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Dust in the interstellar medium (ISM) is critical to the absorption and intensity of emission profiles used widely in astronomical observations, and necessary for star and planet formation. Supernovae (SNe) both produce and destroy ISM dust. In particular the destruction rate is difficult to assess. Theory and prior simulations of dust processing by SNe in a uniform ISM predict quite high rates of dust destruction, potentially higher than the supernova dust production rate in some cases. Here we show simulations of supernova-induced dust processing with realistic ISM dynamics including magnetic field effects and demonstrate how ISM inhomogeneity and magnetic fields inhibit dust destruction. Compared to the non-magnetic homogeneous case, the dust mass destroyed within 1 Myr per SNe is reduced by more than a factor of two, which can have a great impact on the ISM dust budget. The interstellar medium (ISM) is critical to galaxy evolution. Here, the authors show dust processing modelling applied to magnetohydrodynamic simulations to explicitly follow dust destruction by the combined effects of grain-grain collisions and ion-sputtering induced by a supernova blast wave in a turbulent multiphase, magnetized ISM.

Imaging Mie polarimetry is key to determining spatially resolved information about the properties, i.e. refractive index and grain size, of particle clouds, such as during the growth process in reactive particle producing plasmas. Asymmetries in the intensity maps of the different Stokes parameters resulting from the anisotropic scattering of polarized laser light complicate the analysis and require the use of radiative transfer (RT) simulations. We use RT simulations to investigate the asymmetric scattering behavior based on a model of a typical reactive argon-acetylene plasma. We address possible misinterpretations and explore the potential for analyzing particle properties. We find that the asymmetric pattern of the intensity distributions is highly dependent on the refractive index, providing the potential to determine the refractive index and grain size at any time during the growth process.

Dust in the interstellar medium (ISM) is critical to the absorption and intensity of emission profiles used widely in astronomical observations, and necessary for star and planet formation. Supernovae (SNe) both produce and destroy ISM dust. In particular the destruction rate is difficult to assess. Theory and prior simulations of dust processing by SNe in a uniform ISM predict quite high rates of dust destruction, potentially higher than the supernova dust production rate in some cases. Here we show simulations of supernova-induced dust processing with realistic ISM dynamics including magnetic field effects and demonstrate how ISM inhomogeneity and magnetic fields inhibit dust destruction. Compared to the non-magnetic homogeneous case, the dust mass destroyed within 1 Myr per SNe is reduced by more than a factor of two, which can have a great impact on the ISM dust budget.

Context. While supernova remnants (SNRs) are observed to produce up to 1 M\\(_\\) of dust, the amount of dust destroyed by the forward shock (FS) is poorly constrained, raising the question whether they are net dust producers or destroyers. Aims. We aim to estimate the dust destruction efficiency of SNR FSs in a realistically turbulent interstellar medium (ISM) during their most destructive phase, and assess dust shielding by high density filaments during this period. Methods. We run 3D turbulence simulations for different turbulent Mach numbers (0-3) and average ISM densities (1-100 cm\\(^-3\\)) to resemble observations of the turbulent ISM. We then set off a supernova to trace its 3D magnetohydrodynamical evolution for 10 kyr. Finally, we run post-processing simulations to study the dust transport and destruction by the SNR FS, considering gas and plasma drag, kinetic and thermal sputtering, and grain-grain collisions, and either silicate or carbonaceous dust. Results. The dust destruction rate of the FS strongly depends on the average ISM density and turbulence strength, varying between 27-92% (0.85-11.0 M\\(_\\)) in the studied 10 kyr. Overall, dust is less efficiently destroyed in a low density medium (1 cm\\(^-3\\), 27-57%) than in intermediate (10 cm\\(^-3\\), 46-92%) and high densities (100 cm\\(^-3\\), 73-87%). The FS destroys 8-34% less dust in high Mach turbulence compared to a homogeneous medium. Furthermore, carbonaceous grains are more robust (up to 21% more) than silicates. Conclusions. Filaments can partly shield dust from destruction in the first 10 kyr, however, always more than 0.85 M\\(_\\) of dust is destroyed, making most SNRs dust sinks under the conditions explored in this work. The destruction efficiency of the SNRs with less than 1 M\\(_\\) of destroyed dust has not yet plateaued so that they are most likely also net dust destroyers by the end of their lifetime.

