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相关论文: An empirical calibration of the mixing-length para…

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Red giants in the updated APOGEE-Kepler catalogue, with estimates of mass, chemical composition, surface gravity and effective temperature, have recently challenged stellar models computed under the standard assumption of solar calibrated…

太阳与恒星天体物理 · 物理学 2018-05-16 M. Salaris , S. Cassisi , R. P. Schiavon , A. Pietrinferni

This paper is a further step in the investigation of the morphology of the color-magnitude diagram of Galactic globular clusters, and the fine-tuning of theoretical models, made possible by the recent observational efforts to build…

天体物理学 · 物理学 2007-05-23 Rossella Palmieri , Giampaolo Piotto , Ivo Saviane , Leo Girardi , Vittorio Castellani

Based on detailed 2D numerical radiation hydrodynamics (RHD) calculations of time-dependent compressible convection, we have studied the dynamics and thermal structure of the convective surface layers of solar-type stars. The RHD models…

天体物理学 · 物理学 2007-05-23 H. -G. Ludwig , B. Freytag , M. Steffen

Stellar models typically use the mixing length approximation as a way to implement convection in a simplified manner. While conventionally the value of the mixing length parameter, $\alpha$, used is the solar calibrated value, many studies…

太阳与恒星天体物理 · 物理学 2018-05-16 Lucas S. Viani , Sarbani Basu , Joel J. M. Ong , Ana Bonaca , William J. Chaplin

We present empirical metallicity-dependent calibrations of effective temperature against colours for dwarfs of luminosity classes IV and V and for giants of luminosity classes II and III, based on a collection from the literature of about…

太阳与恒星天体物理 · 物理学 2015-10-28 Yang Huang , Xiao-Wei Liu , Hai-Bo Yuan , Mao-sheng Xiang , Bing-Qiu Chen , Hua-Wei Zhang

Stellar models generally use simple parametrizations to treat convection. The most widely used parametrization is the so-called "Mixing Length Theory" where the convective eddy sizes are described using a single number, \alpha, the…

Assuming that in the atmospheres of low-mass, metal-poor red giant stars, 1-D models based on LTE accurately predict the abundance of iron from Fe II, we derive a globular cluster metallicity scale based on the equivalent widths of Fe II…

天体物理学 · 物理学 2009-07-28 Robert P. Kraft , Inese I. Ivans

We present evolutionary models for solar-like stars with an improved treatment of convection that results in a more accurate estimate of the radius and effective temperature. This is achieved by improving the calibration of the…

太阳与恒星天体物理 · 物理学 2021-04-28 Federico Spada , Pierre Demarque , Friedrich Kupka

We present a technique that applies spectral synthesis to medium resolution spectroscopy (MRS, R ~ 6000) in the red (6300 A < lambda < 9100 A) to measure [Fe/H] and [alpha/Fe] of individual red giant stars over a wide metallicity range. We…

天体物理学 · 物理学 2008-08-09 Evan N. Kirby , Puragra Guhathakurta , Christopher Sneden

We have obtained spectra with resolution 2.5 Angstroms in the region 7500-9500 Angstroms for 116 red giants in 5 Galactic globular clusters and 6 old open clusters (5 with published metallicities, and one previously unmeasured). The…

天体物理学 · 物理学 2009-11-10 A. A. Cole , T. A. Smecker-Hane , E. Tolstoy , T. L. Bosler , J. S. Gallagher

We present new determinations of bolometric corrections and effective temperature scales as a function of infrared and optical colors, using a large database of photometric observations of about 6500 Population II giants in Galactic…

天体物理学 · 物理学 2010-02-18 P. Montegriffo , F. R. Ferraro , L. Origlia , F. Fusi Pecci

Two-dimensional hydrodynamical simulations were made to calibrate the mixing length parameter for modeling red giant's convective envelope. As was briefly reported in Asida & Tuchman (97), a comparison of simulations starting with models…

天体物理学 · 物理学 2009-10-31 S. M. Asida

In the updated APOGEE-Kepler catalog, we have asteroseismic and spectroscopic data for over 3000 first ascent red giants. Given the size and accuracy of this sample, these data offer an unprecedented test of the accuracy of stellar models…

In order to accurately determine stellar properties, knowledge of the effective temperature of stars is vital. We implement Gaia and 2MASS photometry in the InfraRed Flux Method and apply it to over 360,000 stars across different…

Hydrodynamic simulations of Lyman alpha clouds based on ab inito cosmological models have produced results that are in broad agreement with observations. However, further analyses have revealed that, with progressively higher numerical…

天体物理学 · 物理学 2009-10-31 Renyue Cen , Greg L. Bryan

Metallicity is one of four free parameters typically considered when fitting isochrones to the cluster sequence. Unfortunately, this parameter is often ignored or assumed to be solar in most papers. Hence an unknown bias is introduced in…

太阳与恒星天体物理 · 物理学 2010-08-23 E. Paunzen , U. Heiter , M. Netopil , C. Soubiran

We present broad-band infrared photometry for 52 late-type supergiants in the young Magellanic Clouds clusters NGC 330, NGC 1818, NGC 2004 and NGC 2100. Standard models are seen to differ in the temperature they predict for the red…

天体物理学 · 物理学 2009-10-31 Stefan C. Keller

We use the Stetson, HST, and Gaia DR3 data sets for 22 Galactic globular clusters to select their members and fit their CMDs with isochrones from DSED and BaSTI for $[\alpha/$Fe$]=+0.4$ and an adopted helium mass fraction $Y$. As a result,…

星系天体物理 · 物理学 2026-05-28 G. A. Gontcharov , O. S. Ryutina , C. J. Bonatto , S. S. Savchenko , S. V. Troitsky

We present high quality near infrared Color Magnitude Diagrams of 10 Galactic Globular Clusters (GCs) spanning a wide metallicity range (-2.15<[Fe/H]<-0.2). This homogeneous data-base has been used to perform a detailed analysis of the Red…

天体物理学 · 物理学 2009-10-31 Francesco R. Ferraro , Paolo Montegriffo , Livia Origlia , Flavio Fusi Pecci

Various effective temperature scales have been proposed over the years. Despite much work and the high internal precision usually achieved, systematic differences of order 100 K (or more) among various scales are still present. We present…

太阳与恒星天体物理 · 物理学 2010-04-07 L. Casagrande , I. Ramirez , J. Melendez , M. Bessell , M. Asplund
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