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Related papers: The 21 micron and 30 micron circumstellar dust fea…

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Using the Canada-France-Hawaii Telescope we have obtained deep high-resolution CCD images in V and I of a 28'x28' field in the outer disk of M 31 at ~ 116' from the center along the major axis to the south-west, and covering a range of…

We present high resolution BV images of 12 edge-on spiral galaxies observed with the WIYN 3.5-m telescope. These images were obtained to search for extraplanar (|z| > 0.4 kpc) absorbing dust structures similar to those previously found in…

Astrophysics · Physics 2009-10-31 J. Christopher Howk , Blair D. Savage

We examine the infrared properties of five low surface brightness galaxies (LSBGs) and compare them with related but higher surface brightness galaxies, using Spitzer Space Telescope images and spectra. All the LSBGs are detected in the 3.6…

Stars on the asymptotic giant branch (AGB) produce dust in their circumstellar shells. The nature of the dust-forming environment is influenced by the evolution of the stars, in terms of both chemistry and density, leading to an evolution…

Astrophysics · Physics 2009-11-13 Angela Speck , Grant Thompson , Anne Hofmeister

We measure the extent of 100 micron galactic emission in two independent galaxy samples using the IRAS 100 micron Sky Survey images and constrain the distribution of dust at large ($\ltsim$30 kpc) radii. The first sample consists of 90…

Astrophysics · Physics 2009-10-30 Amy E. Nelson , Dennis Zaritsky , Roc M. Cutri

Dust in the host galaxies of gamma-ray bursts (GRBs) dims and reddens their afterglow spectra. Knowledge of the nature of this dust is crucial for correcting for extinction, providing clues to the nature of GRB progenitors, and probing the…

Astrophysics · Physics 2009-11-11 Shilun Chen , Aigen Li , Daming Wei

Circumstellar disks are characteristic for star formation and vanish during the first few Myr of stellar evolution. During this time planets are believed to form in the dense midplane by growth, sedimentation and aggregation of dust.…

Solar and Stellar Astrophysics · Physics 2015-06-05 D. Madlener , S. Wolf , A. Dutrey , S. Guilloteau

We present Spitzer/IRS spectra of 31 TTS and IRAM/1.3mm observations for 34 low- and intermediate-mass stars in the Cep OB2 region. Including our previously published data, we analyze 56 TTS and the 3 intermediate-mass stars with silicate…

A major unsolved problem in galaxy evolution is the early appearance of massive quiescent galaxies that no longer actively form stars only $ \sim 1$ billion years after the Big Bang. Their high stellar masses and extremely compact structure…

The dependence of stellar molecular bands on the metallicity is studied using infrared L-band spectra of AGB stars (both carbon-rich and oxygen-rich) and M-type supergiants in the Large and Small Magellanic Clouds (LMC and SMC) and in the…

We present optical high-resolution spectra of a sample of sixteen post-AGB stars and IRC +10216. Of the post-AGB stars, ten show C2 Phillips and Swan and CN Red System absorption, one CH+ emission, one CH+ absorption, and four without any…

Astrophysics · Physics 2016-08-30 Eric J. Bakker , Ewine F. van Dishoeck , L. B. F. M. Waters , Ton Schoenmaker

We present ISO photometric and spectroscopic observations of a sample of 57 bright Asymptotic Giant Branch stars and red supergiants in the Large Magellanic Cloud, selected on the basis of IRAS colours indicative of high mass-loss rates.…

Dust growth is often indirectly inferred observationally in star-forming environments, theoretically predicted to produce mm-sized particles in circumstellar discs, and also presumably witnessed by the predecessors of the terrestrial…

Earth and Planetary Astrophysics · Physics 2025-03-19 Matthäus Schulik , Bertram Bitsch , Anders Johansen , Michiel Lambrechts

We present observational evidences that dust in the circumnuclear region of AGNs has different properties than in the Galactic diffuse interstellar medium. By comparing the reddening of optical and infrared broad lines and the X-ray…

Astrophysics · Physics 2009-10-31 R. Maiolino , A. Marconi , M. Salvati , G. Risaliti , P. Severgnini , F. La Franca , L. Vanzi

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…

Astrophysics · Physics 2011-02-11 E. Xilouris , P. Alton , J. Alikakos , K. Xilouris , P. Boumis , C. Goudis

It is currently accepted that Hot-Bottom-Burning (HBB) in intermediate-mass asymptotic giant branch (AGB) stars prevents the formation of C~stars. Nevertheless, we present in this paper the results of some detailed evolutionary calculations…

Astrophysics · Physics 2007-05-23 Cheryl Frost , Robert Cannon , John Lattanzio , Peter Wood , Manuel Forestini

Since the epoch of cosmic star formation peak at $z \sim 2$, most of it is obscured in high mass galaxies, while in low mass galaxies the radiation escapes unobstructed. During the reionization epoch, the presence of evolved, dust obscured…

Astrophysics of Galaxies · Physics 2020-10-21 J. H. Barbosa-Santos , Gastão B. Lima Neto , Amancio C. S. Friaça

We present ground-based 3 micron spectra of obscured Asymptotic Giant Branch (AGB) stars in the Magellanic Clouds (MCs). We identify the carbon stars on the basis of the 3.1 micron absorption by HCN and C2H2 molecules. We show evidence for…

Astrophysics · Physics 2009-10-26 Jacco Th. van Loon , Albert A. Zijlstra , M. A. T. Groenewegen

Dust radiative transfer models are presented for all 374 AGB stars candidates in one of the fields observed by the new VISTA survey of the Magellanic Clouds (VMC). Mass-loss rates, luminosities and a classification of C- and O-rich stars…

We present the second of two papers concerning the origin and evolution of local early-type galaxies exhibiting dust features. We use optical and radio data to examine the nature of active galactic nucleus (AGN) activity in these objects,…