Quantifying the efficiency of dust destruction in the interstellar medium (ISM) due to supernovae (SNe) is crucial for the understanding of galactic dust evolution. We present 3D hydrodynamic simulations of an SN blast wave propagating through the ISM. The interaction between the forward shock of the remnant and the surrounding ISM leads to destruction of ISM dust by the shock heated gas. We consider the dust processing due to ion sputtering, accretion of atoms/molecules and grain-grain collisions. Using 2D slices from the simulation timeseries, we apply post-processing calculations using the Paperboats code. We find that efficiency of dust destruction depends strongly on the rate of grain shattering due to grain-grain collisions. The effective dust destruction is similar to previous theoretical estimates when grain-grain collisions are omitted, but with grain shattering included, the net destruction efficiency is roughly one order of magnitude higher. This result indicates that the dust destruction rate in the ISM may have been severely underestimated in previous work, which only exacerbates the dust-budget crises seen in galaxies at high redshifts.

Excess over the stellar photospheric emission of main-sequence stars has been found in interferometric near-infrared observations, and is attributed to the presence of hot exozodiacal dust (HEZD). As part of our effort to detect and characterize HEZD around the nearby A3 V star Fomalhaut, we carried out the first interferometric observations with the MATISSE instrument at the VLTI in the photometric bands L and M for the Fomalhaut system. Assuming a dust distribution either as a narrow ring or spherical shell for modeling the HEZD, we aim to constrain the HEZD parameters by generating visibilities and fitting them to the MATISSE data using different approaches. The L band data provide a marginal detection of circumstellar radiation, potentially caused by the presence of HEZD, which is only the second detection of HEZD emission in the L band. An analysis of the data with different fitting approaches showed that the best-fit values for the HEZD parameters are consistent with those of previous Fomalhaut observations, which underlines the functionality of MATISSE. Assuming a dust ring, it would have an inner ring radius of \\(0.11\\ au\\), an outer ring radius of \\(0.12\\ au\\), a narrow dust grain size distribution around a dust grain radius constrained by \\(0.53\\ \\), and a total dust mass of \\(3.25 10^-10\\ M_\\). Finally, the results indicate that the choice of the geometric model has a more significant impact on the derived dust-to-star flux ratio than the specific fitting approach applied. Since different dust-to-star flux ratios can result from the applied fitting approaches, this also has an impact on the parameter values of the HEZD around Fomalhaut and most likely for other HEZD systems. Moreover, further NIR and MIR data are required for a more comprehensive description of the emission originating in the vicinity of Fomalhaut.

ALMA surveys have suggested that protoplanetary disks are not massive enough to form the known exoplanet population, under the assumption that the millimeter continuum emission is optically thin. In this work, we investigate how the mass determination is influenced when the porosity of dust grains is considered in radiative transfer models. The results show that disks with porous dust opacities yield similar dust temperature, but systematically lower millimeter fluxes compared to disks incorporating compact dust grains. Moreover, we recalibrate the relation between dust temperature and stellar luminosity for a wide range of stellar parameters, and calculate the dust masses of a large sample of disks using the traditionally analytic approach. The median dust mass from our calculation is about 6 times higher than the literature result, and this is mostly driven by the different opacities of porous and compact grains. A comparison of the cumulative distribution function between disk dust masses and exoplanet masses show that the median exoplanet mass is about 2 times lower than the median dust mass, if grains are porous, and there are no exoplanetary systems with masses higher than the most massive disks. Our analysis suggests that adopting porous dust opacities may alleviate the mass budget problem for planet formation. As an example illustrating the combined effects of optical depth and porous dust opacities on the mass estimation, we conduct new IRAM/NIKA-2 observations toward the IRAS 04370+2559 disk and perform a detailed radiative transfer modeling of the spectral energy distribution. The best-fit dust mass is roughly 100 times higher than the value from the traditionally analytic calculation. Future spatially resolved observations at various wavelengths are required to better constrain the dust mass.

