We build a rigorous statistical framework to provide constraints on the chemical and dust evolution parameters for nearby late-type galaxies with a wide range of gas fractions ($3\%<f_g<94\%$). A Bayesian Monte Carlo Markov Chain framework provides statistical constraints on the parameters used in chemical evolution models. Nearly a million one-zone chemical and dust evolution models were compared to 340 galaxies. Relative probabilities were calculated from the $χ^2$ between data and models, marginalised over the different time steps, galaxy masses and star formation histories. We applied this method to find `best fitting' model parameters related to metallicity, and subsequently fix these metal parameters to study the dust parameters. For the metal parameters, a degeneracy was found between the choice of initial mass function, supernova metal yield tables and outflow prescription. For the dust parameters, the uncertainties on the best fit values are often large except for the fraction of metals available for grain growth, which is well constrained. We find a number of degeneracies between the dust parameters, limiting our ability to discriminate between chemical models using observations only. For example, we show that the low dust content of low-metallicity galaxies can be resolved by either reducing the supernova dust yields and/or including photo-fragmentation. We also show that supernova dust dominates the dust mass for low metallicity galaxies and grain growth dominates for high metallicity galaxies. The transition occurs around $12+\log({\rm O/H})=7.75$, which is lower than found in most studies in the literature.
The DUSTiNGS survey (DUST in Nearby Galaxies with Spitzer) is a 3.6 and 4.5 micron imaging survey of 50 nearby dwarf galaxies designed to identify dust-producing Asymptotic Giant Branch (AGB) stars and massive stars. Using two epochs, spaced approximately six months apart, we identify a total of 526 dusty variable AGB stars (sometimes called "extreme" or x-AGB stars; [3.6]-[4.5]>0.1 mag). Of these, 111 are in galaxies with [Fe/H] < -1.5 and 12 are in galaxies with [Fe/H] < -2.0, making them the most metal-poor dust-producing AGB stars known. We compare these identifications to those in the lit…
Cosmic dust grains are one of the fundamental ingredients of the interstellar medium (ISM). In spite of their small contribution to the total mass budget, dust grains play a significant role in the physical and chemical evolution of galaxies. Over the past decades, a plethora of multi-wavelength data, from UV to far-infrared, has increased substantially our knowledge on the dust properties of nearby galaxies. Nevertheless, one regime of the spectrum, the mm range, remains relatively unexplored. Thanks to the new, high-resolution data in the mm range observed with the NIKA2 instrument and our r…
The study of gas-dust interactions occurring in the interstellar medium of a galaxy is essential for understanding various physical processes taking place within it. A comparison of such events at different locations corresponding to diverse astrophysical environments provides more insight into the star-formation as well as dust destruction conditions and time-scales. We present a case study for two galaxies: NGC 3184 and NGC 7793, which are typical examples of a `grand design spiral' and a `flocculent spiral', respectively. We investigate the gas-dust correlations at various spatially resolve…
This article gives an overview of the constitution, physical conditions and observables of dust in the interstellar medium of nearby galaxies. We first review the macroscopic, spatial distribution of dust in these objects, and its consequence on our ability to study grain physics. We also discuss the possibility to use dust tracers as diagnostic tools. We then survey our current understanding of the microscopic, intrinsic properties of dust in different environments, derived from different observables: emission, extinction, polarization, depletions, over the whole electromagnetic spectrum. Fin…
