Evolution of dust attenuation in star-forming galaxies with UV slope, stellar mass, and redshift out to $z \sim 5$
Nicolaus Copernicus University（尼古拉·哥白尼大学）；University of Edinburgh（爱丁堡大学）；National Centre for Nuclear Research（国家核研究中心）；Adam Mickiewicz University（亚当·密茨凯维奇大学）
J. V. Wijesekera, M. P. Koprowski, J. S. Dunlop, K. Lisiecki, D. J. McLeod, R. J. McLure, M. J. Michałowski, M. Solar
备注：
13 pages, 8 figures and 5 tables, submitted to A&A
Aims. We derive a dependence of the IRX on UV slope $β$, stellar mass $M_\ast$, and redshift out to $z \simeq 5$, and establish consistent functional relations that can be used for correcting the UV/optical-selected galaxy samples for the effects of dust absorption.
Methods. This work is based on a $K$-band selected sample of $\sim 10^5$ star-forming galaxies detected in the UDS and COSMOS fields. Quiescent sources and known starbursts are removed, and the IR luminosities are established through stacking in FIR {\it Herschel} and JCMT maps. UV slopes are found from SED fits and stacked IRX values are derived by taking the median of individual IRX measurements in bins of $β$, $M_\ast$ and redshift.
Results. While our best-fit IRX-$β$ relation is consistent with a Calzetti-like attenuation curve at $β\gtrsim -1$, at bluer values the IRX seems to increase with redshift due to different mass-completeness limits imposed. When deriving the IRX-$β$ relation in stellar-mass bins, a systematic trend is found, where the effective slope of the attenuation law becomes progressively shallower with increasing mass. We incorporate this into the IRX-$β$ relation through the slope of the underlying reddening law, $dA_{1600}/dβ$, being a quadratic function of $\log(M_\ast/{\rm M_\odot})$. Expressing IRX as a function of the stellar mass we find a tight correlation, with IRX rising monotonically with mass but exhibiting a clear high-mass turnover at $z\lesssim 2-3$, consistent with suppressed cold-gas accretion and dust growth in massive systems.
Dust attenuation in star-forming spiral galaxies affects stars and gas in different ways due to local variations in dust geometry. We present spatially resolved measurements of dust attenuation for a sample of 232 such star-forming spiral galaxies, derived from spectra acquired by the SDSS-IV MaNGA survey. The dust attenuation affecting the stellar populations of these galaxies (obtained using full spectrum stellar population fitting methods) is compared with the dust attenuation in the gas (derived from the Balmer decrement). Both of these attenuation measures increase for local regions of ga…
Studying the UV dust attenuation, as well as its relation to other galaxy parameters such as the stellar mass, plays an important role in multi-wavelength research. This work relates the dust attenuation to the stellar mass of star forming galaxies, and its evolution with redshift. A sample of galaxies with an estimate of the dust attenuation computed from the infrared excess was used. The dust attenuation vs. stellar mass data, separated in redshift bins, was modelled by a single parameter linear function, assuming a nonzero constant apparent dust attenuation for low mass galaxies. But the or…
Analysing a large representative sample of local galaxies (8707), we find that the variation in the shape of their dust attenuation curves is driven primarily by their structure, i.e., distribution of stars (and dust) within them. The attenuation curve for spheroid dominated galaxies, as compared to the disc dominated ones, is nearly twice as steep. Both structural types cover distinct ranges of attenuation slope values. Similar findings are reflected in the case of star-forming and passive galaxies. Spheroids and passive galaxies witness minimal attenuation in the optical compared to UV wavel…
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）
Dust attenuation is a crucial but highly uncertain parameter that hampers the determination of intrinsic galaxy properties, such as stellar masses, star formation rates and star formation histories. The shape of the dust attenuation law is not expected to be uniform between galaxies, nor within a galaxy. Our DustKING project was introduced at the first BINA workshop in 2016 and aims to study the variations of dust attenuation curves in nearby galaxies. At the second BINA workshop in 2018, I presented the results of our pilot study for the spiral galaxy NGC628. We find that the average attenuat…
