Related papers: IRAC Observations of M81
The luminosity functions at z < 4 - 5 suggest that most galaxies have a relatively low stellar mass (logM_star = 10) and a low dust attenuation (A_FUV = 1.0). The physical properties of these objects are quite homogeneous. We used an…
New low-resolution UV spectra of a sample of reddened OB stars in M31 were obtained with HST/STIS to study the wavelength dependence of interstellar extinction and the nature of the underlying dust grain populations. Extinction curves were…
Hubble Space Telescope imaging of 11 fields in M31 were reduced to color-magnitude diagrams. The fields were chosen to sample all galactocentric radii to 50 kpc. Assuming that the bulk of the sampled stellar populations are older than a few…
We examine the dust and gas properties of the nearby, barred galaxy M83, which is part of the Very Nearby Galaxy Survey. Using images from the PACS and SPIRE instruments of Herschel, we examine the dust temperature and dust mass surface…
We present several molecular line emission arcsec and subarcsec observations obtained with the Submillimeter Array (SMA) in the direction of the massive protostar IRAS 18162-2048, the exciting source of HH 80-81. The data clearly indicates…
Isolated HAEBE stars are believed to represent an intermediate stage of objects between young stellar objects surrounded by massive, optically thick, gaseous and dusty disks and Vega like stars surrounded by debris disks. The star AB Aur is…
Several properties of the M31 disk, namely: opacity, extinction law and gas-to-dust ratio are studied by means of optical and near-infrared photometry of ten globular clusters and galaxies seen through the disk. The individual extinctions…
Using ISO-ISOPHOT we carried out a survey of almost 150 stars to search for evidence of emission from dust orbiting young main sequence stars, both in clusters and isolated systems. Over half of the detections are new examples of dusty…
We report the detection of vertically extended far-ultraviolet (FUV) and near-UV emissions in an edge-on spiral galaxy NGC 891, which we interpret as being due to dust-scattered starlight. Three-dimensional radiative transfer models are…
The vertical distribution of dust in debris disks is sensitive to the number and size of large planetesimals dynamically stirring the disk, and is therefore well-suited for constraining the prevalence of otherwise unobservable Uranus and…
We report spectra obtained with the Spitzer Space Telescope in the wavelength range between 14 microns and 35 microns of 19 nearby main-sequence stars with infrared excesses. The six stars with strong dust emission show no recognizable…
(abridged) Debris disks around main sequence stars are produced by the erosion and evaporation of unseen parent bodies. AU Microscopii (GJ 803) is a compelling object to study in the context of disk evolution across different spectral…
We present deep HST/ACS observations of the G1 clump, a distinct stellar overdensity lying at ~30 kpc along the south-western major axis of M31 close to the G1 globular cluster (Ferguson et al. 2002). Our well-populated colour-magnitude…
Galactic dust constitutes approximately half of the elements more massive than helium produced in stellar nucleosynthesis. Notwithstanding the formation of dust grains in the dense, cool atmospheres of late-type stars, there still remain…
We continue the analysis of the dataset of our spectroscopic observation campaign of M31, by deriving simple stellar population properties (age metallicity and alpha-elements overabundance) from the measurement of Lick/IDS absorption line…
New optical and NIR K-band images of the inner 3 kpc region of the nearby Virgo spiral M100 (NGC 4321) display remarkable morphological changes with wavelength. While in the optical the light is dominated by a circumnuclear zone of enhanced…
The nearby dwarf galaxy NGC 3077 is known for its peculiar morphology, which includes numerous dust lanes and emission-line regions. The interstellar medium in this galaxy is subject to several perturbing factors. These are primarily the…
We present a model for the diffuse interstellar dust that explains the observed wavelength-dependence of extinction, emission, linear and circular polarisation of light. The model is set-up with a small number of parameters. It consists of…
Infrared dark clouds are massive, dense clouds seen in extinction against the IR Galactic background. Many of these objects appear to be on the verge of star and star cluster formation. Our aim is to understand the physical properties of…
We have performed new medium resolution spectroscopy, optical and near infrared photometry to monitor the variability of the AGB carbon star V 381 Lac. Our observations revealed rapid and deep changes in the spectrum and extreme variability…