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This paper presents a comprehensive multiwavelength investigation of the intermediate-age open cluster NGC 1912. We identified 401 member stars for NGC 1912 using K-nearest neighbour and Gaussian Mixture Model machine learning techniques. The fundamental parameters determined for the cluster are metallicity (z) = 0.0141 |$\pm$| 0.0006, log(age) = 8.519 |$\pm$| 0.040, binary fraction (⁠|$b_{\text{frac}}$|⁠) = 0.445 |$\pm$| 0.035, visual extinction (⁠|$A_V$|⁠) = 0.864 |$\pm$| 0.033 mag, total-to-selective extinction ratio (⁠|$R_V$|⁠) = 3.007 |$\pm$| 0.096, distance = 1096 |$\pm$| 15 pc. The central density (⁠|$\rho _o$|⁠), core radius (⁠|$r_c$|⁠), tidal radius (⁠|$r_t$|⁠), and background density (⁠|$\rho _{\mathrm{bg}}$|⁠) for the cluster are obtained as 0.643 |$\pm$| 0.067 stars arcmin |$^{-2}$| , 7.743 |$\pm$| 0.784 arcmin, 84.633 |$\pm$| 7.188 arcmin, and 0.001 |$\pm$| 0.000 stars arcmin |$^{-2}$| , respectively. Dynamical mass segregation study revealed a concentration of some apparently massive stars towards the cluster centre. Polarimetric analysis of 90 stars in |$BVR_cI_c$| wavelength bands revealed that the observed polarization in NGC 1912 is not solely attributed to interstellar dust. The Galactic magnetic field is dominant in this region. Dust grain sizes within the intracluster region are found to be relatively smaller than that of the general ISM. The extinction map revealed the existence of a potential 'interstellar bubble' located close to the cluster region. Towards the periphery of the probable bubble region, which displays an ovoid-like geometry, 16 probable young stellar objects have been detected, suggesting the ongoing triggering of secondary star formation events in this region. [ABSTRACT FROM AUTHOR]

Dust in galaxies is an important tracer of galaxy properties and their evolution over time. The physical origin of the grain size distribution, the dust chemical composition, and, hence, the associated ultraviolet-to-optical extinctions in diverse galaxies remains elusive. To address this issue, we introduce a model for dust evolution in the RAMSES code for simulations of galaxies with a resolved multiphase interstellar medium. Dust is modelled as a fluid transported with the gas component, and is decomposed into two sizes, 5 nm and 0.1 μm, and two chemical compositions for carbonaceous and silicate grains. This dust model includes the growth of dust by accretion of elements from the gas phase and by the release of dust in stellar ejecta, the destruction by thermal sputtering, supernovae, and astration, and the exchange of dust mass between the two main populations of grain sizes by coagulation and shattering. Using a suite of isolated disc simulations with different masses and metallicities, the simulations can explore the role of these processes in shaping the key properties of dust in galaxies. The simulated Milky Way analogue reproduces the dust-to-metal mass ratio, depletion factors, size distribution and extinction curves of the Milky Way. Galaxies with lower metallicities reproduce the observed decrease in the dust-to-metal mass ratio with metallicity at around a few 0.1 Z⊙. This break in the dust-to-metal ratio corresponds to a galactic gas metallicity threshold that marks the transition from an ejecta-dominated to an accretion-dominated grain growth, and that is different for silicate and carbonaceous grains, with ≃0.1 Z⊙ and ≃0.5 Z⊙ respectively. This leads to more Magellanic Cloud-like extinction curves, i.e. with steeper slopes in the ultraviolet and a weaker bump feature at 2175 Å, in galaxies with lower masses and lower metallicities. Steeper slopes in these galaxies are caused by the combination of the higher efficiency of gas accretion by silicate relative to carbonaceous grains and by the low rates of coagulation that preserves the amount of small silicate grains. Weak bumps are due to the overall inefficient accretion growth of carbonaceous dust at low metallicity, whose growth is mostly supported by the release of large grains in SN ejecta. We also show that the formation of CO molecules is a key component to limit the ability of carbonaceous dust to grow, in particular in low-metallicity gas-rich galaxies. [ABSTRACT FROM AUTHOR]

Dust grains play a significant role in several astrophysical processes, including gas/dust dynamics, chemical reactions, and radiative transfer. Replenishment of small-grain populations is mainly governed by fragmentation during pair-wise collisions between grains. The wide spectrum of fragmentation outcomes, from complete disruption to erosion and/or mass transfer, can be modelled by the general non-linear fragmentation equation. Efficiently solving this equation is crucial for an accurate treatment of the dust fragmentation in numerical modelling. However, similar to dust coagulation, numerical errors in current fragmentation algorithms employed in astrophysics are dominated by the numerical overdiffusion problem – particularly in three-dimensional hydrodynamic simulations where the discrete resolution of the mass-density distribution tends to be highly limited. With this in mind, we have derived the first conservative form of the general non-linear fragmentation with a mass flux highlighting the mass transfer phenomenon. Then, to address cases of limited mass density resolution, we applied a high-order discontinuous Galerkin scheme to efficiently solve the conservative fragmentation equation with a reduced number of dust bins. An accuracy of |$0.1{\!-\!}1~{{\ \rm per\ cent}}$| is reached with 20 dust bins spanning a mass range of 9 orders of magnitude. [ABSTRACT FROM AUTHOR]