One of the most common methods for inferring galaxy attenuation curves is via spectral energy distribution (SED) modeling, where the dust attenuation properties are modeled simultaneously with other galaxy physical properties. In this paper, we assess the ability of SED modeling to infer these dust attenuation curves from broadband photometry, and suggest a new flexible model that greatly improves the accuracy of attenuation curve derivations. To do this, we fit mock SEDs generated from the Simba cosmological simulation with the Prospector SED fitting code. We consider the impact of the common…
We present the Empirical Dust Attenuation (EDA) framework -- a flexible prescription for assigning realistic dust attenuation to simulated galaxies based on their physical properties. We use the EDA to forward model synthetic observations for three state-of-the-art large-scale cosmological hydrodynamical simulations: SIMBA, IllustrisTNG, and EAGLE. We then compare the optical and UV color-magnitude relations, $(g-r) - M_r$ and $(FUV-NUV)-M_r$, of the simulations to a $M_r < -20$ and UV complete SDSS galaxy sample using likelihood-free inference. Without dust, none of the simulations match obse…
We examine the evolution of dust attenuation curve using a sample of 9504 disk star-forming galaxies (SFGs) selected from the CANDELS and 3D-HST surveys and a new technique relying on the fact that disk SFGs of similar stellar masses at the same cosmic epoch are statistically identical in stellar populations. We attribute the discrepancy in median magnitude between face-on (b/a>0.7) and edge-on (b/a<=0.4) subsamples solely to dust attenuation, and obtain the average attenuation in the rest-frame UV and optical as functions of stellar mass and redshift out to z=2.5. Our results show that the at…
We develop a method to estimate the dust attenuation curve of galaxies from full spectral fitting of their optical spectra. Motivated from previous studies, we separate the small-scale features from the large-scale spectral shape, by performing a moving average method to both the observed spectrum and the simple stellar population model spectra. The intrinsic dust-free model spectrum is then derived by fitting the observed ratio of the small-scale to large-scale (S/L) components with the S/L ratios of the SSP models. The selective dust attenuation curve is then determined by comparing the obse…
Dust emission from high-redshift galaxies gives us a clue to the origin and evolution of dust in the early Universe. Previous studies have shown that different sources of dust (stellar dust production and dust growth in dense clouds) predict different ultraviolet (UV) extinction curves for galaxies at $z\sim 7$ but that the observed attenuation curves depend strongly on the geometry of dust and star distributions. Thus, we perform radiative transfer calculations under the dust-stars geometries computed by a cosmological hydrodynamic simulation (IllustrisTNG). This serves to investigate the dus…
Understanding the properties and physical mechanisms that shape dust attenuation curves in galaxies is one of the fundamental questions of extragalactic astrophysics, with a great practical significance for deriving the physical properties of galaxies, such as the star formation rate and stellar mass. Attenuation curves result from a combination of dust grain properties, dust content, and the spatial arrangement of dust and different populations of stars. In this review we assess the current state of the field, paying particular attention to the importance of extinction curves as the building …
The spatial distribution of dust in galaxies affects the global attenuation, and hence inferred properties, of galaxies. We trace the spatial distribution of dust in five fields (at 0.6-0.9 kpc scale) of M31 by comparing optical attenuation with the total dust mass distribution. We measure the attenuation from the Balmer decrement using Integral Field Spectroscopy and the dust mass from Herschel far-IR observations. Our results show that M31's dust attenuation closely follows a foreground screen model, contrary to what was previously found in other nearby galaxies. By smoothing the M31 data we…