Nearby resolved dwarf galaxies provide excellent opportunities for studying the dust-producing late stages of stellar evolution over a wide range of metallicity (-2.7 < [Fe/H] < -1.0). Here, we describe DUSTiNGS (DUST in Nearby Galaxies with Spitzer): a 3.6 and 4.5 micron post-cryogen Spitzer Space Telescope imaging survey of 50 dwarf galaxies within 1.5 Mpc that is designed to identify dust-producing Asymptotic Giant Branch (AGB) stars and massive stars. The survey includes 37 dwarf spheroidal, 8 dwarf irregular, and 5 transition-type galaxies. This near-complete sample allows for the buildin…
Extinction curves, especially those in the Milky Way (MW), the Large Magellanic Cloud (LMC), and the Small Magellanic Cloud (SMC), have provided us with a clue to the dust properties in the nearby Universe. We examine whether or not these extinction curves can be explained by well known dust evolution processes. We treat the dust production in stellar ejecta, destruction in supernova shocks, dust growth by accretion and coagulation, and dust disruption by shattering. To make a survey of the large parameter space possible, we simplify the treatment of the grain size distribution evolution by ad…
In order to examine their relation to the host galaxy, the extraplanar dust of six nearby galaxies are modeled, employing a three dimensional Monte Carlo radiative transfer code. The targets are from the highly-inclined galaxies that show dust-scattered ultraviolet halos, and the archival Galaxy Evolution Explorer FUV band images were fitted with the model. The observed images are in general well reproduced by two dust layers and one light-source layer, whose vertical and radial distributions have exponential profiles. We obtained several important physical parameters, such as star formation r…
Interstellar dust is a key physical ingredient of galaxies, obscuring star formation, regulating the heating and cooling of the gas, and building-up chemical complexity. In this manuscript, I give a wide review of interstellar dust properties and some of the modern techniques used to study it. I start with a general introduction presenting the main concepts, in molecular and solid-state physics, required to understand the contemporary literature on the subject. I then review the empirical evidence we currently use to constrain state-of-the-art dust models. Follows a long discussion about our c…
Pristine composition or size evolution: Can current dust models reproduce emissivities observed in nearby protostars?
Université Paris-Saclay（巴黎萨克雷大学）；Université Paris Cité（巴黎西岱大学）；CEA（法国原子能和替代能源委员会）；CNRS（法国国家科学研究中心）；AIM（天体物理学和分子动力学研究所）；Institute of Space Sciences (ICE), CSIC（空间科学研究所，西班牙高等科学研究委员会）；ICREA（加泰罗尼亚高级研究学院）；IRAP, CNRS, Université de Toulouse（天体物理与行星学研究所在，法国国家科学研究中心，图卢兹大学）；Institut d’Astrophysique Spatiale（天体物理研究所）；European Southern Observatory（欧洲南方天文台）
We examined variations in the 160/250 and 250/350 micron surface brightness ratios within 24 nearby (<30 Mpc) face-on spiral galaxies observed with the Herschel Space Observatory to identify the heating mechanisms for dust emitting at these wavelengths. The analysis consisted of both qualitative and quantitative comparisons of the 160/250 and 250/350 micron ratios to H alpha and 24 micron surface brightnesses, which trace the light from star forming regions, and 3.6 micron emission, which traces the light from the older stellar populations of the galaxies. We find broad variations in the heati…
(Aims) In this work, we predict the far-infrared polarisation signal emitted by non-spherical dust grains in nearby galaxies. We determine the angular resolution and sensitivity required to study the magnetic field configuration in these galaxies. (Methods) We post-process a set of Milky Way like galaxies from the Auriga project, assuming a dust mix consisting of spheroidal dust grains that are partially aligned with the model magnetic field. We constrain our dust model using Planck 353 GHz observations of the Milky Way. This model is then extrapolated to shorter wavelengths that cover the pea…
We combine dust, atomic (HI) and molecular (H$_{2}$) hydrogen mass measurements for 176 galaxies in the Herschel Reference Survey to investigate the effect of environment on the gas-to-dust mass ($M_{\rm gas}/M_{\rm dust}$) ratio of nearby galaxies. We find that, at fixed stellar mass, the average $M_{\rm gas}/M_{\rm dust}$ ratio varies by no more than a factor of $\sim$2 when moving from field to cluster galaxies, with Virgo galaxies being slightly more dust rich (per unit of gas) than isolated systems. Remarkably, once the molecular and atomic hydrogen phases are investigated separately, we …
