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相关论文: Ly$\alpha$ Spectra from Multiphase Outflows, and t…

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We suggest that low optical depth in the Lyman continuum (LyC) may relate the Ly-alpha emission, C II and Si II absorption, and C II* and Si II* emission seen in high-redshift galaxies. We base this analysis on Hubble Space Telescope COS…

星系天体物理 · 物理学 2015-06-22 A. E. Jaskot , M. S. Oey

We developed a Monte Carlo code that describes the resonant Lyman alpha line transfer in an optically thick, dusty, and static medium. The code was tested against the analytic formula derived by Neufeld (1990). We explain the line transfer…

天体物理学 · 物理学 2016-08-30 Sang-Hyeon Ahn , Hee-Won Lee , Hyung-Mok Lee

The peaked-spectrum (PS) sources exhibit turnover characteristics in their broad radio spectra. However, the mechanism underlying this phenomenon remains elusive. The two most common hypotheses are synchrotron self-absorption (SSA) and…

星系天体物理 · 物理学 2025-05-26 Guang-Chen Sun , Yichao Li , Furen Deng , Yanping Cong , Fangxia An , Jiajun Zhang , Yougang Wang , Xin Zhang , Xuelei Chen

Using the CoDa II simulation, we study the Ly$\alpha$ transmissivity of the intergalactic medium (IGM) during reionization. At $z>6$, a typical galaxy without an active galactic nucleus fails to form a proximity zone around itself due to…

The physical origin of diffuse Ly$\alpha$ halos (LAHs) around star-forming galaxies is still a matter of debate. We present the dependence of LAH luminosity ($L({\rm Ly}\alpha)_H$) on the stellar mass ($M_\star$), $SFR$, color excess…

The hydrogen Lyman-alpha plays a dominant role in the radiative energy transport in the lower transition region, and is important for the stud- ies of transition-region structure as well as solar wind origin. We investigate the Ly-alpha…

太阳与恒星天体物理 · 物理学 2014-11-20 Hui Tian , Luca Teriaca , Werner Curdt , Jean-Claude Vial

We investigate Lyman-alpha (Ly$\alpha$) transmission spikes at $5.2 < z < 6.8$ using synthetic quasar spectra from the ``Cosmic Reionization On Computers" simulations. We focus on understanding the relationship between these spikes and the…

宇宙学与河外天体物理 · 物理学 2025-07-01 Hanjue Zhu , Nickolay Gnedin , Camille Avestruz

The intensity and the linear scattering polarization profiles of the hydrogen Ly-alpha line encode valuable information on the thermodynamic and magnetic structure of the upper layers of the solar chromosphere. The Chromospheric Lyman-Alpha…

太阳与恒星天体物理 · 物理学 2023-05-03 Ernest Alsina Ballester , Luca Belluzzi , Javier Trujillo Bueno

Lyman-alpha (Lya) photons that escape the interstellar medium of star-forming galaxies may be resonantly scattered by neutral hydrogen atoms in the circumgalactic and intergalactic media, thereby increasing the angular extent of the…

宇宙学与河外天体物理 · 物理学 2015-05-20 Zheng Zheng , Renyue Cen , David Weinberg , Hy Trac , Jordi Miralda-Escude

We present statistical properties of diffuse Lyman-alpha halos (LAHs) around high-$z$ star-forming galaxies with large Subaru samples of Lyman-alpha emitters (LAEs) at $z=2.2$. We make subsamples defined by the physical quantities of LAEs'…

As a result of resonant scatterings off hydrogen atoms, Lyman-alpha (Lya) emission from star-forming galaxies provides a probe of the (hardly isotropic) neutral gas environment around them. We study the effect of the environmental…

宇宙学与河外天体物理 · 物理学 2015-06-16 Zheng Zheng , Joshua Wallace

We analyze the spectra of $10$ Green Pea galaxies, previously studied by Henry et al. (2015), using a semi-analytical line transfer (SALT) model to interpret emission and absorption features observed in UV galactic spectra. We focus our…

星系天体物理 · 物理学 2021-01-20 Cody Carr , Claudia Scarlata , Alaina Henry , Nino Panagia

The 2s_{1/2} state of hydrogen is metastable and overpopulated in HII regions. In addition, the 2p states may be pumped by ambient Lyman-alpha radiation. Fine structure transitions between these states may be observable in HII regions at…

天体物理学 · 物理学 2009-11-11 Brian Dennison , B. E. Turner , Anthony H. Minter

We present results of Monte Carlo calculations for the Lya line transfer in an expanding dusty supershell, where Lya source is a well-localized star cluster in a starburst galaxy.The escape of Lya photons from such system is achieved by a…

天体物理学 · 物理学 2009-11-10 Sang-Hyeon Ahn

It has been suggested that radiative transfer effects may explain the unusually high equivalent widths (EWs) of the Lya line, observed occasionally from starburst galaxies, especially at high redshifts. If the dust is locked up inside…

宇宙学与河外天体物理 · 物理学 2015-06-12 Peter Laursen , Florent Duval , Göran Östlin

Extended Lyman-alpha emission is now commonly detected around high redshift galaxies through stacking and even on individual basis. Despite recent observational advances, the physical origin of these Lyman-alpha halos (LAHs), as well as…

The hydrogen Lyman-alpha (Lya) emission line, the brightest spectral feature of a photoionized gas, is considered an indirect tracer of the escape of Lyman continuum (LyC) photons, particularly when the intergalactic medium is too opaque…

We search for galaxy counterparts to damped Lyman-alpha absorbers (DLAs) at z>2 towards nine quasars, which have 14 DLAs and 8 sub-DLAs in their spectra. We use integral field spectroscopy to search for Ly-alpha emission line objects at the…

天体物理学 · 物理学 2007-06-13 L. Christensen , L. Wisotzki , M. M. Roth , S. F. Sanchez , A. Kelz , K. Jahnke

We present observations with the Cosmic Origins Spectrograph onboard the Hubble Space Telescope of eight compact star-forming galaxies at redshifts z=0.02811-0.06540, with low oxygen abundances 12+log(O/H)=7.43-7.82 and extremely high…

星系天体物理 · 物理学 2019-11-27 Y. I. Izotov , D. Schaerer , G. Worseck , A. Verhamme , N. G. Guseva , T. X. Thuan , I. Orlitova , K. J. Fricke

Galactic outflows have a multiphase nature making them challenging to model analytically. Many previous studies have tried to produce models that come closer to reality. In this work, we continue these efforts and describe the interaction…

星系天体物理 · 物理学 2024-06-17 C. Nikolis , M. Gronke