We study the drivers of the scatter in the IRX-beta relation using 23,000 low-redshift galaxies from the GALEX-SDSS-WISE Legacy Catalog 2 (GSWLC-2). For each galaxy we derive, using CIGALE and the SED+LIR fitting technique, the slope of the dust attenuation curve and the strength of the UV bump, plus many other galaxy parameters. We find that the IRX-beta scatter is driven entirely by a wide range of attenuation curves - primarily their slopes. Once the slope and the UV bump are fixed, the scatter in the IRX-beta vanishes. The question of the IRX-beta scatter is the direct manifestation of a m…
We analyze the distribution of rest-frame U-V and V-J colors for star-forming galaxies at 0.5 < z < 2.5. Using stellar population synthesis, stochastic star formation histories, and a simple prescription for the dust attenuation that accounts for the shape and inclination of galaxies, we construct a model for the distribution of galaxy colors. With only two free parameters, this model is able to reproduce the observed galaxy colors as a function of redshift and stellar mass remarkably well. Our analysis suggests that the wide range of dust attenuation values measured for star-forming galaxies …
Dust has been detected in high-redshift ($z>5$) galaxies but its origin is still being debated. Dust production in high-redshift galaxies could be dominated by stellar production or by accretion (dust growth) in the interstellar medium. Previous studies have shown that these two dust sources predict different grain size distributions, which lead to significantly different extinction curves. In this paper, we investigate how the difference in the extinction curves affects the dust attenuation properties of galaxies by performing radiative transfer calculations. To examine the major effects of t…
We investigate the relationship between dust attenuation and stellar mass ($M_*$) in star-forming galaxies over cosmic time. For this analysis, we compare measurements from the MOSFIRE Deep Evolution Field (MOSDEF) survey at $z\sim2.3$ and the Sloan Digital Sky Survey (SDSS) at $z\sim0$, augmenting the latter optical dataset with both UV Galaxy Evolution Explorer (GALEX) and mid-infrared Wide-field Infrared Survey Explorer (WISE) photometry from the GALEX-SDSS-WISE Catalog. We quantify dust attenuation using both spectroscopic measurements of H$α$ and H$β$ emission lines, and photometric measu…
(Abridged) We aim to study the evolution of dust attenuation in galaxies selected in the IR in the redshift range in which they are known to dominate the star formation activity in the universe. The comparison with other measurements of dust attenuation in samples selected using different criteria will give us a global picture of the attenuation at work in star-forming galaxies and its evolution with redshift. Using multiple filters of IRC instrument, we selected more than 4000 galaxies from their rest-frame emission at 8 microns, from z~0.2 to 2$. We built SEDs from the rest-frame UV to the f…
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）
We study dust attenuation curves of 230,000 individual galaxies in the local universe, ranging from quiescent to intensely star-forming systems, using GALEX, SDSS, and WISE photometry calibrated on Herschel-ATLAS. We use a new method of constraining SED fits with infrared luminosity (SED+LIR fitting), and parameterized attenuation curves determined with the CIGALE SED fitting code. Attenuation curve slopes and UV bump strengths are reasonably well constrained independently from one another. We find that $A_λ/A_V$ attenuation curves exhibit a very wide range of slopes that are on average as ste…
The newest generation of integral field unit spectrographs brings three-dimensional mapping of nearby galaxies one step closer. While the focus up to this point was mostly on stars and ionised gas, it is also possible to look at dust in a new, more complete way. Using MUSE science verification observations of NGC 5626, we map the interstellar matter in this dusty lenticular. We use the resolving power of MUSE to measure the optical attenuation with a spectral resolution of 6.25 Å, at physical scales of 0.1-1 kpc. The integrated attenuation curve of NGC 5626 shows a smooth, slightly steeper tha…