We present results of dust continuum and [C  ii ] |$\, 158\, {\rm \mu m}$| emission line observations of a remarkably UV luminous (M UV = −21.6) galaxy at z = 10.603: GN-z11. Using the Northern Extended Millimeter Array (NOEMA), observations have been carried out over multiple observing cycles. We achieved a high sensitivity resulting in a |$\lambda _{\rm rest}=160\, {\rm \mu m}$| continuum |$1\, \sigma$| sensitivity of |$13.0\, \rm {\mu Jy \, beam}^{ -1}$| and a [C  ii ] emission line |$1\, \sigma$| sensitivity of |$31\, \rm {mJy\, beam^{ -1}\, km \, s}^{ -1}$| using |$50\, \rm {km \, s}^{ -1}$| binning with a |$\sim 2\, {\rm arcsec}$| synthesized beam. Neither dust continuum nor [C  ii ] |$\, 158\, {\rm \mu m}$| line emission are detected at the expected frequency of ν[C ii ] |$= 163.791\, \rm {GHz}$| and the sky location of GN-z11. The upper limits show that GN-z11 is neither luminous in L IR nor L [C ii ], with a dust mass |$3\, \sigma$| limit of |${\rm log}\, (M_{\rm dust}/{\rm {\rm M}_{\odot }}) \, \lt\, 6.5-6.9$| and with a [C  ii ] based molecular gas mass |$3\, \sigma$| limit of log (M mol, [C ii ] |$/{\rm {\rm M}_{\odot }}) \, \lt \, 9.3$|⁠. Together with radiative transfer calculations, we also investigated the possible cause of the dust poor nature of the GN-z11 showed by the blue colour in the UV continuum of GN-z11 (βUV = −2.4), and found that ≳3 × deeper observations are crucial to study dust production at very high-redshift. Nevertheless, our observations show the crucial role of deep mm/submm observations of very high-redshift galaxies to constrain multiple phases in the interstellar medium. [ABSTRACT FROM AUTHOR]

We present a statistical and multiwavelength photometric studies of young open cluster IC 1590. We identified 91 cluster members using Gaia DR3 astrometry data using ensemble-based unsupervised machine learning techniques. From Gaia EDR3 data, we estimate the best-fitting parameters for IC 1590 using the Automated Stellar Cluster Analysis package (asteca) yielding the distance d ∼ 2.87 ± 0.02 kpc, age ∼ 3.54 ± 0.05 Myr, metallicity z ∼ 0.0212 ± 0.003, binarity value of ∼ 0.558, and extinction Av ∼ 1.252 ± 0.4 mag for an Rv value of ∼ 3.322 ± 0.23. We estimate the initial mass function slope of the cluster to be α = 1.081 ± 0.112 for single stars and α = 1.490 ± 0.051 for a binary fraction of ∼ 0.558 in the mass range 1  M⊙ ≤ m (M⊙) ≤ 100  M⊙. The G -band luminosity function slope is estimated to be ∼ 0.33 ± 0.09. We use (J − H) versus (H − Ks) colour–colour diagram to identify young stellar objects (YSOs). We found that all the identified YSOs have ages ≤ 2 Myr and masses ∼ 0.35 – 5.5  M⊙. We also fit the radial surface density profile. Using the galpy , we performed orbit analysis of the cluster. The extinction map for the cluster region has been generated using the PNICER technique, and it is almost similar to the dust structure obtained from the 500  μm dust continuum emissions map of Herschel SPIRE. We finally at the end discussed the star formation scenario in the cluster region. [ABSTRACT FROM AUTHOR]

Planetary nebulae (PNe) have long been known to consist of gas, molecules, and dust. The vast majority of the work in which properties of the dust of these objects are inferred were carried out through infrared observations. We use a technique that gives information about the dust, without nebular contamination, and regardless of its temperature. The primary objective is to present an atlas of images with the distribution of dust extinction in PNe. We obtained images in narrow-band filter centred on the nebular emission of the Balmer lines H α and H β to derive extinction images. By combining these images we have been able to achieve the distribution of dust in PNe. The atlas contains 29 PNe, representing the most comprehensive and extensive surveys of dust distribution in PNe. [ABSTRACT FROM AUTHOR]

Here, we present the cloud population extracted from M51, following the application of our new high-resolution dust extinction technique to the galaxy. With this technique, we are able to image the gas content of the entire disc of M51 down to 5 pc (0.14 arcsec), which allows us to perform a statistical characterization of well-resolved molecular cloud properties across different large-scale dynamical environments and with galactocentric distance. We find that cloud growth is promoted in regions in the galaxy where shear is minimized; i.e. clouds can grow into higher masses (and surface densities) inside the spiral arms and molecular ring. We do not detect any enhancement of high-mass star formation towards regions favourable to cloud growth, indicating that massive and/or dense clouds are not the sole ingredient for high-mass star formation. We find that in the spiral arms there is a significant decline of cloud surface densities with increasing galactocentric radius, whilst in the inter-arm regions they remain relatively constant. We also find that the surface density distribution for spiral arm clouds has two distinct behaviours in the inner and outer galaxy, with average cloud surface densities at larger galactocentric radii becoming similar to inter-arm clouds. We propose that the tidal interaction between M51 and its companion (NGC 5195) – which heavily affects the nature of the spiral structure – might be the main factor behind this. [ABSTRACT FROM AUTHOR]

