scholarly journals Tracking the Lyman alpha emission line in the CircumGalactic Medium in MUSE data

2016 ◽  
Vol 78-79 ◽  
pp. 233-245
Author(s):  
R. Bacher ◽  
P. Maho ◽  
F. Chatelain ◽  
O. Michel
Keyword(s):  
Emission Line ◽  
Lyman Alpha ◽  
Alpha Emission ◽  
Circumgalactic Medium

scholarly journals Lyman Edges in Quasar Spectra

1989 ◽  
Vol 134 ◽  
pp. 555-556
Author(s):  
A. L. Kinney ◽  
R.R.J. Antonucci ◽  
H. C. Ford
Keyword(s):  
High Resolution ◽  
Emission Line ◽  
High Redshift ◽  
Edge Region ◽  
Disk Model ◽  
High Resolution Data ◽  
Lyman Alpha ◽  
Alpha Emission ◽  
Quasar Spectra ◽  
Resolution Data

This is a study of the Lyman edge region in the spectra of eleven high redshift quasars. We present large aperture, low resolution data designed to detect broadened Lyman edge absorption predicted by thermal models of the Big Blue Bump continuum component. We also present high resolution data on the edge regions and the Lyman alpha emission line for nine of the objects. We show some partial absorption edges and discuss whether or not they can be interpreted as support for the accretion disk model.

The Solar Lyman-Alpha Emission Line.

1961 ◽  
Vol 133 ◽  
pp. 596 ◽  
Author(s):  
Donald C. Morton ◽  
Kenneth G. Widing
Keyword(s):  
Emission Line ◽  
Lyman Alpha ◽  
Alpha Emission

Ionized gas kinematics and luminosity profiles of Low-z Lyman Alpha Blobs

2019 ◽  
Vol 15 (S359) ◽  
pp. 413-414
Author(s):  
María P. Agüero ◽  
Rubén Díaz ◽  
Mischa Schirmer
Keyword(s):  
Emission Line ◽  
Galactic Nuclei ◽  
Host Galaxies ◽  
Ionized Gas ◽  
Lyman Alpha ◽  
Gas Kinematics ◽  
The Universe ◽  
Very High ◽  
The Continuum

AbstractThis work is focused on the characterization of the Seyfert-2 galaxies hosting very large, ultra-luminous narrow-line regions (NLRs) at redshifts z = 0.2−0.34. With a space density of 4.4 Gcp−3 at z ∼ 0.3, these “Low Redshift Lyman-α Blob” (LAB) host galaxies are amongst the rarest objects in the universe, and represent an exceptional and short-lived phenomenon in the life cycle of active galactic nuclei (AGNs). We present the study of GMOS spectra for 13 LAB galaxies covering the rest frame spectral range 3700–6700 Å. Predominantly, the [OIII]λ5007 emission line radial distribution is as widespread as that of the continuum one. The emission line profiles exhibit FWHM between 300–700 Km s−1. In 7 of 13 cases a broad kinematical component is detected with FWHM within the range 600–1100 Km s−1. The exceptionally high [OIII]λ5007 luminosity is responsible for very high equivalent width reaching 1500 Å at the nucleus.

scholarly journals Solar Irradiance Variability Due to Solar Flares Observed in Lyman-Alpha Emission

Solar Physics ◽  
2021 ◽  
Vol 296 (3) ◽  
Author(s):  
Ryan O. Milligan
Keyword(s):  
Solar Flares ◽  
Solar Spectrum ◽  
Neutral Hydrogen ◽  
Solar Limb ◽  
High Background ◽  
Superposed Epoch Analysis ◽  
Lyman Alpha ◽  
Alpha Emission ◽  
Epoch Analysis ◽  
Very High

AbstractAs the Lyman-alpha (Ly$\upalpha $ α ) line of neutral hydrogen is the brightest emission line in the solar spectrum, detecting increases in irradiance due to solar flares at this wavelength can be challenging due to the very high background. Previous studies that have focused on the largest flares have shown that even these extreme cases generate enhancements in Ly$\upalpha $ α of only a few percent above the background. In this study, a superposed-epoch analysis was performed on ≈8500 flares greater than B1 class to determine the contribution that they make to changes in the solar EUV irradiance. Using the peak of the 1 – 8 Å X-ray emission as a fiducial time, the corresponding time series of 3123 B- and 4972 C-class flares observed in Ly$\upalpha $ α emission by the EUV Sensor on the Geostationary Operational Environmental Satellite 15 (GOES-15) were averaged to reduce background fluctuations and improve the flare signal. The summation of these weaker events showed that they produced a 0.1 – 0.3% enhancement to the solar Ly$\upalpha $ α irradiance on average. For comparison, the same technique was applied to 453 M- and 31 X-class flares, which resulted in a 1 – 4% increase in Ly$\upalpha $ α emission. Flares were also averaged with respect to their heliographic angle to investigate any potential center-to-limb variation. For each GOES class, the relative enhancement in Ly$\upalpha $ α at the flare peak was found to diminish for flares that occurred closer to the solar limb due to the opacity of the line and/or foreshortening of the footpoints. One modest event included in the study, a C6.6 flare, exhibited an unusually high increase in Ly$\upalpha $ α of 7% that may have been attributed to a failed filament eruption. Increases of this magnitude have hitherto only been associated with a small number of X-class flares.

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