There is now ample evidence that dust is already present in abundance at high z. However, given the faintness of distant galaxies in the optical and the NIR, datasets are still limited and how the dust affects the emerging radiation of galaxies at very high redshift is not yet fully understood. Using the ALPINE survey, our objective is to quantify the dust attenuation properties in galaxies at z=4.4-5.5, and in particular the shape of their attenuation curve. Using the CIGALE code, we model the stellar populations and their interaction with the dust in order to measure some of the physical pro…
Do spatial distributions of dust grains in galaxies have typical forms, as do spatial distributions of stars? We investigate whether or not the distributions resemble uniform foreground screens, as commonly assumed by the high-redshift galaxy community. We use rest-frame infrared, ultraviolet, and H$α$ line luminosities of dust-poor and dusty galaxies at z ~ 0 and z ~ 1 to compare measured H$α$ escape fractions with those predicted by the Calzetti attenuation formula. The predictions, based on UV escape fractions, overestimate the measured H$α$ escape fractions for all samples. The interpretat…
The attenuation of starlight by dust in galactic environments is investigated through models of radiative transfer in a spherical, clumpy ISM. Extinction properties for MW, LMC, and SMC dust types are considered. It is illustrated that the attenuation curves are primarily determined by the wavelength dependence of absorption rather than by the underlying extinction (absorption+scattering) curve. Attenuation curves consistent with the "Calzetti attenuation curve" are found by assuming the silicate-carbonaceous dust model for the MW, but with the 2175A absorption bump suppressed or absent. The d…
We present a novel approach to measure the attenuation curves of 485 individual star-forming galaxies with M$_*$ $>$ 10$^{10}$ M$_{\odot}$ based on deep optical spectra from the VLT/VIMOS LEGA-C survey and multi-band photometry in the COSMOS field. Most importantly, we find that the attenuation curves in the rest-frame $3000-4500$A range are typically almost twice as steep as the Milky Way, LMC, SMC, and Calzetti attenuation curves, which is in agreement with recent studies of the integrated light of present-day galaxies. The attenuation at $4500$A and the slope strongly correlate with the gal…
We investigate the attenuation law in $z\sim 6$ quasars by combining cosmological zoom-in hydrodynamical simulations of quasar host galaxies, with multi-frequency radiative transfer calculations. We consider several dust models differing in terms of grain size distributions, dust mass and chemical composition, and compare the resulting synthetic Spectral Energy Distributions (SEDs) with data from bright, early quasars. We show that only dust models with grain size distributions in which small grains ($a < 0.1~μ$m, corresponding to $\approx 60\%$ of the total dust mass) are selectively removed …
The use of ultraviolet (UV) emission as a tracer of galaxy star-formation rate (SFR) is hampered by dust obscuration. The empirical relationship between UV slope, $β$, and the ratio between far-infrared and UV luminosity, IRX, is commonly employed to account for obscured UV emission. We present a simple model that explores the physical origin of variations in the IRX - $β$ dust attenuation relation. A relative increase in FUV attenuation compared to NUV attenuation and an increasing stellar population age cause variations towards red UV slopes for a fixed IRX. Dust geometry effects (turbulence…
We study the relative dust attenuation-inclination relation in 78,721 nearby galaxies using the axis ratio dependence of optical-NIR colour, as measured by the Sloan Digital Sky Survey (SDSS), the Two Micron All Sky Survey (2MASS), and the Wide-field Infrared Survey Explorer (WISE). In order to avoid to the greatest extent possible attenuation-driven biases, we carefully select galaxies using dust attenuation-independent near- and mid-IR luminosities and colours. Relative u-band attenuation between face-on and edge-on disc galaxies along the star forming main sequence varies from ~0.55 mag up …