Following from our recent work, we present results of a detailed analysis of a representative sample of nearby galaxies. The photometric parameters of the morphological components are obtained from bulge-disk decompositions, using GALFIT software. The previously obtained method and library of numerical corrections for dust, decomposition and projection effects, are used to correct the measured (observed) parameters to intrinsic values. Observed and intrinsic galaxy dust and star-formation related scaling relations are presented, to emphasize the scale of the biases introduced by these effects. To understand the extent to which star-formation is distributed in the young stellar disks of galaxies, star-formation connected relations which rely on measurements of scale-lengths and fluxes/luminosities of Hα images, are shown. The mean dust opacity, dust-to-stellar mass and dust-to-gas ratios of the sample, together with the main characteristics of the intrinsic relations are found to be consistent with values found in the literature. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) and fullerenes play a major role in the physics and chemistry of the interstellar medium (ISM). Based on a number of recent experimental and theoretical investigations we developed a model in which PAHs are subject to photo-dissociation (carbon and hydrogen loss) and hydrogenation. We take into account that dehydrogenated PAHs may fold into closed structures – fullerenes. Fullerenes, in their turn, can be also hydrogenated, becoming fulleranes, and photo-dissociated, losing carbon and hydrogen atoms. The carbon loss leads to shrinking of fullerene cages to smaller ones. We calculate the abundance of PAHs and fullerenes of different sizes and hydrogenation level depending on external conditions: the gas temperature, intensity of radiation field, number density of hydrogen atoms, carbon atoms, and electrons. We highlight the conditions, which are favourable for fullerene formation from PAHs, and we conclude that this mechanism works not only in H-poor environment but also at modest values of hydrogen density up to 104 cm−3. We found that fulleranes can be formed in the ISM, although the fraction of carbon atoms locked in them can be maximum around 10−9. We applied our model to two photo-dissociation regions, Orion Bar and NGC 7023. We compare our estimates of the fullerene abundance and synthetic band intensities in these objects with the observations and conclude that our model gives good results for the closest surroundings of ionizing stars. We also demonstrate that additional fullerene formation channels should operate along with ultraviolet (UV)-induced formation to explain abundance of fullerenes far from UV sources. [ABSTRACT FROM AUTHOR]

Shockwaves driven by supernovae both destroy dust and reprocess the surviving grains, greatly affecting the resulting dust properties of the interstellar medium (ISM). While these processes have been extensively studied theoretically, observational constraints are limited. We use physically motivated models of dust emission to fit the infrared (IR) spectral energy distributions of seven Galactic supernova remnants, allowing us to determine the distribution of dust mass between diffuse and dense gas phases, and between large and small grain sizes. We find that the dense (⁠|$\sim \! 10^3\ {\rm cm}^{-3}$|⁠), relatively cool (⁠|$\sim \! 10^3\ {\rm K}$|⁠) gas phase contains |$\gt 90{{\ \rm per\ cent}}$| of the dust mass, making the warm dust located in the X-ray emitting plasma (⁠|$\sim \! 1\ {\rm cm}^{-3}$| / |$10^6\ {\rm K}$|⁠) a negligible fraction of the total, despite dominating the mid-IR emission. The ratio of small (⁠|$\lesssim\!{10}\ {\rm nm}$|⁠) to large (⁠|$\gtrsim \! 0.1\ {\rm \mu m}$|⁠) grains in the cold component is consistent with that in the ISM, and possibly even higher, whereas the hot phase is almost entirely devoid of small grains. This suggests that grain shattering, which processes large grains into smaller ones, is ineffective in the low-density gas, contrary to model predictions. Single-phase models of dust destruction in the ISM, which do not account for the existence of the cold swept-up material containing most of the dust mass, are likely to greatly overestimate the rate of dust destruction by supernovae. [ABSTRACT FROM AUTHOR]

Dust polarization observations at optical wavelengths help us to understand the dust grain properties and trace the plane-of-the-sky component of the magnetic field. In this study, we make use of the I -band polarization data acquired from AIMPOL along with the distances (d) and extinction (AV) data to study the variation of polarization fraction (P) as a function of AV and d towards the star-forming region, NGC 1893. We employ a broken power-law fit and Bayesian analysis on extinction (AV) versus polarization efficiency (P / AV) and distance (d) versus rate of polarization (P / d). We find that P / AV shows a break at an extinction of ∼0.9 mag, whereas P / d exhibits a break at a distance of ∼1.5 kpc. Based on these, we categorize the dust towards NGC 1893 into two populations: (i) foreground dust confined to AV < ∼1 mag and distance up to ∼2 kpc and (ii) Perseus spiral arm dust towards NGC 1893 characterized with AV > ∼1 mag and distance beyond ∼2 kpc. Foreground dust exhibits higher polarization efficiency but a lower polarization rate, whereas Perseus dust shows a lower polarization efficiency but a slightly higher polarization rate. Hence, we suggest that while polarization efficiency reveals the dust grain alignment, the rate of polarization infers about the distribution of dust grains towards NGC 1893. Further, we also shed a light on the spatial variation of intrinsic polarization and magnetic field orientation, and other parameters within the intracluster medium of NGC 1893. [ABSTRACT FROM AUTHOR]

