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Related papers: Interplanetary Lyman $\alpha$ line profiles: varia…

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Using data from the MIRIS Pa{\alpha} Galactic Plane Survey (MIPAPS), we present a Pa{\alpha} 1.87 um line image of the entire Galactic plane within the latitude range of -3{\deg} < b < +3{\deg}, revealing numerous Pa{\alpha} features. Based…

Astrophysics of Galaxies · Physics 2025-06-26 Il-Joong Kim , Jeonghyun Pyo , Kwang-Il Seon , Woong-Seob Jeong , Takao Nakagawa , Toshio Matsumoto

The Polarimetric and Helioseismic Imager (SO/PHI) onboard Solar Orbiter is a spectropolarimeter scanning the Fe I line at 617.3 nm, providing data of the solar photosphere. The same line is sampled by the Helioseismic and Magnetic Imager…

Empirical relations between major UV and extreme UV spectral lines are one of the inputs for models of chromospheric and coronal spectral radiances and irradiances. They are also needed for the interpretation of some of the observations of…

We study intermittency as a departure from self-similarity of the solar wind magnetic turbulence and investigate the evolution with the heliocentric distance and latitude. We use data from the Ulysses spacecraft measured during two solar…

Space Physics · Physics 2016-08-24 Anna Wawrzaszek , Marius Echim , Wiesław M. Macek , Roberto Bruno

Spectral lines allow us to probe the thermodynamics of the solar atmosphere, but the shape of a single spectral line may be similar for different thermodynamic solutions. Multiline analyses are therefore crucial, but computationally…

Solar and Stellar Astrophysics · Physics 2021-05-19 Brandon Panos , Lucia Kleint , Sviatoslav Voloshynovskiy

The review presents analysis and physical interpretation of available statistical data about solar wind plasma and interplanetary magnetic field (IMF) properties as measured in-situ at 1 A.U. by numerous space experiments during time period…

Space Physics · Physics 2013-01-15 A. V. Dmitriev , A. V. Suvorova , I. S. Veselovsky

The galactic cosmic rays (GCR) suffer from solar modulation when they propagate through the heliosphere. The transfer of the local interstellar spectrum (LIS) to the top-of-atmosphere spectra (TOA) is influenced by solar wind convection,…

High Energy Astrophysical Phenomena · Physics 2024-12-10 Cheng-Rui Zhu

We use state-of-the-art radiation-MHD simulations and 3D non-LTE radiative transfer computations to investigate \Halpha\ line formation in the solar chromosphere and apply the results of this investigation to develop the potential of…

Solar and Stellar Astrophysics · Physics 2015-06-04 Jorrit Leenaarts , Mats Carlsson , Luc Rouppe van der Voort

The global rotational profile of the solar atmosphere and its variation at different layers, although crucial for a comprehensive understanding of the dynamics of the solar magnetic field, has been a subject to contradictory results…

We have used STIS aboard HST to search for Lyman-alpha (Lya) absorption in the outer regions of nine nearby (cz<6000 km/s) galaxies using background QSOs and AGN as probes. The foreground galaxies are intercepted between 26 and 199 h-1 kpc…

Astrophysics · Physics 2017-08-23 David V. Bowen , Max Pettini , J. Chris Blades

Alfven waves and ion-cyclotron absorption of high-frequency waves are frequently brought into models devoted to coronal heating and fast solar-wind acceleration. Signatures of ion-cyclotron resonance have already been observed in situ in…

Astrophysics · Physics 2009-11-13 L. Dolla , J. Solomon

We report new HST COS and STIS spectroscopy of a star-forming region (~100 solar masses/year) in the center of the X-ray cluster RXJ1532.9+3021 (z=0.362), to follow-up the CLASH team discovery of luminous UV filaments and knots in the…

Astrophysics of Galaxies · Physics 2017-02-08 Megan Donahue , Thomas Connor , G. Mark Voit , Marc Postman

Lyman-$\alpha$ emission, which owing to its resonant nature strongly couples the emergent line profile to gas kinematics, is a key observable for probing outflows from star-forming galaxies in the early universe. Inferences of outflow…

Astrophysics of Galaxies · Physics 2025-07-31 James Nianias , Jeremy Lim , Yik Lok Wong , Gordon Wong

We present VLT/SINFONI near-infrared (NIR) integral field spectroscopy of six $z \sim 0.2$ Lyman break galaxy "analogs" (LBAs), from which we detect HI, HeI, and [FeII] recombination lines, and multiple H$_2$ ro-vibrational lines in…

Astrophysics of Galaxies · Physics 2019-12-30 John F. Wu , Andrew J. Baker , Timothy M. Heckman , Erin K. S. Hicks , Dieter Lutz , Linda J. Tacconi

CONTEXT: Spectral-line asymmetries and wavelength shifts are signatures of hydrodynamics in solar and stellar atmospheres. Theory may precisely predict idealized lines, but observed spectra are limited by blends, too few suitable lines,…

Astrophysics · Physics 2009-11-13 Dainis Dravins

The Aim of our study is to understand the variety of observed Lyman-alpha (Lya) line profiles and strengths in Lyman Break Galaxies (LBGs) and Lya emitters (LAEs), the physical parameters governing them, and hence deriving constraints on…

Astrophysics · Physics 2009-11-13 Anne Verhamme , Daniel Schaerer , Hakim Atek , Christian Tapken

We study the physical properties of the Lyman-alpha forest by applying the inversion method described by Pichon et al. (2001) to the high resolution and high S/N ratio spectrum of the z_em=2.40 quasar HE 1122-1628 obtained during Science…

Astrophysics · Physics 2009-11-06 E. Rollinde , P. Petitjean , C. Pichon

The Lyman-alpha (Ly{\alpha};1216 {\AA}) line is the brightest emission line in the quiescent solar spectrum and radiates a significant fraction of the available nonthermal energy during flares. Despite its importance, there is a lack of…

Solar and Stellar Astrophysics · Physics 2025-04-25 Luke Majury , Ryan Milligan , Elizabeth Butler , Harry Greatorex , Maria Kazachenko

The Lyman $\alpha$ (Ly$\alpha$) line from high-redshift galaxies is a powerful probe of the Epoch of Reionization (EoR). Neutral hydrogen in the intergalactic medium (IGM) can significantly attenuate the emergent Ly$\alpha$ line, even in…

Astrophysics of Galaxies · Physics 2026-02-17 Samuel Gagnon-Hartman , Andrei Mesinger , Ivan Nikolić , Eleonora Parlanti , Giacomo Venturi

We have analyzed a time series of spectra in the hydrogen Lyman lines and the Lyman continuum obtained by the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer on the SOlar Heliospheric Observatory (SOHO). The time…

Astrophysics · Physics 2008-04-24 R. Kariyappa , B. A. Varghese , W. Curdt
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