In this paper, we provide a physical model for the origin of variations in the shapes and bump strengths of dust attenuation laws in galaxies by combining a large suite of cosmological "zoom-in" galaxy formation simulations with 3D Monte Carlo dust radiative transfer calculations. We model galaxies over 3 orders of magnitude in stellar mass, ranging from Milky Way like systems through massive galaxies at high-redshift. Critically, for these calculations we employ a constant underlying dust extinction law in all cases, and examine how the role of geometry and radiative transfer effects impact t…
As a science verification study of the newly released AKARI/FIS Faint Source Catalog ver.1, this paper discusses the different levels of dust attenuation toward stellar light and nebular emission lines within local star-forming galaxies at 0.02<z<0.10. By constructing an updated version of the AKARI-SDSS-GALEX matched galaxy catalog (with >2,000 sources), we compare the dust attenuation levels toward stellar light (from L(IR)/L(UV) ratio) and nebular emission lines (from H-alpha/H-beta ratio). We find that there is a clear trend that more massive galaxies tend to have higher "extra" attenuatio…
In this work we investigate the far-UV to NIR shape of the dust attenuation curve of a sample of IR selected dust obscured (U)LIRGs at z$\sim$2. The spectral energy distributions (SEDs) are fitted with CIGALE, a physically-motivated spectral synthesis model based on energy balance. Its flexibility allows us to test a wide range of different analytical prescriptions for the dust attenuation curve, including the well-known Calzetti and Charlot & Fall curves, and modified versions of them. The attenuation curves computed under the assumption of our reference double power-law model are in very goo…
We present the first measurements of the shape of the far-ultraviolet (far-UV; lambda=950-1500 A) dust attenuation curve at high redshift (z~3). Our analysis employs rest-frame UV spectra of 933 galaxies at z~3, 121 of which have very deep spectroscopic observations (>7 hrs) at lambda=850-1300 A, with the Low Resolution Imaging Spectrograph on the Keck Telescope. By using an iterative approach in which we calculate the ratios of composite spectra in different bins of continuum color excess, E(B-V), we derive a dust curve that implies a lower attenuation in the far-UV for a given E(B-V) than th…
The dust attenuation for a sample of $\sim$10000 local ($z\lesssim0.1$) star forming galaxies is constrained as a function of their physical properties. We utilize aperture-matched multi-wavelength data available from the Galaxy Evolution Explorer (GALEX) and the Sloan Digital Sky Survey (SDSS) to ensure that regions of comparable size in each galaxy are being analyzed. We follow the method of Calzetti et al. (1994) and characterize the dust attenuation through the UV power-law index, $β$, and the dust optical depth, which is quantified using the difference in Balmer emission line optical dept…
We have investigated effects of dust attenuation on quasar luminosity functions using a semi-analytic galaxy formation model combined with a large cosmological N-body simulation. We estimate the dust attenuation of quasars self-consistently with that of galaxies by considering the dust in their host bulges. We find that the luminosity of the bright quasars is strongly dimmed by the dust attenuation, about 2 mag in the B-band. Assuming the empirical bolometric corrections for active galactic nuclei (AGNs) by Marconi et al., we find that this dust attenuation is too strong to explain the B-band …
We compile a sample of about 157,000 spaxels from the Mapping Nearby Galaxies at the Apache Point Observatory survey to derive the average dust attenuation curve for subgalactic star-forming regions of local star-forming galaxies (SFGs) in the optical wavelength, following the method of \cite{Calzetti1994}. We obtain a $D_n(4000)$-independent average attenuation curve for spaxels with $1.1\leq D_n(4000)<1.3$, which is similar to the one derived from either local starbursts or normal SFGs. We examine whether and how the shape of the average attenuation curve changes with several local and globa…
Dust attenuation shapes the spectral energy distribution of galaxies. It is particularly true for dusty galaxies in which stars experience a heavy attenuation. The combination of UV-to-IR photometry with the spectroscopic measurement of the H$α$ recombination line helps to quantify dust attenuation of the whole stellar population and its wavelength dependence. We selected an IR complete sample of galaxies in the COSMOS 3D-HST CANDELS field detected with the Herschel satellite with a signal to noise ratio larger than five. Optical to NIR photometry is available as well as NIR spectroscopy for e…