The low density interstellar medium (ISM) close to the Sun and inside of the heliosphere provides a unique laboratory for studying interstellar dust grains. Grain characteristics in the nearby ISM are obtained from observations of interstellar gas and dust inside of the heliosphere and the interstellar gas towards nearby stars. Comparison between the gas composition and solar abundances suggests that grains are dominated by olivines and possibly some form of iron oxide. Measurements of the interstellar Ne/O ratio by the Interstellar Boundary Explorer spacecraft indicate that a high fraction of…
We study spatially resolved properties (on spatial scales of $\sim 1-2$ kpc out to at least $3$ effective radii) of the stars, dust, and gas in ten nearby spiral galaxies. The properties of the stellar population and dust are derived by fitting the spatially resolved spectral energy distribution (SED) with more than 20 photometric bands ranging from far-ultraviolet to far-infrared. Our newly developed software piXedfit performs point spread function matching of images, pixel binning, and models the stellar light, dust attenuation, dust emission, and emission from a dusty torus heated by an act…
We present the results from an analysis of deep Herschel Space Observatory observations of six nearby dwarf galaxies known to host galactic-scale winds. The superior far-infrared sensitivity and angular resolution of Herschel have allowed detection of cold circumgalactic dust features beyond the stellar components of the host galaxies traced by Spitzer 4.5 $μ$m images. Comparisons of these cold dust features with ancillary data reveal an imperfect spatial correlation with the ionized gas and warm dust wind components. We find that typically $\sim$10-20\% of the total dust mass in these galaxie…
Methods. We have modelled a sample of ~800 nearby galaxies, spanning a wide range of metallicity, gas fraction, specific star formation rate and Hubble stage. We have derived the dust properties of each object from its spectral energy distribution. Through an additional level of analysis, we have inferred the timescales of dust condensation in core-collapse supernova ejecta, grain growth in cold clouds and dust destruction by shock waves. Throughout this paper, we have adopted a hierarchical Bayesian approach, resulting in a single large probability distribution of all the parameters of all th…
Star-forming galaxies are rich reservoirs of dust, both warm and cold. But the cold dust emission is faint alongside the relatively bright and ubiquitous warm dust emission. Recently, evidence for a very cold dust component has also been revealed via millimeter/submillimeter photometry of some galaxies. This component, despite being the most massive of the three dust components in star-forming galaxies, is by virtue of its very low temperature, faint and hard to detect together with the relatively bright emission from warmer dust. Here we analyze the dust content of a carefully selected sample…
We aim to characterize the relationship between dust properties. We also aim to provide equations to estimate accurate dust properties from limited observational datasets. We assemble a sample of 1,630 nearby (z<0.1) galaxies-over a large range of Mstar, SFR - with multi-wavelength observations available from wise, iras, planck and/or SCUBA. The characterization of dust emission comes from SED fitting using Draine & Li dust models, which we parametrize using two components (warm and cold ). The subsample of these galaxies with global measurements of CO and/or HI are used to explore the molecul…
The survey for DUST In Nearby Galaxies with Spitzer (DUSTiNGS) has identified hundreds of candidate dust-producing Asymptotic Giant Branch (AGB) stars in several nearby metal-poor galaxies. We have obtained multi-epoch follow-up observations for these candidates with the Spitzer Space Telescope and measured their infrared (IR) lightcurves. This has allowed us to confirm their AGB nature and investigate pulsation behavior at very low metallicity. We have obtained high-confidence pulsation periods for 88 sources in seven galaxies. We have confirmed DUSTiNGS variable star candidates with a 20% su…
