite galaxy. It also simultaneously participates in active interaction with MCG +04-37-035.

Context. Approximately half of all disk galaxies exhibit appreciable warps in both their stellar and H I disks. The typical warp amplitude is small (a few degrees) and only becomes noticeable at the periphery of the galaxy disk. As a result, warps remain a relatively poorly studied phenomenon.

Aims. In this study, we investigate a large sample of distant edge-on galaxies (approximately 1000 objects) in order to examine the frequency and characteristics of stellar disk warps up to a redshift of z ∼ 2.

Methods. For the selected galaxies, we used Hubble Space Telescope data from the Cosmic Evolution Survey field and JWST observations from the Cosmic Dawn Center Archive. We measured the properties of disk warps and investigated their evolution as a function of redshift.

Results. Our results indicate a potential evolution in the observed frequency of strong S-shaped warps (with an amplitude greater than 4°) in stellar disks as a function of redshift. At z ≈ 2, the frequency of strong warps reaches approximately 50%, while at z ≈ 0, this fraction decreases to around 10–15%. We attribute the observed evolution in the occurrence of strong warps to the changing frequency of galaxy interactions and mergers. If galaxy interactions represent one of the primary mechanisms responsible for the formation of warps, then the prevalence of vertical disk deformations should increase in tandem with the rising interaction and merger rate.

We analyze three nearby spiral galaxies—NGC 1097, NGC 1566, and NGC 3627—using images from the DustPedia database in seven infrared bands (3.6, 8, 24, 70, 100, 160, and 250 μm). For each image, we perform photometric decomposition and construct a multi-component model, including a detailed representation of the spiral arms. Our results show that the light distribution is well described by an exponential disk and a Sérsic bulge when non-axisymmetric components are properly taken into account. We test the predictions of the stationary density wave theory using the derived models in bands, tracing both old stars and recent star formation. Our findings suggest that the spiral arms in all three galaxies are unlikely to originate from stationary density waves. Additionally, we perform spectral energy distribution (SED) modeling using the hierarchical Bayesian code HerBIE, fitting individual components to derive dust properties. We find that spiral arms contain a significant (>10%) fraction of cold dust, with an average temperature of approximately 18–20 K. The estimated fraction of polycyclic aromatic hydrocarbons (PAHs) declines significantly toward the galactic center but remains similar between the arm and interarm regions.

Spiral galaxies are ubiquitous in the local Universe. However, the properties of spiral arms in them are still not well studied, and there is even less information concerning spiral structure in distant galaxies. We aim to measure the most general parameters of spiral arms in remote galaxies and trace their changes with redshift. We perform photometric decomposition, including spiral arms, for 159 galaxies from the HST COSMOS and JWST CEERS and JADES surveys, which are imaged in optical and near-infrared rest-frame wavelengths. We confirm that, in our representative sample of spiral galaxies, the pitch angles increase, and the azimuthal lengths decrease with increasing redshift, implying that the spiral structure becomes more tightly wound over time. For the spiral-to-total luminosity ratio and the spiral width-to-disc scale length ratio, we find that band-shifting effects can be as significant as, or even stronger than, evolutionary effects. Additionally, we find that spiral structure becomes more asymmetric at higher redshifts.