We use observed optical to near infrared spectral energy distributions (SEDs) of 266 galaxies in the COSMOS survey to derive the wavelength dependence of the dust attenuation at high redshift. All of the galaxies have spectroscopic redshifts in the range z = 2 to 6.5. The presence of the CIV absorption feature, indicating that the rest-frame UV-optical SED is dominated by OB stars, is used to select objects for which the intrinsic, unattenuated spectrum has a well-established shape. Comparison of this intrinsic spectrum with the observed broadband photometric SED then permits derivation of the…
Simulations of Dust Content and Attenuation in $z=5-15$ Galaxies
University of Florida（佛罗里达大学）；The University of Texas at Austin（德克萨斯大学奥斯汀分校）；Niels Bohr Institute, University of Copenhagen（哥本哈根大学尼尔斯·玻尔研究所）；University of California, Santa Barbara（加州大学圣塔芭芭拉分校）；Harvard-Smithsonian Center for Astrophysics（哈佛-史密森天体物理中心）
We use a sample of $78,340$ star-forming galaxies at $z\simeq 0.04-0.1$ from the SDSS DR8 survey to calculate the average nebular dust attenuation curve and its variation with the physical properties of galaxies. Using the first four low-order Balmer emission lines (H$α$, H$β$, H$γ$, H$δ$) detected in the composite spectrum of all galaxies in the sample, we derive a nebular attenuation curve in the range of $0.41\,μ$m to $0.66\,μ$m that has a similar shape and normalization to that of the Galactic extinction curve (Milky Way curve), the SMC curve and the nebular attenuation curve derived recen…
We calibrated a technique to measure dust attenuation in star-forming galaxies. The technique utilizes the stellar-wind lines in Wolf-Rayet stars, which are widely observed in galaxy spectra. The He II 1640 and 4686 features are recombination lines whose ratio is largely determined by atomic physics. Therefore they can serve as a stellar dust probe in the same way as the Balmer lines are used as a nebular probe. We measured the strength of the He II 1640 line in 97 Wolf-Rayet stars in the Galaxy and the Large Magellanic Cloud. The reddening corrected fluxes follow a tight correlation with a fi…
We characterize the influence that inclination has on the shape and normalization in average dust attenuation curves derived from a sample of ~10,000 local star-forming galaxies. To do this we utilize aperture-matched multi-wavelength data from the Galaxy Evolution Explorer, the Sloan Digital Sky Survey, the United Kingdom Infrared Telescope, and the Two Micron All-Sky Survey. We separate our sample into groups according to axial ratio (b/a) and obtain an estimate of their average total-to-selective attenuation $k(λ)$. The attenuation curves are found to be shallower at UV wavelengths with inc…
We explore the possibility and practical limitations of using a three-line approach to measure both the slope and normalization of the dust attenuation law in individual galaxies. To do this, we focus on a sample of eleven galaxies with existing ground-based Balmer H$α$ and H$β$ measurements from slit spectra, plus space-based grism constraints on Paschen-$β$. When accounting for observational uncertainties, we show that one galaxy has a well-constrained dust law slope and normalization in the range expected from theoretical arguments; this galaxy therefore provides an example of what may be p…
Non-Parametric Attenuation Curves in Local Star-Forming Galaxies: Geometry Effect, Dust Evolution, and ISS
Institute for Astronomy, School of Physics, Zhejiang University（浙江大学物理学院天体物理研究所）；Center for Cosmology and Computational Astrophysics, Zhejiang University（浙江大学宇宙学与计算天体物理中心）；Purple Mountain Observatory（中国科学院紫金山天文台）；Shanghai Astronomical Observatory, Chinese Academy of Sciences（中国科学院上海天文台）；Key Lab for Astrophysics（天体物理重点实验室）；School of Astronomy and Space Sciences, University of Chinese Academy of Sciences（中国科学院大学天文与空间科学学院）；Sterrenkundig Observatorium, Universiteit Gent（根特大学天文台）；College of Physics, Hebei Normal University（河北师范大学物理学院）；Shijiazhuang Key Laboratory of Astronomy and Space Science / Guoshoujing Institute of Astronomy, Hebei Normal University（河北师范大学石家庄天文与空间科学重点实验室/郭守敬天文研究所）；Hebei Key Laboratory of Photophysics Research and Application（河北省光物理研究与应用重点实验室）