We examine the dust geometry and Lyα scattering in the galaxies of the Lyman Alpha Reference Sample (LARS), a set of 14 nearby (0.02 < $z$ < 0.2) Lyα emitting and starbursting systems with Hubble Space Telescope Lyα, Hα, and Hβ imaging. We find that the global dust properties determined by line ratios are consistent with other studies, with some of the LARS galaxies exhibiting clumpy dust media while others of them show significantly lower Lyα emission compared to their Balmer decrement. With the LARS imaging, we present Lyα/Hα and Hα/Hβ maps with spatial resolutions as low as $\sim$ 40 pc, an…
We study the dust properties of 192 nearby galaxies from the JINGLE survey using photometric data in the 22-850micron range. We derive the total dust mass, temperature T and emissivity index beta of the galaxies through the fitting of their spectral energy distribution (SED) using a single modified black-body model (SMBB). We apply a hierarchical Bayesian approach that reduces the known degeneracy between T and beta. Applying the hierarchical approach, the strength of the T-beta anti-correlation is reduced from a Pearson correlation coefficient R=-0.79 to R=-0.52. For the JINGLE galaxies we me…
The dust mass absorption coefficient, $κ_{d}$, is the conversion function used to infer physical dust masses from observations of dust emission. However, it is notoriously poorly constrained, and it is highly uncertain how it varies, either between or within galaxies. Here we present the results of a proof-of concept study, using the DustPedia data for two nearby face-on spiral galaxies M74 (NGC 628) and M83 (NGC 5236), to create the first ever maps of $κ_{d}$ in galaxies. We determine $κ_{d}$ using an empirical method that exploits the fact that the dust-to-metals ratio of the interstellar me…
We report the first uniform and systematic study of dust and molecular gas in nearby molecular clouds. We use surveys of dust extinction and emission to determine the opacity and map the distribution of the dust within a dozen local clouds in order to derive a uniform set of basic cloud properties. We find: 1) the average dust opacity $\langleκ_{d,353}\rangle = 0.8\ {\rm cm^{2}\, g^{-1}}$ with variations of a factor of $\sim$ 2 between clouds, 2) cloud PDFs are exquisitely described by steeply falling power-laws with a narrow range of slope, and 3) a tight $M_{\rm GMC} \sim R_{\rm GMC}^2$ scal…
A fraction of the early-type galaxy population hosts a prominent dust lane. Methods to quantify the dust content of these systems based on optical imaging data usually yield dust masses which are an order of magnitude lower than dust masses derived from the observed FIR emission. High-quality optical data from the Next Generation Virgo cluster Survey (NGVS) and FIR/submm observations from the Herschel Virgo Cluster Survey (HeViCS) allow us to revisit previous methods to determine the dust content in galaxies and explore new ones. We aim to derive the dust mass in NGC 4370 from both optical and…
Comparing the Nebular and Stellar Dust Attenuation Curves in Nearby Star-Forming Galaxies
Korea Astronomy and Space Science Institute (KASI)（韩国天文与空间科学研究院）；Department of Earth Science Education, Kyungpook National University（庆北国立大学地球科学教育系）；Department of Astronomy and Space Science, Chungnam National University（忠南国立大学天文学与空间科学系）；Astronomy Program, Department of Physics and Astronomy, Seoul National University（首尔国立大学物理天文学系天文学项目）；SNU Astronomy Research Center, Seoul National University（首尔国立大学天文研究中心）；Institute for Data Innovation in Science, Seoul National University（首尔国立大学数据创新科学研究院）
Mapping Dust Attenuation at Kiloparsec Scales. IV. A Dust-model Interpretation of Attenuation Curves in Nearby Galaxies
Tsinghua University（清华大学）；INAF–Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；National Astronomical Observatories, Chinese Academy of Sciences（中国科学院国家天文台）；The Chinese University of Hong Kong（香港中文大学）