We present new room-temperature 1100–1800-cm−1 spectra of melilite silicates and 600–2000-cm−1 spectra of three randomly orientated fine-grained carbonates to determine the possible carrier(s) of a 6.9- μ m absorption feature observed in a variety of dense astronomical environments, including young stellar objects and molecular clouds. We focus on the low-mass post-asymptotic giant branch star Sakurai's Object, which has been forming substantial quantities of carbonaceous dust since an eruptive event in the 1990s. Large melilite grains cannot be responsible for the 6.9- μ m absorption feature because the similarly shaped feature in the laboratory spectrum was produced by very low (0.1 per cent by mass) carbonate contamination, which was not detected at other wavelengths. Due to the high band strength of the 6.9- μ m feature in carbonates, we conclude that carbonates carry the astronomical 6.9- μ m feature. Replacement of melilite with carbonates in models of Sakurai's Object improves fits to the 6–7- μ m Spitzer spectra without significantly altering other conclusions of Bowey's previous models except that there is no link between the feature and the abundance of melilite in meteorites. With magnesite (MgCO3), the abundance of 25- μ m-sized SiC grains is increased by 10–50 per cent and better constrained. The mass of carbonate dust is similar to the mass of polycyclic aromatic hydrocarbon dust. Existing experiments suggest that carbonates are stable below 700 K; however, it is difficult to ascertain the applicability of these experiments to astronomical environments, and more studies are required. [ABSTRACT FROM AUTHOR]

The presence of charged dust grains is known to have a profound impact on the physical evolution of the multiphase interstellar medium (ISM). Despite its importance, this process is still poorly explored in numerical simulations due to its complex physics and the tight dependence on the environment. Here, we introduce a novel implementation of grain charging in the cosmological radiative transfer code crash. We first benchmark the code predictions on a series of idealized dusty H  ii regions created by a single star, in order to assess the impact of grain properties on the resulting spatial distribution of charges. Secondly, we perform a realistic radiative transfer simulation of a star-forming region extracted from a dusty galaxy evolving in the Epoch of Reionization. We find that ∼13 per cent of the total dust mass gets negatively charged, mainly silicate and graphite grains of radius 10−3  |$\mu$| m. A complex spatial distribution of grain charges is also found, primarily depending on the exposure to stellar radiation and strongly varying along different lines of sight, as a result of radiative transfer effects. We finally assess the impact of grain properties (both chemical composition and size) on the resulting charge distribution. The new implementation described here will open up a wide range of possible studies investigating the physical evolution of the dusty ISM, nowadays accessible to observations of high- and low- redshift galaxies. [ABSTRACT FROM AUTHOR]

We develop a cosmological model for the evolution of dust grains in galaxies with a distribution of sizes in order to understand the origin of the Milky Way dust extinction curve. Our model considers the formation of active dust in evolved stars, growth by accretion and coagulation, and destruction processes via shattering, sputtering, and astration in the ISM of galaxies over cosmic time. Our main results follow. Galaxies in our cosmological model with masses comparable to the Milky Way's at z ∼ 0 exhibit a diverse range of extinction laws, though with slopes and bump strengths comparable to the range observed in the Galaxy. The progenitors of the Milky Way have steeper slopes, and only flatten to slopes comparable to the Galaxy at z ∼ 1. This owes to increased grain growth rates at late times/in high-metallicity environments driving up the ratio of large to small grains, with a secondary dependence on the graphite-to-silicate ratio evolution. The UV bump strengths depend primarily on the graphite-to-silicate ratio, and remain broadly constant in MW-like galaxies between z = 3 and z = 0, though show slight variability. Our models span comparable regions of bump-slope space as sightlines in the Galaxy do, though there is a lack of clear relationship between the model slopes and bump strengths owing to variations among galaxies in the graphite-to-silicate ratio. Our model provides a novel framework to study the origins and variations of dust extinction curves in galaxies over cosmic time. [ABSTRACT FROM AUTHOR]

We present a novel scenario for the growth of dust grains in galaxies at high redshift (z  ∼ 6). In our model, the mechanical feedback from massive star clusters evolving within high-density pre-enriched media allows to pile up a large amount of matter into massive supershells. If the gas metallicity (≥Z⊙), number density (≥106 cm−3), and dust-to-gas mass ratio (∼1/150 × Z) within the supershell are sufficiently large, such supershells may become optically thick to the starlight emerging from their host star clusters and even to radiation from the cosmic microwave background (CMB). Based on semi-analytic models, we argue that this mechanism, occurring in the case of massive (⁠|${\ge} 10^7\, {\rm M}_{\odot }$|⁠) molecular clouds hosting |${\ge} 10^6\, {\rm M}_{\odot }$| star clusters, allows a large mass of gas and dust to acquire a temperature below that of the CMB, whereupon dust grain growth may occur with ease. In galaxies with total stellar mass M *, grain growth within supershells may increase the dust mass by |${\sim} 10^6\, {\rm M}_{\odot } (M_{*}/10^{8}\, {\rm M}_{\odot })$|⁠. [ABSTRACT FROM AUTHOR]

A necessary first step for dust removal in protoplanetary disc winds is the delivery of dust from the disc to the wind. In the case of ionized winds, the disc and wind are sharply delineated by a narrow ionization front where the gas density and temperature vary by more than an order of magnitude. Using a novel method that is able to model the transport of dust across the ionization front in the presence of disc turbulence, we revisit the problem of dust delivery. Our results show that the delivery of dust to the wind is determined by the vertical gas flow through the disc induced by the mass-loss, rather than turbulent diffusion (unless the turbulence is strong, i.e. α ≳ 0.01). Using these results, we provide a simple relation between the maximum size of particle that can be delivered to the wind and the local mass-loss rate per unit area from the wind. This relation is independent of the physical origin of the wind and predicts typical sizes in the 0.01– |$1\, \rm{\mu m}$| range for extreme-ultraviolet- or X-ray-driven winds. These values are a factor of ∼10 smaller than those obtained when considering only whether the wind is able to carry away the grains. [ABSTRACT FROM AUTHOR]

