中文
相关论文

相关论文: Continuum emission around AGB stars at 1.2 mm

200 篇论文

Late asymptotic giant branch (AGB) and early post-AGB stars which are progenitors of planetary nebulae lose mass at extremely high rate, in what is termed a superwind. We show that the existence of this superwind during the post-AGB phase…

天体物理学 · 物理学 2007-05-23 Noam Soker , Amos Harpaz

Infrared Space Observatory (ISO) observations have shown that O-rich Asymptotic Giant Branch (AGB) stars exhibit crystalline silicate features in their spectra only if their mass-loss rate is higher than a certain threshold value. Usually,…

天体物理学 · 物理学 2009-01-06 F. Kemper , L. B. F. M. Waters , A. de Koter , A. G. G. M. Tielens

We examine the flow from asymptotic giant branch (AGB) stars when along a small solid angle the optical depth due to dust is very large. We consider two types of flows. In the first, small cool spots are formed on the surface of slowly…

天体物理学 · 物理学 2009-10-31 Noam Soker

We aim to constrain the dust mass and grain sizes in the interaction regions between the stellar winds and the ISM around asymptotic giant branch stars. By describing the dust in these regions, we aim to shed light on the role of low mass…

星系天体物理 · 物理学 2022-09-21 M. Maercker , T. Khouri , M. Mecina , E. De Beck

AGB stars are, together with supernovae, the main contributors of stellar dust to the interstellar medium (ISM). Dust grains formed by AGB stars are thought to be large. However, as dust nucleation and growth within their outflows are still…

太阳与恒星天体物理 · 物理学 2020-05-13 M. Van de Sande , C. Walsh , T. Danilovich

We examine the envelope properties of asymptotic giant branch (AGB) stars as they evolve on the upper AGB and during the early post-AGB phase. Due to the high mass loss rate, the envelope mass decreases by more than an order of magnitude.…

天体物理学 · 物理学 2009-10-31 Noam Soker , Amos Harpaz

Over two decades ago, a prominent, mysterious emission band peaking at ~20.1 micrometer was serendipitously detected in four preplanetary nebulae (PPNe; also known as "protoplanetary nebulae"). So far, this spectral feature, designated as…

太阳与恒星天体物理 · 物理学 2016-07-06 Ajay Mishra , Aigen Li , B. W. Jiang

The AKARI and Spitzer satellites provided an unique opportunity to observe a variety of stars, which are considered as departing from the Asymptotic Giant Branch (AGB) and have started their post-AGB evolution recently. Most of these stars…

太阳与恒星天体物理 · 物理学 2009-04-28 D. Engels , P. García-Lario , F. Bunzel , D. A. García-Hernández , J. V. Perea-Calderón

To study the effect of metallicity on the mass-loss rate of asymptotic giant branch (AGB) stars, we have conducted mid-infrared photometric measurements of such stars in the Sagittarius (Sgr dSph) and Fornax dwarf spheroidal galaxies with…

As part of a reanalysis of Galactic Asymptotic Giant Branch stars (hereafter AGB stars) at infrared wavelengths, we discuss here two samples (the first of carbon-rich stars, the second of S stars) for which photometry in the near- and…

天体物理学 · 物理学 2009-06-25 R. Guandalini , M. Busso , M. Cardinali

The heavy mass loss observed in evolved asymptotic giant branch stars is usually attributed to a two-step process: atmospheric levitation by pulsation-induced shock waves, followed by radiative acceleration of newly formed dust grains.…

太阳与恒星天体物理 · 物理学 2017-11-08 S. Bladh , C. Paladini , S. Höfner , B. Aringer

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…

天体物理学 · 物理学 2014-10-13 Jacco Th. van Loon , Maria-Rosa L. Cioni , Albert A. Zijlstra , Cecile Loup

Low- and intermediate-mass stars go through a period of intense mass-loss at the end of their lives in a phase known as the asymptotic giant branch (AGB). During the AGB a significant fraction of their initial mass is expelled in a stellar…

太阳与恒星天体物理 · 物理学 2015-05-13 T. Khouri , L. B. F. M. Waters , A. de Koter , L. Decin , M. Min , B. L. de Vries , R. Lombaert , N. L. J. Cox

We calculated theoretical evolutionary sequences of asymptotic giant branch (AGB) stars, including formation and evolution of dust grains in their circumstellar envelope. By considering stellar populations of the Large Magellanic Cloud…

太阳与恒星天体物理 · 物理学 2016-08-10 F. Dell'Agli , P. Ventura , R. Schneider , M. Di Criscienzo , D. A. García-Hernández , C. Rossi , E. Brocato

Convection and mass loss by stellar winds are two dynamical processes that shape asymptotic giant branch (AGB) stars and their evolution. Observations and earlier 3D models indicate that giant convection cells cause high-contrast surface…

太阳与恒星天体物理 · 物理学 2023-01-30 Bernd Freytag , Susanne Höfner

Mass loss is a fundamental, observationally well-established feature of AGB stars but many aspects of this process still remain to be understood. To date, self-consistent dynamical models of dust-driven winds reproducing the observed…

太阳与恒星天体物理 · 物理学 2010-11-10 H. Olofsson , S. Ramstedt , S. Sacuto , M. Maercker , S. Höfner , F. Kerschbaum

The material lost through stellar winds of Asymptotic Giant Branch (AGB) stars is one of the main contributors to the chemical enrichment of galaxies. The general hypothesis of the mass loss mechanism of AGB winds is a combination of…

太阳与恒星天体物理 · 物理学 2018-09-26 Jels Boulangier , Nicola Clementel , Allard Jan van Marle , Leen Decin , Alex de Koter

We study the asymptotic giant branch (AGB) evolution of stars with masses between $1~M_{\odot} - 8.5~M_{\odot}$. We focus on stars with a solar chemical composition, which allows us to interpret evolved stars in the Galaxy. We present a…

太阳与恒星天体物理 · 物理学 2018-02-14 P. Ventura , A. Karakas , F. Dell'Agli , D. A. García-Hernández , L. Guzman-Ramirez

Context: Mass loss plays a dominant role in the evolution of low mass stars while they are on the Asymptotic Giant Branch (AGB). The gas and dust ejected during this phase are a major source in the mass budget of the interstellar medium.…

天体物理学 · 物理学 2009-11-11 L. Decin , S. Hony , A. de Koter , K. Justtanont , A. G. G. M. Tielens , L. B. F. M. Waters

During their evolution, Asymptotic Giant Branch (AGB) stars experience a high mass-loss which leads to the formation of a Circumstellar Envelope (CSE) of dust and gas. The mass-loss process is the most important phenomenon during this…

太阳与恒星天体物理 · 物理学 2015-05-14 D. Ladjal , K. Justtanont , M. A. T. Groenewegen , J. A. D. L. Blommaert , C. Waelkens , M. J. Barlow