We investigate the relationship between the dust-to-metals ratio (D/M) and the local interstellar medium environment at ~2 kpc resolution in five nearby galaxies: IC342, M31, M33, M101, and NGC628. A modified blackbody model with a broken power-law emissivity is used to model the dust emission from 100 to 500 um observed by Herschel. We utilize the metallicity gradient derived from auroral line measurements in HII regions whenever possible. Both archival and new CO rotational line and HI 21 cm maps are adopted to calculate gas surface density, including new wide field CO and HI maps for IC342 …
We present a study of the dust-to-gas ratios in five nearby galaxies NGC 628 (M74), NGC 6503, NGC 7793, UGC 5139 (Holmberg I), and UGC 4305 (Holmberg II). Using Hubble Space Telescope broad band WFC3/UVIS UV and optical images from the Treasury program LEGUS (Legacy ExtraGalactic UV Survey) combined with archival HST/ACS data, we correct thousands of individual stars for extinction across these five galaxies using an isochrone-matching (reddening-free Q) method. We generate extinction maps for each galaxy from the individual stellar extinctions using both adaptive and fixed resolution techniqu…
The dust extinction curves toward individual sight lines in M33 are derived for the first time with a sample of reddened O-type and B-type supergiants obtained from the LGGS. The observed photometric data are obtained from the LGGS, PS1 Survey, UKIRT, PHATTER Survey, GALEX, Swift/UVOT and XMM-SUSS. We combine the intrinsic spectral energy distributions (SEDs) obtained from the ATLAS9 and Tlusty stellar model atmosphere extinguished by the model extinction curves from the silicate-graphite dust model to construct model SEDs. The extinction traces are distributed along the arms in M33, and the d…
Dust emission at 8 micron has been extensively calibrated as an indicator of current star formation rate for galaxies and ~kpc-size regions within galaxies. Yet, the exact link between the 8 micron emission and the young stellar populations in galaxies is still under question, as dust grains can be stochastically heated also by older field stars. In order to investigate this link, we have combined mid-infrared images from the Spitzer Space Telescope with a published star cluster candidates catalog for the Local Group galaxy M33. M33 is sufficiently close that the Spitzer's 8 micron images reso…
We present and analyze spatially-resolved maps for the observed $V$- and $g$-band to 3.6$μ$m flux ratios and the inferred dust extinction values, $A_V$, for a sample of 257 nearby NGC and IC galaxies. Flux ratio maps are constructed using PSF-matched mosaics of SDSS $g$- and $r$-band images and Spitzer/IRAC 3.6$μ$m mosaics, with all pixels contaminated by foreground stars or background objects masked out. By applying the $β_V$ method (Tamura et al. 2009, 2010), which was recently calibrated as a function of redshift and morphological type by Kim, Jansen, & Windhorst (2017), dust extinction map…
We study spatially resolved scaling relations among stars, dust, and gas in ten nearby spiral galaxies. In a preceding paper Abdurro'uf et al. (2022), we have derived spatially resolved properties of the stellar population and dust by panchromatic spectral energy distribution (SED) fitting using piXedfit. Now, we investigate resolved star formation ($Σ_{\rm H_{2}}$--$Σ_{\rm SFR}$--$Σ_{*}$) and dust scaling relations. While the relations with all sub-galactic regions of the galaxies are reasonably tight ($σ\lesssim 0.3$ dex), we find that most of the scaling relations exhibit galaxy-to-galaxy v…
We compare the spectral energy distributions (SEDs) and inferred physical properties for simulated and observed galaxies at low redshift. We exploit UV-submillimetre mock fluxes of ~7000 z=0 galaxies from the EAGLE suite of cosmological simulations, derived using the radiative transfer code SKIRT. We compare these to ~800 observed galaxies in the UV-submillimetre range, from the DustPedia sample of nearby galaxies. To derive global properties, we apply the SED fitting code CIGALE consistently to both data sets, using the same set of ~80 million models. The results of this comparison reveal ove…
