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Low and intermediate mass stars lose a significant fraction of their mass through a dust-driven wind during the Asymptotic Giant Branch (AGB) phase. Recent studies show that winds from late-type stars are far from being smooth. Mass-loss…

Astrophysics · Physics 2009-11-13 L. Decin , S. Hony , A. de Koter , G. Molenberghs , S. Dehaes , F. Markwick-Kemper

We present low spectral resolution molecular interferometric observations at 1.2 mm obtained with the Combined Array for Research in Millimetre-wave Astronomy (CARMA) towards the C-rich AGB star IRC+10216. We have mapped the emission of…

We report the results of a multi-epoch survey of water maser observations at 22.2 GHz with the Medicina radiotelescope from 44 bright rimmed clouds (BRCs) of the northern hemisphere identified by Sugitani et al. (1989) as potential sites of…

Astrophysics · Physics 2009-11-11 R. Valdettaro , F. Palla , J. Brand , R. Cesaroni

We have searched for the SiO J=1--0 v= 1 and 2 maser lines at ~ 43 GHz in 277 2MASS/MSX/IRAS sources off the Galactic plane (|b|> 3 deg), which resulted in 119 (112 new) detections. Among the new detections, are two very faint objects with…

Aims. Red supergiants (RSGs) are among the most luminous of all stars, easily detectable in external galaxies, and may ideally serve as kinematic tracers of Galactic structure. Some RSGs are surrounded by circumstellar envelopes detectable…

Astrophysics of Galaxies · Physics 2015-06-04 L. Verheyen , M. Messineo , K. M. Menten

We present radio and mm continuum observations of the Galactic center taken with the VLA and ALMA at 44 and 226 GHz, respectively. We detect radio and mm emission from IRS 3, lying ~4.5" NW of Sgr A*, with a spectrum that is consistent with…

Astrophysics of Galaxies · Physics 2017-03-15 F. Yusef-Zadeh , M. Wardle , W. Cotton , R. Schödel , M. J. Royster , D. A. Roberts , D. Kunneriath

High resolution spectra of 110 selected red giant stars in the globular cluster M15 (NGC 7078) were obtained with Hectochelle at the MMT telescope in 2005 May, 2006 May, and 2006 October. Echelle orders containing Halpha and Ca H & K are…

Astrophysics · Physics 2009-11-13 Sz. Meszaros , A. K. Dupree , A. Szentgyorgyi

We revisit the relation between H2O maser detection rate and nuclear obscuration for a sample of 114 Seyfert galaxies, drawn from the CfA, 12um and IRAS F25/F60 catalogs. These sources have mid-infrared spectra from the Spitzer Space…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Michael Ramolla , Martin Haas , Vardha Nicola Bennert , Rolf Chini

The winds observed around asymptotic giant branch (AGB) stars are generally attributed to radiation pressure on dust, which is formed in the extended dynamical atmospheres of these pulsating, strongly convective stars. Current…

Solar and Stellar Astrophysics · Physics 2022-12-07 Susanne Höfner , Bernd Freytag

This paper describes the identification of Gaia counterparts of a sample of oxygen-rich AGB stars with OH maser emission as a first step towards the compilation of a general Gaia Catalogue of Galactic AGB stars. With this catalogue, tests…

Solar and Stellar Astrophysics · Physics 2025-06-04 Belén López Martí , Francisco M. Jiménez Esteban , Dieter Engels , Pedro García Lario

A search for the near-infrared water-ice absorption band was made in a number of very red OH/IR stars which are known to exhibit the 10um silicate absorption. As a by-product, accurate positions of these highly reddened objects are…

Astrophysics · Physics 2009-11-11 K. Justtanont , G. Olofsson , C. Dijkstra , A. W. Meyer

We present ALMA 870 micron (345 GHz) data for 49 high redshift (0.47<z<2.85), luminous (11.7 < log L(bol) (Lsun) < 14.2) radio-powerful AGN, obtained to constrain cool dust emission from starbursts concurrent with highly obscured…

Water maser emission at 22 GHz is a useful probe to study the transition between the nearly spherical mass-loss in the AGB to a collimated one in the post-AGB phase. In their turn, collimated jets in the post-AGB phase could determine the…

Solar and Stellar Astrophysics · Physics 2015-06-17 J. F. Gomez , J. R. Rizzo , O. Suarez , A. Palau , L. F. Miranda , M. A. Guerrero , G. Ramos-Larios , J. M. Torrelles

We present an empirical determination of the mass-loss rate as a function of stellar luminosity and effective temperature, for oxygen-rich dust-enshrouded Asymptotic Giant Branch stars and red supergiants. To this aim we obtained optical…

Astrophysics · Physics 2014-10-13 Jacco Th. van Loon , Maria-Rosa L. Cioni , Albert A. Zijlstra , Cecile Loup

We report the first detection of submillimeter water maser emission toward water-fountain nebulae, which are post-AGB stars that exhibit high-velocity water masers. Using APEX we found emission in the ortho-H2O (10_29-9_36) transition at…

Solar and Stellar Astrophysics · Physics 2015-06-18 D. Tafoya , R. Franco-Hernández , W. H. T. Vlemmings , A. F. Pérez-Sánchez , G. Garay

Aims: We have observed the 6030 and 6035 MHz transitions of OH in high-mass star-forming regions to obtain magnetic field estimates in both maser emission and absorption. Methods: Observations were taken with the Effelsberg 100 m telescope.…

Astrophysics · Physics 2009-11-11 Vincent L. Fish , Mark J. Reid , Karl M. Menten , Thushara Pillai

We analyse ALMA observations of the SO($J_K=6_5-5_4$) emission of the circumstellar envelope of oxygen-rich AGB star R Dor, probing distances between 20 and 100 au from the star where the nascent wind is building up. We give evidence for…

Solar and Stellar Astrophysics · Physics 2019-10-02 P. T. Nhung , D. T. Hoai , P. Tuan-Anh , P. Darriulat , P. N. Diep , N. T. Phuong , T. T. Thai

We present a study of MSX point sources in the Galactic bulge (|l| < 3 deg, 1 deg < |b| < 5 deg), observed at A, C, D and E-band (8 to 21 micron), with a total area ~ 48 deg^2. We discuss the nature of the MSX sources (mostly AGB stars),…

Astrophysics · Physics 2007-08-07 D. K. Ojha , A. Tej , M. Schultheis , A. Omont , F. Schuller

Widespread galactic winds emanate from the Large Magellanic Cloud (LMC), with the 30 Doradus starburst region generating the fastest and most concentrated gas flows. We report on the gas distribution, kinematics, and ionization conditions…

In the recent literature there has been some doubt as to the reliability of CO multi-transitional line observations as a mass-loss-rate estimator for AGB stars. Mass-loss rates for 10 intermediate- to high-mass-loss-rate AGB stars are…

Astrophysics · Physics 2015-05-13 Sofia Ramstedt , Fredrik L. Schoeier , Hans Olofsson , Andreas A. Lundgren