Dust attenuation of an inclined galaxy can cause additional asymmetries in observations, even if the galaxy has a perfectly symmetric structure. {Taking advantage of the integral field spectroscopic data observed by the SDSS-IV MaNGA survey, we investigate the asymmetries of the emission-line and continuum maps of star-forming disk galaxies.} We define new parameters, $A_a$ and $A_b$, to estimate the asymmetries of a galaxy about its major and minor axes, respectively. Comparing $A_a$ and $A_b$ in different inclination bins, we attempt to detect the asymmetries caused by dust. For the continuu…
We built a 8um selected sample of galaxies in the NEP-AKARI field by defining 4 redshift bins with the four AKARI bands at 11, 15, 18 and 24 microns (0.15<z<0.49, 0.75<z<1.34, 1.34<z<1.7 and 1.7<z<2.05) . Our sample contains 4079 sources, 599 are securely detected with Herschel/PACS. Also adding ultraviolet (UV) data from GALEX, we fit the spectral energy distributions using the physically motivated code CIGALE to extract the star formation rate, stellar mass, dust attenuation and the AGN contribution to the total infrared luminosity (L_{IR}). We discuss the impact of the adopted attenuation c…
A diverse range of dust attenuation laws is found in star-forming galaxies. In particular, Tress et al. (2018) studied the SHARDS survey to constrain the NUV bump strength (B) and the total-to selective ratio (Rv) of 1,753 star-forming galaxies in the GOODS-N field at 1.5<z<3. We revisit here this sample to assess the implications and possible causes of the correlation found between Rv and B. The UVJ bicolour plot and main sequence of star formation are scrutinised to look for clues into the observed trend. The standard boundary between quiescent and star-forming galaxies is preserved when tak…
We use \Pab\ (1282~nm) observations from the Hubble Space Telescope ($\HST$) G141 grism to study the star-formation and dust attenuation properties of a sample of 29 low-redshift ($z < 0.287$) galaxies in the CANDELS Ly$α$ Emission at Reionization (CLEAR) survey. We first compare the nebular attenuation from $\Pab/\Ha$ with the stellar attenuation inferred from the spectral energy distribution, finding that the galaxies in our sample are consistent with an average ratio of the continuum attenuation to the nebular gas of 0.44, but with a large amount of excess scatter beyond the observational u…
We present the results of a study investigating the dust attenuation law at $z\simeq 5$, based on synthetic spectral energy distributions (SEDs) calculated for a sample of N=498 galaxies drawn from the First Billion Years (FiBY) simulation project. The simulated galaxies at $z\simeq 5$, which have M$_{1500} \leq -18.0$ and $7.5 \leq \rm{log(M/M}_{\odot}\rm{)} \leq 10.2$, display a mass-dependent $α$-enhancement, with a median value of $[α/\rm{Fe}]_{z=5}~\simeq~4~\times~[α/\rm{Fe}]_{Z_{\odot}}$. The median Fe/H ratio of the simulated galaxies is $0.14\pm0.05$ which, even including the effects o…
We update the spectral modeling code MAGPHYS to include a 2175Å absorption feature in its UV-to-near-IR dust attenuation prescription. This allows us to determine the strength of this feature and the shape of the dust attenuation curve in ~5000 star-forming galaxies at 0.1<z<3 in the COSMOS field. We find that a 2175Å absorption feature of ~1/3 the strength of that in the Milky Way is required for models to minimize residuals. We characterize the total effective dust attenuation curves as a function of several galaxy properties and find that the UV slopes of the attenuation curve for COSMOS ga…
We compare the infrared excess (IRX) and Balmer decrement (${\rm Hα/Hβ}$) as dust attenuation indicators in relation to other galaxy parameters using a sample of $\sim$32 000 local star-forming galaxies (SFGs) carefully selected from SDSS, GALEX and WISE. While at fixed ${\rm Hα/Hβ}$, IRX turns out to be independent on galaxy stellar mass, the Balmer decrement does show a strong mass dependence at fixed IRX. We find the discrepancy, parameterized by the color excess ratio $R_{\rm EBV} \equiv E(B-V)_{\rm IRX}/E(B-V)_{\rm Hα/Hβ}$, is not dependent on the gas-phase metallicity and axial ratio but…