We have detected a broad interstellar absorption band centred close to 7700 Å and with a full width at half-maximum (FWHM) of 176.6 ± 3.9 Å. This is the first such absorption band detected in the optical range and is significantly wider than the numerous diffuse interstellar bands (DIBs). It remained undiscovered until now because it is partially hidden behind the A telluric band produced by O2. The band was discovered using STIS@HST spectra and later detected in a large sample of stars of diverse type (OB stars, BA supergiants, red giants), using further STIS and ground-based spectroscopy. The EW of the band is measured and compared with our extinction and K  i  λλ7667.021, 7701.093 measurements for the same sample. The carrier is ubiquitous in the diffuse and translucent Galactic interstellar medium (ISM) but is depleted in the environment around OB stars. In particular, it appears to be absent or nearly so in sightlines rich in molecular carbon. This behaviour is similar to that of the σ-type DIBs, which originate in the low/intermediate-density UV-exposed ISM but are depleted in the high-density UV-shielded molecular clouds. We also present an update on our previous work on the relationship between E (4405–5495) and R 5495 and incorporate our results into a general model of the ISM. [ABSTRACT FROM AUTHOR]

Utilizing several instruments on 4–8 m telescopes, we have observed a large sample of objects in the mid-infrared (8–13  μ m). These comprise a few evolved stars, multiple envelopes of embedded young stellar objects (YSOs) or compact H-II regions, and several sightlines through the interstellar medium (ISM). The latter is where dust resides – and is potentially modified – between its formation in evolved stellar outflows and deposition in molecular clouds. In most objects, we detect not only the well-known 9.7  μ m absorption feature of amorphous silicates but also a second absorption band around 11.1  μ m whose carrier is attributed to crystalline forsterite. We propose that crystalline silicates are essentially ubiquitous in the ISM and earliest phases of star formation, and are evolutionary precursors to T-Tauri and Herbig stars where such silicates have been commonly found. Modelling shows that in most YSOs, H-II regions and ISM cases, the forsterite mass fraction is between 1 and 2 per cent, suggesting that the younger phases inherit their abundance from the ISM. However, several sources show much stronger features (abundances ≥3 per cent). This suggests that significant processing, perhaps crystallization by thermal annealing, occurs early on in star formation. Most intriguing is the first detection of crystalline silicate in the diffuse ISM. We propose that our observed abundance is consistent with a mass fraction of crystalline silicates of 10–20 per cent injected into the ISM, along with commonly accepted lifetimes against their destruction, but only if cosmic ray-induced amorphization is insignificant over a few Giga years. [ABSTRACT FROM AUTHOR]

Stacked analyses of galaxy clusters at low-to-intermediate redshift show signatures attributable to dust, but the origin of this dust is uncertain. We test the hypothesis that the bulk of cluster dust derives from galaxy ejecta. To do so, we employ dust abundances obtained from detailed chemical evolution models of galaxies. We integrate the dust abundances over cluster luminosity functions (one-slope and two-slope Schechter functions). We consider both a hierarchical scenario of galaxy formation and an independent evolution of the three main galactic morphologies: elliptical/S0, spiral and irregular. We separate the dust residing within galaxies from the dust ejected in the intracluster medium. To the latter, we apply thermal sputtering. The model results are compared to low-to-intermediate redshift observations of dust masses. We find that in any of the considered scenarios, elliptical/S0 galaxies contribute negligibly to the present-time intracluster dust, despite producing the majority of gas-phase metals in galaxy clusters. Spiral galaxies, instead, provide both the bulk of the spatially unresolved dust and of the dust ejected into the intracluster medium. The total dust-to-gas mass ratio in galaxy clusters amounts to 10−4, while the intracluster medium dust-to-gas mass ratio amounts to 10−6 at most. These dust abundances are consistent with the estimates of cluster observations at 0.2 <  z  < 1. We propose that galactic sources, spiral galaxies in particular, are the major contributors to the cluster dust budget. [ABSTRACT FROM AUTHOR]

Interstellar dust (ISD) penetrates into the heliosphere/astrosphere due to relative motion of the Sun and the local interstellar medium (LISM). Inside the heliosphere/astrosphere and at the heliospheric boundaries, where the solar/stellar wind interacts with LISM, distribution of the ISD is modified due to an action of electromagnetic forces, the solar gravitation, and radiation pressure. In this paper, we show that the distribution of the ISD particles in the heliosphere has peculiarities of high-density layers. In order to understand the nature of the peculiarities Osiptsov's Lagrangian method has been employed and developed for the case when the force acting on the particles has discontinuity as it is for the electromagnetic force at the helioshperic current sheet (HCS). In the result of the modelling, we demonstrate existence of multiple layers of high density of the ISD located at 0.03–10 au north and south with respect to the HCS. [ABSTRACT FROM AUTHOR]