We present arcsecond-scale observations of the active galactic nuclei (AGNs) of seven nearby Seyfert galaxies observed from the Stratospheric Observatory For Infrared Astronomy (SOFIA) using the 31.5 and 37.1 um filters of the Faint Object infraRed CAmera for the SOFIA Telescope (FORCAST). We isolate unresolved emission from the torus and find extended diffuse emission in six 37.1 um residual images in our sample. Using Spitzer/IRS spectra, we determine the dominant mid-infrared (MIR) extended emission source and attribute it to dust in the narrow line region (NLR) or star formation. We compar…
JWST reveals the diversity of nuclear obscuring dust in nearby AGN: nuclear isolation of MIRI/MRS datacubes and continuum spectral fitting
Instituto de Radioastrononomía y Astrofísica (IRyA), Universidad Nacional Autónoma de México（墨西哥国立自治大学射电天文学与天体物理研究所）；Centro de Astrobiología (CAB), CSIC-INTA（西班牙国家航空航天技术研究所/西班牙高等科学研究理事会天体生物学中心）；Department of Physics & Astronomy, University of South Carolina（南卡罗来纳大学物理与天文系）；Kavli Institute for Particle Astrophysics & Cosmology (KIPAC), Stanford University（斯坦福大学卡弗里粒子天体物理与宇宙学研究所）；Instituto de Astrofśica de Canarias（加那利群岛天体物理研究所）；Departamento de Astrofísica, Universidad de La Laguna（拉帕尔马大学天体物理学系）
Aims: Mapping the interstellar medium in 3D provides a wealth of insights into its inner working. The Milky Way is the only galaxy for which detailed 3D mapping can be achieved in principle. In this paper, we reconstruct the dust density in and around the local super-bubble. Methods: The combined data from surveys such as Gaia, 2MASS, PANSTARRS, and ALLWISE provide the necessary information to make detailed maps of the interstellar medium in our surrounding. To this end, we used variational inference and Gaussian processes to model the dust extinction density, exploiting its intrinsic correlat…
Physical conditions of the interstellar medium in galaxies are closely linked to the ambient radiation field and the heating of dust grains. In order to characterize dust properties in galaxies over a wide range of physical conditions, we present here the radial surface brightness profiles of the entire sample of 61 galaxies from Key Insights into Nearby Galaxies: Far-Infrared Survey with Herschel (KINGFISH). The main goal of our work is the characterization of the grain emissivities, dust temperatures, and interstellar radiation fields responsible for heating the dust. After fitting the dust …
We present the results of surveying [CI] $^3P_1-^3P_0$, $^{12}$CO $J=4-3$, and 630 $μ$m dust continuum emission for 36 nearby ultra/luminous infrared galaxies (U/LIRGs) using the Band 8 receiver mounted on the Atacama Compact Array (ACA) of the Atacama Large Millimeter/submillimeter Array. We describe the survey, observations, data reduction, and results; the main results are as follows. (i) We confirmed that [CI] $^3P_1-^3P_0$ has a linear relationship with both the $^{12}$CO $J=4-3$and 630 $μ$m continuum. (ii) In NGC 6052 and NGC 7679, $^{12}$CO $J=4-3$ was detected but [CI] $^3P_1-^3P_0$ wa…
Aims: Highly resolved maps of the local Galactic dust are an important ingredient for sky emission models. In nearly the whole electromagnetic spectrum one can see imprints of dust, many of which originate from dust clouds within 300pc. Having a detailed 3D reconstruction of these local dust clouds enables detailed studies, helps to quantify the impact on other observables and is a milestone necessary to enable larger reconstructions, as every sightline for more distant objects will pass through the local dust. Methods: To infer the dust density we use parallax and absorption estimates publish…
Dust has long been identified as a barrier to measuring inherent galaxy properties. However, the link between dust and attenuation is not straightforward and depends on both the amount of dust and its distribution. Herschel imaging of nearby galaxies undertaken as part of the KINGFISH project allows us to map the dust as seen in emission with unprecedented sensitivity and ~1 kpc resolution. We present here new optical integral field unit spectroscopy for eight of these galaxies that provides complementary 100-200 pc scale maps of the dust attenuation through observation of the reddening in bot…
