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Related papers: Model Atmospheres for Cool Massive Stars

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Recently, new solar model atmospheres have been developed to replace classical 1D LTE hydrostatic models and used to for example derive the solar chemical composition. We aim to test various models against key observational constraints. In…

Solar and Stellar Astrophysics · Physics 2015-06-15 Tiago M. D. Pereira , Martin Asplund , Remo Collet , Irina Thaler , Regner Trampedach , Jorrit Leenaarts

Models of thermal emission of neutron stars, presumably formed in their atmospheres, are needed to infer the surface temperatures, magnetic fields, chemical composition, and neutron star masses and radii from the observational data. This…

Astrophysics · Physics 2007-05-23 V. E. Zavlin , G. G. Pavlov

Mass loss plays a crucial role in the lives of massive stars, especially as the star leaves the main sequence and evolves to the red supergiant (RSG) phase. However, the physical processes that trigger mass-loss events in RSGs are not well…

Solar and Stellar Astrophysics · Physics 2024-03-05 G. González-Torà , M. Wittkowski , B. Davies , B. Plez

We study the spectroscopic and photometric properties of carbon stars. In the first paper of this series we focus on objects that can be described by hydrostatic models neglecting dynamical phenomena like pulsation and mass loss. As a…

Solar and Stellar Astrophysics · Physics 2015-05-13 B. Aringer , L. Girardi , W. Nowotny , P. Marigo , M. T. Lederer

We present an analytic 1-D radiative-convective model of the thermal structure of planetary atmospheres. Our model assumes that thermal radiative transfer is gray and can be represented by the two-stream approximation. Model atmospheres are…

Earth and Planetary Astrophysics · Physics 2012-09-11 Tyler D. Robinson , David C. Catling

One of the major tasks in interpretation of data from large-scale stellar surveys is to determine the fundamental atmospheric parameters such as effective temperature, surface gravity, and metallicity. In most on-going and upcoming…

Solar and Stellar Astrophysics · Physics 2015-06-16 L. Mashonkina

We investigate the properties of the cool circumgalactic medium (CGM) of massive galaxies and their cosmic evolution. By using the year 1 dataset of luminous red galaxies (LRGs) and QSOs from the Dark Energy Spectroscopic Instrument survey,…

Red supergiants (RSGs) are evolved massive stars that represent extremes, in both their physical sizes and their cool temperatures, of the massive star population. Effective temperature ($T_{\rm eff}$) is the most critical physical property…

Solar and Stellar Astrophysics · Physics 2019-04-15 Brooke Dicenzo Emily M. Levesque

Models of stellar structure and evolution are an indispensable tool in astrophysics, yet they are known to incorrectly reproduce the outer convective layers of stars. In the first paper of this series, we presented a novel procedure to…

We report the results of 1-D hydrodynamical modelling of the evolution of gas in galaxy clusters. We have incorporated many of the effects missing from earlier 1-D treatments: improved modelling of the dark matter and galaxy distributions,…

Astrophysics · Physics 2015-06-24 P. A. Knight , T. J. Ponman

We present our NextGen Model Atmosphere grid for low mass stars for effective temperatures larger than $3000\K$. These LTE models are calculated with the same basic model assumptions and input physics as the VLMS part of the NextGen grid so…

Astrophysics · Physics 2008-11-26 Peter H. Hauschildt , France Allard , E. Baron

We describe a self-consistent spectrum analysis technique employing non-LTE line formation, which allows precise atmospheric parameters of massive stars to be derived: 1sigma-uncertainties as low as ~1% in effective temperature and…

Solar and Stellar Astrophysics · Physics 2015-03-17 Maria-Fernanda Nieva , Norbert Przybilla

The abundance of galactic systems at high redshifts can impose a strong constraint on the cold+hot dark matter (CDM+HDM) models. The hot component reduces the excessive small-scale power in the COBE-normalized CDM model but also delays the…

Astrophysics · Physics 2009-10-22 Chung-Pei Ma , Edmund Bertschinger

We present a theoretical study of the effects and signatures of realistic velocity field and atmospheric inhomogeneities associated with convective motions at the surface of cool late-type stars on the emergent profiles of iron spectral…

Solar and Stellar Astrophysics · Physics 2014-03-26 Zazralt Magic , Remo Collet , Martin Asplund

We have identified seven red supergiants (RSGs) in the Large Magellanic Cloud (LMC) and four RSGs in the Small Magellanic Cloud (SMC), all of which have spectral types that are considerably later than the average type observed in their…

Astrophysics · Physics 2009-06-23 Emily M. Levesque , Philip Massey , K. A. G. Olsen , Bertrand Plez

Analyzing the spectra from Wolf-Rayet stars requires adequate non-LTE modeling of their expanding atmosphere. The numerical schemes for solving the radiative transfer in the co-moving frame of reference have been developed by Mihalas and…

Solar and Stellar Astrophysics · Physics 2014-11-20 W. -R. Hamann , G. Graefener , L. M. Oskinova , A. Feldmeier

As one of the most important elements in astronomy, iron abundance determinations need to be as accurate as possible. We investigate the accuracy of spectroscopic iron abundance analyses using archetypal metal-poor stars. We perform…

Solar and Stellar Astrophysics · Physics 2016-09-15 A. M. Amarsi , K. Lind , M. Asplund , P. S. Barklem , R. Collet

We develop 3-D models of the structured winds of massive hot stars with the Wind3D radiative transfer (RT) code. We investigate the physical properties of large-scale structures observed in the wind of the B-type supergiant HD 64760 with…

Solar and Stellar Astrophysics · Physics 2016-08-14 A. Lobel , J. A. Toalá , R. Blomme

We use the MARCS stellar atmosphere to derive the physical properties of 36 red supergiants (RSGs) in the LMC, and 39 RSGs in the SMC using moderate-resolution optical spectrophotometry (4000-9000A) and broad-band colors (V-R, V-K). The…

Theoretical predictions of Red Giant Branch stars' effective temperatures, colors, luminosities and surface chemical abundances are a necessary tool for the astrophysical interpretation of the visible--near infrared integrated light from…

Astrophysics · Physics 2009-11-07 M. Salaris , S. Cassisi , A. Weiss
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