We present predictions for the evolution of the galaxy dust-to-gas ratio (DGR) and dust-to-metal ratio (DTM) from z = 0 → 6, using a model for the production, growth, and destruction of dust grains implemented into the simba cosmological hydrodynamic galaxy formation simulation. In our model, dust forms in stellar ejecta, grows by the accretion of metals, and is destroyed by thermal sputtering and supernovae. Our simulation reproduces the observed dust mass function at z = 0, but modestly underpredicts the mass function by ∼×3 at z  ∼ 1–2. The z = 0 DGR versus metallicity relationship shows a tight positive correlation for star-forming galaxies, while it is uncorrelated for quenched systems. There is little evolution in the DGR–metallicity relationship between z = 0 and 6. We use machine learning techniques to search for the galaxy physical properties that best correlate with the DGR and DTM. We find that the DGR is primarily correlated with the gas-phase metallicity, though correlations with the depletion time-scale, stellar mass, and gas fraction are non-negligible. We provide a crude fitting relationship for DGR and DTM versus the gas-phase metallicity, along with a public code package that estimates the DGR and DTM given a set of galaxy physical properties. [ABSTRACT FROM AUTHOR]

The carriers of the still (mostly) unidentified diffuse interstellar bands (DIBs) have been a long-standing mystery ever since their first discovery exactly 100 yr ago. In recent years, the ubiquitous detection of a large number of DIBs in a wide range of Galactic and extragalactic environments has led to renewed interest in connecting the occurrence and properties of DIBs to the physical and chemical conditions of the interstellar clouds, with particular attention paid to whether the DIB strength is related to the shape of the interstellar extinction curve. To shed light on the nature and origin of the DIB carriers, we investigate the relation between the DIB strength and RV , the total-to-selective extinction ratio, which characterizes how the extinction varies with wavelength (i.e. the shape of the extinction curve). We find that the DIB strength and RV are not related if we represent the strength of a DIB by its reddening-normalized equivalent width (EW), in contrast to the earlier finding of an anticorrelation in which the DIB strength is measured by the extinction-normalized EW. This raises a fundamental question about the appropriate normalization for the DIB EW. We argue that the hydrogen column density is a more appropriate normalization than extinction and reddening. [ABSTRACT FROM AUTHOR]

We present a suite of 34 high-resolution cosmological zoom-in simulations consisting of thousands of haloes up to |$M_{\rm halo}\sim 10^{12}\, \mathrm{M}_{\odot }$| (⁠|$M_{\ast }\sim 10^{10.5}\, \mathrm{M}_{\odot }$|⁠) at z ≥ 5 from the Feedback in Realistic Environments project. We post-process our simulations with a three-dimensional Monte Carlo dust radiative transfer code to study dust attenuation, dust emission, and dust temperature within these simulated z ≥ 5 galaxies. Our sample forms a tight correlation between infrared excess (IRX ≡ F IR/ F UV) and ultraviolet (UV)-continuum slope (βUV), despite the patchy, clumpy dust geometry shown in our simulations. We find that the IRX–βUV relation is mainly determined by the shape of the attenuation law and is independent of its normalization (set by the dust-to-gas ratio). The bolometric IR luminosity (L IR) correlates with the intrinsic UV luminosity and the star formation rate (SFR) averaged over the past 10 Myr. We predict that at a given L IR, the peak wavelength of the dust spectral energy distributions for z ≥ 5 galaxies is smaller by a factor of 2 (due to higher dust temperatures on average) than at z  = 0. The higher dust temperatures are driven by higher specific SFRs and SFR surface densities with increasing redshift. We derive the galaxy UV luminosity functions (UVLFs) at z  = 5–10 from our simulations and confirm that a heavy attenuation is required to reproduce the observed bright-end UVLFs. We also predict the IR luminosity functions (IRLFs) and UV luminosity densities at z  = 5–10. We discuss the implications of our results on current and future observations probing dust attenuation and emission in z ≥ 5 galaxies. [ABSTRACT FROM AUTHOR]

We find a tight correlation between the dust extinction, traced by the Balmer Decrement (BD = H α/H β), the CO(1-0) line luminosity (L CO), and total molecular gas mass (M H2) in a sample of 222 local star-forming galaxies drawn from the xCOLD GASS survey. As expected, the galaxy disc inclination affects the correlation by inducing a saturation of the Balmer decrement on highly inclined galaxies. Once this effect is taken into account, L CO and M H2 can be expressed as a function of BD with a scatter of ∼0.3 dex. We do not find any dependence on galaxy size, mass, morphology, star formation activity, and gas metallicity. The correlation disappears if the atomic gas phase is considered. This is likely due to the fact that the region traced by the BD, the stellar disc, is much smaller than the HI disc. [ABSTRACT FROM AUTHOR]

We present a statistical study of the relative orientation in the plane of the sky between interstellar magnetic fields and filaments hosting cold clumps. For the first time, we consider both the density of the environment and the density contrast between the filaments and their environment. Moreover, we geometrically distinguish between the clumps and the remaining portions of the filaments. We infer the magnetic field orientations in the filaments and in their environment from the Stokes parameters, 1 assuming optically thin conditions. Thus, we analyse the relative orientations between filaments, embedded clumps, internal and background magnetic fields, depending on their environment and evolutionary stages. We recover the previously observed trend for filaments in low column density environments to be aligned parallel to the background magnetic field; however, we find that this trend is significant only for low-contrast filaments, whereas high-contrast filaments tend to be randomly orientated with respect to the background magnetic field. Filaments in high column density environments do not globally show any preferential orientation, although low-contrast filaments alone tend to have perpendicular relative orientation with respect to the background magnetic field. For a subsample of nearby filaments, for which volume densities can be derived, we find a clear transition in the relative orientation with increasing density, at n H ∼ 103 cm−3, changing from mostly parallel to mostly perpendicular in the off-clump portions of filaments and from even to bimodal in clumps. Our results confirm a strong interplay between interstellar magnetic fields and filaments during their formation and evolution. [ABSTRACT FROM AUTHOR]

