English
Related papers

Related papers: Hydrogen Lyman-alpha and Lyman-beta spectral radia…

200 papers

We describe a moderate-resolution (20-25 km/s) FUSE study of the low-redshift intergalactic medium. We report on studies of 7 extragalactic sightlines and 12 Ly-beta absorbers that correspond to Ly-alpha lines detected by HST/GHRS and STIS.…

The visibility of LyA emitting galaxies during the Epoch of Reionization is controlled by both diffuse HI patches in large-scale bubble morphology and small-scale absorbers. To investigate the impact on LyA photons, we apply a novel…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-07 Koki Kakiichi , Mark Dijkstra , Benedetta Ciardi , Luca Graziani

The Lya line transfer in an extremely thick medium of neutral hydrogen is investigated by adopting an accelerating scheme in our Monte Carlo code to skip a large number of core or resonant scatterings. This scheme reduces computing time…

Astrophysics · Physics 2009-11-07 Sang-Hyeon Ahn , Hee-Won Lee , Hyung Mok Lee

Spectra of the QSO pair Q0307-195A,B have been obtained in the Ly-alpha Forest (3660 - 3930 A) and C IV (4720 - 4850 A) regions with a FWHM resolution between 0.7 and 0.5 A. 46 lines have been detected in the spectrum of object A while 36…

Astrophysics · Physics 2010-04-06 V. D'Odorico , S. Cristiani , S. D'Odorico , A. Fontana , E. Giallongo , P. Shaver

The H I Lyman-alpha (Ly$\alpha$) emission, with a wavelength of 1216 \r{A}, is the brightest solar ultraviolet (UV) line. However, comprehensive observations of the Ly$\alpha$ emission line across the full solar disk remain limited. As part…

Solar and Stellar Astrophysics · Physics 2025-05-23 Yiliang Li , Ping Zhang , Zhengyuan Tian , Li Feng , Guanglu Shi , Jianchao Xue , Ying Li , Jun Tian , Kaifan Ji , Beili Ying , Lei Lu , Shuting Li , Jiahui Shan , Hui Li , Weiqun Gan

The Lyman alpha (LyA) line of neutral hydrogen plays a central role in observations of star-forming galaxies. However, resonant scattering makes it difficult to directly interpret LyA signatures. Monte Carlo radiative transfer (MCRT)…

Astrophysics of Galaxies · Physics 2025-12-11 Kevin Lorinc , Aaron Smith , Olof Nebrin , Joshua Kasiri

The Lyman-alpha emission line is the strongest feature in the spectrum of most high redshift galaxies, and is typically observed as being highly asymmetric due to galactic outflows. Quantifying this asymmetry is challenging. Here, we…

Astrophysics of Galaxies · Physics 2018-08-08 Henry J. T. Childs , Elizabeth R. Stanway

We examine Lyman continuum (LyC) leakage through H II regions regulated by turbulence and radiative feedback in a giant molecular cloud in the context of fully-coupled radiation hydrodynamics (RHD). The physical relations of the LyC escape…

Astrophysics of Galaxies · Physics 2021-11-17 Koki Kakiichi , Max Gronke

We present zELDA(redshift Estimator for Line profiles of Distant Lyman-Alpha emitters), an open source code to fit Lyman-Alpha (Lya) line profiles. The main motivation is to provide the community with an easy to use and fast tool to analyze…

Astrophysics of Galaxies · Physics 2021-12-22 Siddhartha Gurung-Lopez , Max Gronke , Shun Saito , Silvia Bonoli , Alvaro A. Orsi

We present spatially resolved maps of six individually-detected Lyman alpha haloes (LAHs) as well as a first statistical analysis of the Lyman alpha (Lya) spectral signature in the circum-galactic medium of high-redshift star-forming…

We perform Lyman-alpha radiative transfer calculations for reproducing Lyman-alpha properties of star-forming galaxies at high redshifts. We model a galaxy as a halo in which the density distributions of Lyman-alpha sources and H I plus…

Astrophysics of Galaxies · Physics 2020-09-30 Hyunmi Song , Kwang-Il Seon , Ho Seong Hwang

We develop a prescription for characterizing the strengths of metal lines associated with Lyman-alpha forest absorbers (LYFAs) of a given neutral hydrogen column density N_HI and metallicity [Fe/H]. This Line Observability Index (LOX) is…

Astrophysics · Physics 2009-10-30 Uffe Hellsten , Lars Hernquist , Neal Katz , David Weinberg

Based on the Sloan Digital Sky Survey Data Release 16, we have detected the large-scale structure of Ly$\alpha$ emission in the Universe at redshifts $z = 2$--3.5 by cross-correlating quasar positions and Ly$\alpha$ emission imprinted in…

Astrophysics of Galaxies · Physics 2022-09-28 Xiaojing Lin , Zheng Zheng , Zheng Cai

We present the evolution of the 21-cm signal from cosmic dawn and the epoch of reionization (EoR) in an upgraded model including three subtle effects of Ly-a radiation: Ly-a heating, CMB heating (mediated by Ly-a photons), and multiple…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-18 Itamar Reis , Anastasia Fialkov , Rennan Barkana

The recombination of hydrogen and helium at z~1000-7000 gives unavoidable distortions to the Cosmic Microwave Background (CMB) spectrum. We present a detailed calculation of the line intensities arising from the Ly-alpha (2p-1s) and…

Astrophysics · Physics 2009-11-13 Wan Yan Wong , Sara Seager , Douglas Scott

We present new Hubble Space Telescope Cosmic Origins Spectrograph far-ultraviolet (far-UV) spectroscopy and Keck Echellete optical spectroscopy of 11 ultraluminous infrared galaxies (ULIRGs), a rare population of local galaxies experiencing…

Astrophysics of Galaxies · Physics 2015-06-23 Crystal L. Martin , Mark Dijkstra , Alaina Henry , Kurt T. Soto , Charles W. Danforth , Joseph Wong

We present the discovery and subsequent spectroscopy with Gemini-North of the optical afterglow of the Swift gamma-ray burst (GRB) 140515A. The spectrum exhibits a well-detected continuum at wavelengths longer than 8915 Angs with a steep…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-30 R. Chornock , E. Berger , D. B. Fox , W. Fong , T. Laskar , K. C. Roth

We present an analysis of HI Lyman-alpha emission in deep VLT/MUSE observations of two highly magnified and extended galaxies at z=3.5 and 4.03, including a newly discovered, almost complete Einstein ring. While these Lyman-alpha haloes are…

We show how the observed hydrogen Balmer and Lyman emission lines constrain the modeling of quiescent solar prominences. We compare space observations of Lyman lines with ground-based observations of Balmer lines for quiescent solar…

Solar and Stellar Astrophysics · Physics 2012-10-03 G. Stellmacher , E. Wiehr

We report the serendipitous discovery of two objects close in projection with fairly strong emission lines at long wavelength (~9190 A). One (A) seems not to be hosted by any galaxy brighter than V(555)=27.5, or I(814)=26.7 (Vega-based…

Astrophysics · Physics 2009-10-31 Daniel Stern , Andrew J. Bunker , Hyron Spinrad , Arjun Dey