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相关论文: Correlating Intrinsic Stellar Parameters with Mg I…

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We present a novel framework to self-consistently model the effects of radiation fields, dust physics and molecular chemistry (H$_2$) in the interstellar medium (ISM) of galaxies. The model combines a state-of-the-art radiation…

Aims: We investigate a new method to for obtaining the plasma parameters of solar prominences observed in the Mgii h&k spectral lines by comparing line profiles from the IRIS satellite to a bank of profiles computed with a one-dimensional…

太阳与恒星天体物理 · 物理学 2021-09-01 Aaron W. Peat , Nicolas Labrosse , Brigitte Schmieder , Krzysztof Barczynski

We present a self-consistent three-dimensional Monte-Carlo radiative transfer model of the stellar and dust emission in the Milky-Way, and have computed synthetic observations of the 3.6 to 100 microns emission in the Galactic mid-plane. In…

We outline theoretical predictions for extended emission from MgII, tracing cool ~10^4 K gas in the circumgalactic medium (CGM) of star-forming galaxies in the high-resolution TNG50 cosmological magnetohydrodynamical simulation. We…

星系天体物理 · 物理学 2021-08-11 Dylan Nelson , Chris Byrohl , Celine Peroux , Kate H. R. Rubin , Joseph N. Burchett

We use 3D radiation magnetohydrodynamic models to investigate how the thermodynamic quantities in the simulation are encoded in observable quantities, thus exploring the diagnostic potential of the 133.5 nm lines. We find that the line core…

太阳与恒星天体物理 · 物理学 2015-09-30 Bhavna Rathore , Mats Carlsson , Jorrit Leenaarts , Bart De Pontieu

The opacity due to photodissociation of 24MgH is investigated in the atmospheres of cool stars. The lowest two electronic transitions A 2Pi -- X 2Sigma+ and B' 2Sigma+ -- X 2 Sigma+ are considered where the cross sections for the latter…

天体物理学 · 物理学 2009-11-07 P. F. Weck , A. Schweitzer , P. C. Stancil , P. H. Hauschildt , K. Kirby

The Interface Region Imaging Spectrograph(IRIS) with its high spatial and temporal resolution brings exceptional plasma diagnostics of solar chromospheric and coronal activity during magnetic reconnection. The aim of this work is to study…

太阳与恒星天体物理 · 物理学 2021-01-20 Reetika Joshi , Brigitte Schmieder , Akiko Tei , Guillaume Aulanier , Juraj Lörinčík , Ramesh Chandra , Petr Heinzel

The photon-scattering winds of M-giants absorb parts of the chromospheric emission lines and produce self-reversed spectral features in high resolution {\it HST}/GHRS spectra. These spectra provide an opportunity to assess fundamental…

太阳与恒星天体物理 · 物理学 2018-12-12 Gioia Rau , Krister E. Nielsen , Kenneth G. Carpenter , Vladimir Airapetian

High resolution optical (HIRES/Keck) and UV (STIS/HST) spectra, covering a large range of chemical transitions, are analyzed for three single-cloud weak MgII absorption systems along the line of sight toward the quasar PG 1634+706. Weak…

天体物理学 · 物理学 2008-11-26 J. C. Charlton , J. Ding , S. G. Zonak , C. W. Churchill , N. A. Bond , J. R. Rigby

The increasing number of spectra gathered by spectroscopic sky surveys and transiting exoplanet follow-up has pushed the community to develop automated tools for atmospheric stellar parameters determination. Here we present a novel approach…

太阳与恒星天体物理 · 物理学 2017-06-28 Luca Malavolta , Christophe Lovis , Francesco Pepe , Christopher Sneden , Stephane Udry

The detailed chemical composition of stars is important in many astrophysical fields, among which the characterisation of exoplanetary systems. Previous studies seem to indicate an anomalous chemical pattern of the youngest stellar…

Lyman-$\alpha$ (Ly$\alpha$) is the most prominent ultraviolet emission line in low-mass stars, playing a crucial role in exoplanet atmospheric photochemistry, heating, and escape. However, interstellar medium (ISM) absorption typically…

We have used GIM2D to quantify the morphological properties of 40 intermediate redshift MgII absorption-selected galaxies (0.03<Wr(2796)<2.9 Ang), imaged with WFPC-2/HST, and compared them to the halo gas properties measured form HIRES/Keck…

宇宙学与河外天体物理 · 物理学 2015-05-28 G. G. Kacprzak , C. W. Churchill , Jessica L. Evans , M. T. Murphy , Charles C. Steidel

The hardness of the ionizing continuum from the first sources of UV radiation plays a crucial role in the reionization of the intergalactic medium (IGM). While usual stellar populations have soft spectra, mini-quasars or metal-free stars…

天体物理学 · 物理学 2009-10-31 S. Peng Oh , Zoltan Haiman , Martin J. Rees

We present an initial survey of Mg II absorption characteristics in the halos of a carefully constructed, volume-limited subsample of galaxies embedded in the spectroscopic part of the Sloan Digital Sky Survey. We observed quasars near…

宇宙学与河外天体物理 · 物理学 2015-05-14 Elizabeth J. Barton , Jeff Cooke

We investigate the prospects for detecting and constraining density and temperature inhomogeneities in the circumgalactic medium (CGM) using absorption measurements of metal ions. Distributions in the gas thermal properties could arise from…

星系天体物理 · 物理学 2024-06-07 Yakov Faerman , Daniel R. Piacitelli , Matthew McQuinn , Jessica K. Werk

The main purpose of this study is to use the IUE spectra in the analysis of magnetic activity of main sequence F-K stars. Combining IUE observations of MgII and optical spectroscopy of Ca II, the registry of ctivity of stars can be extended…

天体物理学 · 物理学 2009-11-13 Andrea P. Buccino , Pablo J. D. Mauas

The fundamental process of star formation in galaxies involves the interplay between the fueling of star formation via molecular gas and the feedback from recently formed massive stars. This process, by which galaxies evolve, is also…

Massive stars can alter physical conditions and properties of their ambient interstellar dust grains via radiative heating and shocks. The HII regions in the Large Magellanic Cloud (LMC) offer ideal sites to study the stellar energy…

About 70-80% of stars in our solar and galactic neighborhood are M dwarfs. They span a range of low masses and temperatures relative to solar-type stars, facilitating molecule formation throughout their atmospheres. Standard stellar…

太阳与恒星天体物理 · 物理学 2023-02-22 Aishwarya R. Iyer , Michael R. Line , Philip S. Muirhead , Jonathan J. Fortney , Ehsan Gharib-Nezhad