Related papers: Hubble Tarantula Treasury Project. IV. The extinct…
We present optical and ultraviolet (UV) photometry and spectra of the very nearby and highly reddened supernova (SN) 2014J in M82 obtained with the Swift Ultra-Violet/Optical Telescope (UVOT). Comparison of the UVOT grism spectra of…
To investigate the distribution of dust in Sb and Sc galaxies we have analyzed near-infrared and optical surface photometry for an unbiased sample of 37 galaxies. Since light in the $K$-band is very little affected by extinction by dust,…
Using the "standard pair" technique of paring stars of almost nil and high extinction but otherwise of almost identical stellar parameters from the SDSS, and combing the SDSS, GALEX, 2MASS and WISE photometry ranging from the far UV to the…
A sample of 109 type Ia supernovae (SNe Ia) with recession velocity < 30,000 km s^{-1}, is compiled from published SNe Ia light curves to explore the expansion rate of the local Universe. Based on the color parameter delta C_{12} and the…
The empirical reddening function for starburst galaxies generated by Calzetti and her co-workers has proven very successful, and is now used widely in the observational literature. Despite its success, however, the physical basis for this…
We discuss the deep galaxy counts from the Hubble Deep Field (HDF) imaging survey. At faint magnitudes, the slope of the differential number-magnitude relation is flatter than 0.2 in all four HDF bandpasses. In the ultraviolet, a…
Scattering and absorption of light by a homogeneous distribution of intergalactic large dust grains has been proposed as an alternative, non-cosmological explanation for the faintness of Type Ia supernovae at $z\s im 0.5$. We investigate…
By combining optical and near-IR observations from the Hubble Space Telescope with NIR photometry from the Spitzer Space Telescope it is possible to measure the rest-frame UV-optical colours of galaxies at z=4-8. The UV-optical spectral…
We present CCD imaging observations of early-type galaxies with dark lanes obtained with the Southern African Large Telescope (SALT) during its performance-verification phase. We derive the extinction law by the extragalactic dust in the…
The VLT-FLAMES Tarantula Survey has observed hundreds of O-type stars in the 30 Doradus region of the Large Magellanic Cloud (LMC). We study the properties of 105 apparently single O-type dwarfs. To determine stellar and wind parameters, we…
We identify a vertical extension of the red clump stars in the color magnitude diagram (CMD) of a section of the Large Magellanic Cloud (LMC). After subtracting the principal red clump component, we find a peak in the residual stellar…
Existing observations are consistent with rich clusters of galaxies having no dust on $\simgt$ Mpc scales, while galaxy groups most probably do have dust distributed over $\lesssim$ Mpc scales. Dust in groups accounts for the observed…
The extinction laws at 7um and 15um are derived for more than 120 sightlines in the inner Galactic plane based on the ISOGAL survey data and the near-infrared data from DENIS and 2MASS. The tracers are the ISOGAL point sources with…
We investigate the multiplicity properties of 408 B-type stars observed in the 30 Doradus region of the Large Magellanic Cloud with multi-epoch spectroscopy from the VLT-FLAMES Tarantula Survey (VFTS). We use a cross-correlation method to…
The characterisation of the extinction curve in the near infrared (NIR) is fundamental to analyse the structure and stellar population of the Galactic centre (GC), whose analysis is hampered by the extreme interstellar extinction ($A_V\sim…
We examine the relationship between circumnebular extinction and core mass for sets of [O III]-bright planetary nebulae (PNe) in the Large Magellanic Cloud and M31. We confirm that for PNe within one magnitude of the Planetary Nebula…
Aims. We analyze the multiplicity properties of the massive O-type star population. With 360 O-type stars, this is the largest homogeneous sample of massive stars analyzed to date. Methods. We use multi-epoch spectroscopy and variability…
Accurate interpretation of observations relies on the interstellar dust extinction law, which also serves as a powerful diagnostic for probing dust properties. In this study, we investigate the multi-wavelength extinction law of the…
There is a longstanding discrepancy between the observed Galactic classical nova rate of $\sim 10$ yr$^{-1}$ and the predicted rate from Galactic models of $\sim 30$--50 yr$^{-1}$. One explanation for this discrepancy is that many novae are…
Using photometric and spectroscopic data of Supernova (SN) 2012cu, a fairly reddened type Ia supernova, we derived its color excess curves and probed the dust extinction in its host galaxy, NGC 4772. In order to derive the extinction as a…