Lyα EMISSION FROM GREEN PEAS: THE ROLE OF CIRCUMGALACTIC GAS DENSITY, COVERING, AND KINEMATICS

@article{Henry2015LyEF,
  title={Ly$\alpha$ EMISSION FROM GREEN PEAS: THE ROLE OF CIRCUMGALACTIC GAS DENSITY, COVERING, AND KINEMATICS},
  author={Alaina L. Henry and Claudia Scarlata and Crystal L. Martin and Dawn K. Erb},
  journal={The Astrophysical Journal},
  year={2015},
  volume={809}
}
We report Hubble Space Telescope/Cosmic Origins Spectrograph observations of the Lyα emission and interstellar absorption lines in a sample of 10 star-forming galaxies at z ∼ 0.2. Selected on the basis of high equivalent width optical emission lines, the sample, dubbed “Green Peas,” make some of the best analogs for young galaxies in an early universe. We detect Lyα emission in all ten galaxies, and 9/10 show double-peaked line profiles suggestive of low H i column density. We measure Lyα/H… 
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References

SHOWING 1-10 OF 89 REFERENCES
Lyα ESCAPE FROM z ∼ 0.03 STAR-FORMING GALAXIES: THE DOMINANT ROLE OF OUTFLOWS
The usefulness of H i Lyα photons for characterizing star formation in the distant universe is limited by our understanding of the astrophysical processes that regulate their escape from galaxies.
Lyα EMITTING GALAXIES AS EARLY STAGES IN GALAXY FORMATION
We present optical spectroscopy of two samples of Galaxy Evolution Explorer grism selected Lyα emitters (LAEs): one at z = 0.195–0.44 and the other at z = 0.65–1.25. We have also observed a
EXTENDED Lyα EMISSION AROUND STAR-FORMING GALAXIES
Lyα 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
Diffuse Lyα Emitting Halos: A Generic Property of High-redshift Star-forming Galaxies
Using a sample of 92 UV continuum-selected, spectroscopically identified galaxies with 〈z〉 = 2.65, all of which have been imaged in the Lyα line with extremely deep narrow-band imaging, we examine
What is the physical origin of strong Lya emission? II. Gas Kinematics and Distribution of Lya Emitters
We present a statistical study of velocities of Lyα, interstellar (IS) absorption, and nebular lines and gas covering fraction for Lyα emitters (LAEs) at z ≃ 2. We make a sample of 22 LAEs with a
Rest-Frame Ultraviolet Spectra of z ∼ 3 Lyman Break Galaxies*
We present the results of a systematic study of the rest-frame UV spectroscopic properties of Lyman break galaxies (LBGs). The database of almost 1000 LBG spectra proves useful for constructing high
The LyAlpha Line Profiles of Ultraluminous Infrared Galaxies: Fast Winds and Lyman Continuum Leakage
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
The Lyman Alpha Reference Sample. Ii. Hubble Space Telescope Imaging Results, Integrated Properties, And Trends
We report new results regarding the Lyα output of galaxies, derived from the Lyman Alpha Reference Sample, and focused on Hubble Space Telescope imaging. For 14 galaxies we present intensity images
KECK SPECTROSCOPY OF FAINT 3>z>7 LYMAN BREAK GALAXIES: A HIGH FRACTION OF LINE EMITTERS AT REDSHIFT SIX
As Lyα photons are scattered by neutral hydrogen, a change with redshift in the Lyα equivalent width (EW) distribution of distant galaxies offers a promising probe of the degree of ionization in the
The Lyman Alpha Reference Sample: Extended Lyman Alpha Halos Produced at Low Dust Content
We report on new imaging observations of the Lyman alpha emission line (Lyα), performed with the Hubble Space Telescope, that comprise the backbone of the Lyman alpha Reference Sample. We present
...
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