Dusty, neutral outflows and inflows are a common feature of nearby star-forming galaxies. We characterize these flows in eight galaxies -- mostly AGN -- selected for their widespread NaI D signatures from the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7). This survey employs deep, wide field-of-view integral field spectroscopy at moderate spectral resolution (R=7000 at NaI D). We significantly expand the sample of sightlines in external galaxies in which the spatially-resolved relationship has been studied between cool, neutral gas properties -- N(NaI), Weq(NaI D) -- and du…
How do active galactic nuclei with low optical luminosities produce powerful radio emission? Recent studies of active galactic nuclei with moderate radio and low optical luminosities (Fanaroff & Riley class I, FR I) searching for broad nuclear emission lines in polarized light, as predicted by some active galactic nucleus unification models, have found heterogeneous results. These models typically consist of a central engine surrounded by a torus of discrete dusty clouds. These clouds would absorb and scatter optical emission, blocking broad nuclear emission lines, and reradiate in mid-infrare…
We have examined polycyclic aromatic hydrocarbon (PAH) excitation in a sample of 25 nearby face-on spiral galaxies using the ratio of mid-infrared PAH emission to dust mass. Within 11 of the galaxies, we found that the PAH excitation was straightforwardly linked to ultraviolet or mid-infrared star formation tracers, which, along with other results studying the relation of PAH emission to star formation, indicates that the PAHs are most strongly excited in dusty shells around the star forming regions. Within another 5 galaxies, the PAH emission is enhanced around star forming regions only at sp…
An unbiased search for debris discs around nearby Sun-like stars is reported. Thirteen G-dwarfs at 12-15 parsecs distance were searched at 850 $\umu$m wavelength, and a disc is confirmed around HD 30495. The estimated dust mass is 0.008 M$_{\oplus}$ with a net limit $\la 0.0025$ M$_{\oplus}$ for the average disc of the other stars. The results suggest there is not a large missed population of substantial cold discs around Sun-like stars -- HD 30495 is a bright rather than unusually cool disc, and may belong to a few hundred Myr-old population of greater dust luminosity. The far-infared and mil…
Most radio galaxies are hosted by giant gas-poor ellipticals, but some contain significant amounts of dust, which is likely to be of external origin. In order to characterize the mid-IR properties of two of the most nearby and brightest merger-remnant radio galaxies of the Southern hemisphere, NGC 1316 (Fornax A) and NGC 612 (PKS 0131-36), we used observations with the Wide-field Infrared Survey Explorer (WISE) at wavelengths of 3.4, 4.6, 12 and 22 micron and Spitzer mid-infrared spectra. By applying a resolution-enhancement technique, new WISE images were produced at angular resolutions rangi…
Winds driven by stellar feedback are an essential part of the galactic ecosystem and are the main mechanism through which low-mass galaxies regulate their star formation. These winds are generally observed to be multi-phase with detections of entrained neutral and molecular gas. They are also thought to enrich the circum-galactic medium around galaxies with metals and dust. This ejected dust encodes information about the integrated star formation and outflow history of the galaxy. It is therefore, important to understand how much dust is entrained and driven out of the disc by galactic winds. …
We have explored the capabilities of dust extinction and $γ$ rays to probe the properties of the interstellar medium in the nearby anti-centre region. We have jointly modelled the $γ$-ray intensity and the stellar reddening, E(B-V) as a combination of H$_{\rm I}$-bright, CO-bright, and ionised gas components. The complementary information from dust reddening and $γ$ rays is used to reveal the dark gas not seen, or poorly traced, by H$_{\rm I}$, free-free, and $^{12}$CO emissions. We compare the total gas column densities, $N_{\rm{H}}$, derived from the $γ$ rays and stellar reddening with those…