Dust grains form in the clumpy ejecta of core-collapse supernovae where they are subject to the reverse shock, which is able to disrupt the clumps and destroy the grains. Important dust destruction processes include thermal and kinetic sputtering as well as fragmentation and grain vaporization. In the present study, we focus on the effect of magnetic fields on the destruction processes. We have performed magneto-hydrodynamical simulations using AstroBEAR to model a shock wave interacting with an ejecta clump. The dust transport and destruction fractions are computed using our post-processing code Paperboats in which the acceleration of grains due to the magnetic field and a procedure that allows partial grain vaporization have been newly implemented. For the oxygen-rich supernova remnant Cassiopeia A we found a significantly lower dust survival rate when magnetic fields are aligned perpendicular to the shock direction compared to the non-magnetic case. For a parallel field alignment, the destruction is also enhanced but at a lower level. The survival fractions depend sensitively on the gas density contrast between the clump and the ambient medium and on the grain sizes. For a low-density contrast of \\(100\\), e.g., \\(5\\,\\)nm silicate grains are completely destroyed while the survival fraction of \\(1\\,\\mu\\)m grains is \\(86\\,\\)per cent. For a high-density contrast of \\(1000\\), \\(95\\,\\)per cent of the \\(5\\,\\)nm grains survive while the survival fraction of \\(1\\,\\mu\\)m grains is \\(26\\,\\)per cent. Alternative clump sizes or dust materials (carbon) have non-negligible effects on the survival rate but have a lower impact compared to density contrast, magnetic field strength, and grain size.

The understanding of (sub-)millimetre polarisation has made a leap forward since high-resolution imaging with ALMA came available. Amongst other effects, self-scattering (i.e., scattering of thermal dust emission on other grains) is thought to be the origin of millimetre polarisation. This opens the first window to a direct measurement of dust grain sizes in regions of optically thick continuum emission as it can be found in protoplanetary disks and star-forming regions. However, the newly derived values of grain sizes are usually around \\({\\sim}100\\,\\mu\\)m and thus one order of magnitude smaller than those obtained from more indirect measurements as well as those expected from theory (\\({\\sim}1\\,\\)mm). We see the origin of this contradiction in the applied dust model of today's self-scattering simulations: a perfect compact sphere. The aim of this study is to test our hypothesis by investigating the impact of non-spherical grain shapes on the self-scattering signal. We apply discrete dipole approximation simulations to investigate the influence of the grain shape on self-scattering polarisation in three scenarios: an unpolarised and polarised incoming wave under a fixed as well as a varying incident polarisation angle. We find significant deviations of the resulting self-scattering polarisation when comparing non-spherical to spherical grains, in particular outside the Rayleigh regime, i.e. for >100\\(\\,\\mu\\)m size grains observed at \\(870\\,\\mu\\)m wavelength. Self-scattering by oblate grains produces higher polarisation degrees compared to spheres which challenges the interpretation of the origin of observed millimetre polarisation. A (nearly) perfect alignment of the non-spherical grains is required to account for the observed millimetre polarisation in protoplanetary disks. Our findings point towards a necessary re-evaluation of the dust grain sizes derived from (sub-)mm polarisation.

Context. While supernova remnants (SNRs) are observed to produce up to 1 M\\(_\\odot\\) of dust, the amount of dust destroyed by the forward shock (FS) is poorly constrained, raising the question whether they are net dust producers or destroyers. Aims. We aim to estimate the dust destruction efficiency of SNR FSs in a realistically turbulent interstellar medium (ISM) during their most destructive phase, and assess dust shielding by high density filaments during this period. Methods. We run 3D turbulence simulations for different turbulent Mach numbers (0-3) and average ISM densities (1-100 cm\\(^{-3}\\)) to resemble observations of the turbulent ISM. We then set off a supernova to trace its 3D magnetohydrodynamical evolution for 10 kyr. Finally, we run post-processing simulations to study the dust transport and destruction by the SNR FS, considering gas and plasma drag, kinetic and thermal sputtering, and grain-grain collisions, and either silicate or carbonaceous dust. Results. The dust destruction rate of the FS strongly depends on the average ISM density and turbulence strength, varying between 27-92% (0.85-11.0 M\\(_\\odot\\)) in the studied 10 kyr. Overall, dust is less efficiently destroyed in a low density medium (1 cm\\(^{-3}\\), 27-57%) than in intermediate (10 cm\\(^{-3}\\), 46-92%) and high densities (100 cm\\(^{-3}\\), 73-87%). The FS destroys 8-34% less dust in high Mach turbulence compared to a homogeneous medium. Furthermore, carbonaceous grains are more robust (up to 21% more) than silicates. Conclusions. Filaments can partly shield dust from destruction in the first 10 kyr, however, always more than 0.85 M\\(_\\odot\\) of dust is destroyed, making most SNRs dust sinks under the conditions explored in this work. The destruction efficiency of the SNRs with less than 1 M\\(_\\odot\\) of destroyed dust has not yet plateaued so that they are most likely also net dust destroyers by the end of their lifetime.