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Understanding planet formation requires to discern how dust grows in protoplanetary disks. An important parameter to measure in disks is the maximum dust grain size present. This is usually estimated through measurements of the dust opacity…

Most radiative transfer models assume that dust in spiral galaxies is distributed exponentially. In this paper our goal is to verify this assumption by analysing the two-dimensional large-scale distribution of dust in galaxies from the…

We present 7-mm continuum observations of 14 low-mass pre-main-sequence stars in the Taurus-Auriga star-forming region obtained with the Very Large Array with ~1.5" resolution and ~0.3 mJy rms sensitivity. For 10 objects, the circumstellar…

Astrophysics · Physics 2009-11-11 J. Rodmann , Th. Henning , C. J. Chandler , L. G. Mundy , D. J. Wilner

Deep HI observations of the outer parts of disc galaxies demonstrate the frequent presence of extended, well-developed spiral arms far beyond the optical radius. To understand the nature and the origin of such outer spiral structure, we…

Astrophysics of Galaxies · Physics 2015-05-19 S. A. Khoperskov , G. Bertin

We analyse a high-resolution, fully cosmological, hydrodynamical disc galaxy simulation, to study the source of the double-exponential light profiles seen in many stellar discs, and the effects of stellar radial migration upon the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Patricia Sanchez-Blazquez , Stephanie Courty , Brad Gibson , Christopher Brook

The statistics of the fundamental bulge and disk parameters of galaxies and their relation to the Hubble sequence were investigated by an analysis of optical and near-infrared observations of 86 face-on spiral galaxies. The availability of…

Astrophysics · Physics 2009-05-29 Roelof S. de Jong

Gravitational lensing of a quasar by a spiral galaxy should often be accompanied by damped Lyman-alpha absorption and dust extinction due to the intervening gaseous disk. In nearly edge-on configurations, the surface mass density of the gas…

Astrophysics · Physics 2009-10-30 Matthias Bartelmann , Abraham Loeb

We present the first nonparametric morphological analysis of a set of spiral galaxies from UV to submm wavelengths. Our study is based on high-quality multi-wavelength imaging for nine well-resolved spiral galaxies from the DustPedia…

Deep HST broad-band images taken with ACS and WFPC2 of the giant ($\sim 1000$ AU diameter) dark silhouette proplyd 114-426 in the Orion Nebula show that this system is tilted, asymmetric, warped and photoevaporated. The exquisite angular…

Solar and Stellar Astrophysics · Physics 2016-03-02 Anna Miotello , Massimo Robberto , Marco A. C. Potenza , Luca Ricci

Much of our understanding of dark matter halos comes from the assumption that the mass-to-light ratio (M/L) of spiral disks is constant. The best way to test this hypothesis is to measure the disk surface mass density directly via the…

Astrophysics of Galaxies · Physics 2014-11-20 Kimberly A. Herrmann , Robin Ciardullo

The dust in nearby galaxies absorbs a fraction of the UV-optical-near-infrared radiation produced by stars. This energy is consequently re-emitted in the infrared. We investigate the portion of the stellar radiation absorbed by spiral…

ISO observations at 200 micron have modified our view of the dust component in spiral galaxies. For a sample of seven resolved spirals we have retrieved a mean temperature of 20K, about 10K lower than previous estimates based on IRAS data…

Astrophysics · Physics 2007-05-23 Simone Bianchi , Paul B. Alton , Jonathan I. Davies

We studied a sample of 58 edge-on spiral galaxies at redshifts $z \sim 1$ selected in the Hubble Ultra Deep Field. For all galaxies we analyzed the 2D brightness distributions in the $V_{606}$ and $i_{775}$ filters and measured the radial…

Astrophysics of Galaxies · Physics 2020-01-08 V. P. Reshetnikov , P. A. Usachev , S. S. Savchenko

Galaxies are thought to grow through accretion; as less massive galaxies are disrupted and merge over time, their debris results in diffuse, clumpy stellar halos enveloping the central galaxy. Here we present a study of the variation in the…

Astrophysics of Galaxies · Physics 2016-10-19 Allison Merritt , Pieter van Dokkum , Roberto Abraham , Jielai Zhang

We present high-resolution, optical images (BVI + Halpha) of the multiphase interstellar medium (ISM) in the thick disks of the edge-on spiral galaxies NGC 4013 and NGC 4302. Our images from the Hubble Space Telescope, Large Binocular…

Dust determines the temperature structure of protoplanetary disks. However, dust temperature determinations almost invariably rely on a complex modeling of the Spectral Energy Distribution. We attempt a direct determination of the…

Solar and Stellar Astrophysics · Physics 2016-01-27 S. Guilloteau , V. Piétu , E. Chapillon , E. Di Folco , A. Dutrey , T. Henning , D. Semenov , T. Birnstiel , N. Grosso

We study the radial distribution of the temperature of the warm dust and gas-to-dust mass ratios in a sample of 22 spiral galaxies. The heating capabilities of the diffuse interstellar radiation field (ISRF), based on Desert et al. model,…

Astrophysics · Physics 2009-10-30 Y. D. Mayya , T. N. Rengarajan

The outer regions of disk galaxies show a drop-off in optical and Halpha emission, suggesting a star formation threshold radius, assumed to owe to a critical surface density below which star formation does not take place. Signs of…

Astrophysics · Physics 2009-11-13 Stephanie J. Bush , T. J. Cox , Lars Hernquist , David Thilker , Joshua D. Younger

We investigate high resolution imaging polarimetry of HD 169142 taken in the R' and I' bands with the SPHERE/ZIMPOL instrument for an accurate quantitative measurement of the radiation scattered by the circumstellar disk. We observe a…

Earth and Planetary Astrophysics · Physics 2021-11-10 C. Tschudi , H. M. Schmid

We review the most recent evidence for the amazing properties of the density distribution of dark matter around spiral galaxies. Their rotation curves, coadded according to the galaxy luminosity, conform to an universal profile which can be…

Astrophysics · Physics 2007-05-23 P. Salucci , A. Borriello