The existence of cosmic dust is attested by the interstellar extinction and polarization, IR emission and absorption spectra, and elemental depletion patterns. Dust grains are efficiently processed or even destroyed in shocks, molecular clouds, or protoplanetary disks. A considerable amount of dust has to be re-formed in the ISM. In various astrophysical environments, dust grains are covered by molecular ices and therefore contribute or catalytically influence the chemical reactions in these layers. Laboratory experiments are desperately required to understand the evolution of grains and grain/ice mixtures in molecular clouds and early planetary disks. This review considers recent progress in laboratory approaches to dust/ice experiments. [ABSTRACT FROM AUTHOR]

Complex organic molecules (COMs) have been detected in the gas-phase in cold and lightless molecular cores. Recent solid-state laboratory experiments have provided strong evidence that COMs can be formed on icy grains through 'non-energetic' processes. In this contribution, we show that propanal and 1-propanol can be formed in this way at the low temperature of 10 K. Propanal has already been detected in space. 1-propanol is an astrobiologically relevant molecule, as it is a primary alcohol, and has not been astronomically detected. Propanal is the major product formed in the C2H2 + CO + H experiment, and 1-propanol is detected in the subsequent propanal + H experiment. ALMA observations towards IRAS 16293-2422B are discussed and provide a 1-propanol:propanal upper limit of < 0.35–0.55, which are complemented by computationally-derived activation barriers in addition to the performed laboratory experiments. [ABSTRACT FROM AUTHOR]

A key element when modeling dust in any astrophysical environment is a self-consistent treatment of the evolution of the dust material properties (size distribution, chemical composition and structure) as they react to and adjust to the local radiation field intensity and hardness and to the gas density and dynamics. The best way to achieve this goal is to anchore as many model parameters as possible to laboratory data. In this paper, I present two examples to illustrate how outstanding questions in dust modeling have been/are being moved forward by recent advances in laboratory astrophysics and what laboratory data are still needed to further advance dust evolution models. [ABSTRACT FROM AUTHOR]

Asteroid 1I/'Oumuamua is the first observed interstellar object. Its light-curve amplitude indicates that the object is highly elongated with an axial ratio of at least 5:1. The absence of such elongated asteroids in the Solar system and the apparent lack of observed interstellar objects are intriguing problems. Here we show that 'Oumuamua may have originated as a slightly elongated asteroid about 500 × 300 m in size. Surface erosion, caused by interstellar dust bombardment, subsequently increased the axial ratio. Simply travelling through the interstellar medium for 0.03 to 2 Gyr would have sufficed to give 1I its present shape. Passing through a 10 pc dust cloud with a grain density of 10−23 g cm−3 at 50 km s−1 would have had a similar effect on 'Oumuamua's form. Smaller objects of around 100 m in diameter can travel the Galactic disc for merely 30 Myr before they are disrupted. This could explain the small number of interstellar objects observed to date. [ABSTRACT FROM AUTHOR]

. High Mass X-ray Binaries (HMXB) have been revealed by a wealth of multi-wavelength observations, from X-ray to optical and infrared domain. After describing the 3 different kinds of HMXB, we focus on 3 HMXB hosting supergiant stars: IGR J16320-4751, IGR J16465-4507 and IGR J16318-4848, respectively called "The Good", "The Bad" and "The Ugly". We review in these proceedings what the observations of these sources have brought to light concerning our knowledge of HMXB, and what part still remains in the dark side. Many questions are still pending, related to accretion processes, stellar wind properties in these massive and active stars, and the overall evolution due to transfer of mass and angular momentum between the companion star and the compact object. Future observations should be able to answer these questions, which constitute the dark side of HMXB. [ABSTRACT FROM AUTHOR]

Characterizing the properties and the evolution of the first stars and galaxies is a challenging task for traditional galaxy surveys since they are sensitivity limited and can only detect the brightest light sources. Three-dimensional intensity mapping (IM) of transition lines can be a valuable alternative to study the high redshift Universe given that this technique avoids sensitivity limitation problems by measuring the overall emission of a line, with a low resolution, without resolving its sources. While 21cm line IM surveys probe neutral hydrogen gas and can, therefore, be used to probe the state of the IGM and the evolution of the ionization field during the Epoch of Reionization (EoR). IM surveys of other lines, such as CO, CII, Ly-alpha or H-alpha, can be used to probe the galaxies which emitted most of the ionizing radiation responsible for the EoR. These lines will trace the different ISM gas phases, the excitation state of this gas, its metallicity, etc. This study addresses IM of multiple transition lines and how it can be used to probe the EoR and to constrain the redshift evolution of galaxy properties. [ABSTRACT FROM AUTHOR]

Surveys of pulsating stars in the inner Galaxy have been very limited, but recent large-scale surveys are rapidly bringing us new samples of various kinds of variable stars and new insights into stellar populations therein. Because of the severe interstellar extinction along the Galactic disc, the stellar populations in the inner Galaxy are more easily observed in the infrared, but even in the infrared the interstellar extinction may cause a serious problem in revealing their accurate characteristics. Here we review recent discoveries of Cepheids and Miras, two kinds of luminous pulsating stars with period–luminosity relation, in the inner Galaxy. [ABSTRACT FROM AUTHOR]

Dust Obscured Galaxies (DOGs) are observed as far as the reionization epoch. Their cosmic density peaks together with the star formation rate. DOGs also rule the star formation in high stellar mass galaxies. In this work we used a chemodynamical model to evolve the amount of dust in galaxies. We ran forty models varying initial mass and both dust formation efficiency and dust production. We find that for high star formation rate systems the accretion dominates the dust evolution and it explains high-z DOGs. Low star formation rate systems are better suited to investigate dust production. Also, we find that a MDust/MGas versus MDust/M* diagram is a good tracer of galaxy evolution. [ABSTRACT FROM AUTHOR]

Edge-on spiral galaxies offer a unique perspective on the vertical structure of spiral disks, both stars and the iconic dark dustlanes. The thickness of these dustlanes can now be resolved for the first time with Herschel in far-infrared and sub-mm emission. We present NHEMESES, an ongoing project that targets 12 edge-on spiral galaxies with the PACS and SPIRE instruments on Herschel. These vertically resolved observations of edge-on spirals will impact on several current topics.First and foremost, these Herschel observations will settle whether or not there is a phase change in the vertical structure of the ISM with disk mass. Previously, a dramatic change in dustlane morphology was observed as in massive disks the dust collapses into a thin lane. If this is the case, the vertical balance between turbulence and gravity dictates the ISM structure and consequently star-formation and related phenomena (spiral arms, bars etc.). We specifically target lower mass nearby edge-ons to complement existing Herschel observations of high-mass edge-on spirals (the HEROES project).Secondly, the combined data-set, together with existing Spitzer observations, will drive a new generation of spiral disk Spectral Energy Distribution models. These model how dust reprocesses starlight to thermal emission but the dust geometry remains the critical unknown.And thirdly, the observations will provide an accurate and unbiased census of the cold dusty structures occasionally seen extending out of the plane of the disk, when backlit by the stellar disk. To illustrate the NHEMESES project, we present early results on NGC 4244 and NGC 891, two well studies examples of a low and high-mass edge-on spiral. [ABSTRACT FROM PUBLISHER]

The interstellar medium constitutes a physically and chemically complex component of galaxies and is important in the cycle of matter and the evolution of stars. From various spectroscopic clues we now know that the interstellar medium is rich in organic compounds. However, identifying the exact nature of all these components remains a challenge. In particular the identification of the so-called diffuse band carriers has been alluding astronomers for almost a century.In recent decades, observational, experimental and theoretical advances have rapidly lead to renewed interest in the diffuse interstellar bands (DIBs). This has been instigated partly by their perceived relation to the infrared aromatic emission bands, the UV extinction bump and far-UV rise, and the growing number of (small) organic molecules identified in space.This chapter gives an overview of the observational properties and behaviour of the DIBs, and their presence throughout the Universe. I will highlight recent progress in identifying their carriers and discuss their potential as tracers and probes of (extra)-Galactic ISM conditions. [ABSTRACT FROM PUBLISHER]

Connecting the endpoints of massive star evolution with the various types of core-collapse supernovae (SNe) is ultimately the fundamental puzzle to be explored and solved. We can assemble clues indirectly, e.g., from information about the environments in which stars explode and establish constraints on the evolutionary phases of these stars. However, this is best accomplished through direct identification of the actual star that has exploded in pre-supernova imaging, preferably in more than one photometric band, where color and luminosity for the star can be precisely measured. We can then interpret the star's properties in light of expectations from the latest massive stellar evolutionary models, to attempt to assign an initial mass to the progenitor. So far, this has been done most successfully for SNe II-P, for which we now know that red supergiants in a relatively limited initial mass range are responsible. More recently, we have limited examples of the progenitors of SNe II-L, IIn, and IIb. The progenitors of SNe Ib and Ic, however, have been elusive so far; I will discuss the current status of our knowledge of this particular channel. [ABSTRACT FROM PUBLISHER]

We have mapped the nearby face-on spiral galaxy M 33 in the 1.1 mm dust continuum using AzTEC on Atacama Submillimeter Telescope Experiment (ASTE). The preliminary results are presented here. The observed dust has a characteristic temperature of ~ 21 K in the central kpc, radially declining down to ~ 13 K at the edge of the star forming disk. We compare the dust temperatures with KS band flux and star formation tracers. Our results imply that cold dust heating may be driven by long-lived stars even nearby star forming regions. [ABSTRACT FROM PUBLISHER]

The infrared astronomical satellite AKARI performed an all sky survey at six infrared bands. We report here on the calibration of the all-sky image data, observed in the four long wavelength bands with the FIS instrument (AKARI Far-infrared All Sky Survey : AFASS). The preliminary image attains a calibration uncertainty and sensitivity of better than ~ 30% and ~ 10 MJy str−1, respectively, for all four bands. The point spread function (PSF) is obtained via a stacking technique. The data are shown to be useful for exploring the internal structure and dust spectral energy distributions (SEDs) of nearby galaxies. [ABSTRACT FROM PUBLISHER]

The Spitzer Space Telescope has discovered several objects with unusual spectra, where the emission features from polycyclic aromatic hydrocarbons (PAHs) are shifted to longer wavelengths than normally observed. Previously, only two of these class C PAH spectra had been identified. The new and larger sample reveals that PAHs emit at longer wavelengths when processed by cooler radiation fields. Limited laboratory data show that samples with mixtures of aromatic and aliphatic hydrocarbons produce emission features at longer wavelengths than purely aromatic samples. The aliphatic bonds are more fragile and would only survive in cooler radiation fields. In harsher radiation fields, the aliphatics attached to the aromatic hydrocarbons are destroyed. [ABSTRACT FROM PUBLISHER]