On the post-asymptotic giant branch model for the far-ultraviolet emission in elliptical galaxies

1989 ◽  
Vol 339 ◽  
pp. 889 ◽  
Author(s):  
G. Bertelli ◽  
C. Chiosi ◽  
F. Bertola
Keyword(s):  
Elliptical Galaxies ◽  
Asymptotic Giant Branch ◽  
Ultraviolet Emission ◽  
Branch Model ◽  
Far Ultraviolet

Far-Ultraviolet Emission from Elliptical Galaxies at [CLC][ITAL]z[/ITAL][/CLC] = 0.33

2003 ◽  
Vol 584 (2) ◽  
pp. L69-L72 ◽  
Author(s):  
Thomas M. Brown ◽  
Henry C. Ferguson ◽  
Ed Smith ◽  
Charles W. Bowers ◽  
Randy A. Kimble ◽  
...  
Keyword(s):  
Elliptical Galaxies ◽  
Ultraviolet Emission ◽  
Far Ultraviolet

Far-Ultraviolet Emission from Elliptical Galaxies at [CLC][ITAL]z[/ITAL][/CLC] = 0.55

2000 ◽  
Vol 529 (2) ◽  
pp. L89-L93 ◽  
Author(s):  
Thomas M. Brown ◽  
Charles W. Bowers ◽  
Randy A. Kimble ◽  
Henry C. Ferguson
Keyword(s):  
Elliptical Galaxies ◽  
Ultraviolet Emission ◽  
Far Ultraviolet

High-resolution far ultraviolet emission spectra of electron-excited molecular deuterium

1999 ◽  
Vol 32 (15) ◽  
pp. 3813-3838 ◽  
Author(s):  
H Abgrall ◽  
E Roueff ◽  
Xianming Liu ◽  
D E Shemansky ◽  
G K James
Keyword(s):  
High Resolution ◽  
Emission Spectra ◽  
Ultraviolet Emission ◽  
Far Ultraviolet

scholarly journals The Periods of RR Lyrae

1993 ◽  
Vol 139 ◽  
pp. 409-409
Author(s):  
Arthur N. Cox
Keyword(s):  
Asymptotic Giant Branch ◽  
Natural Mode ◽  
Composition Gradient ◽  
Near Surface ◽  
Rr Lyrae ◽  
Extensive Evaluation ◽  
Branch Model ◽  
Convective Core ◽  
Pure Helium ◽  
Nonradial Mode

AbstractRR Lyrae (0.566 day period) exhibits the Blasko effect that suggests another natural mode with almost the same period as the accepted fundamental radial mode. This mode might be nonradial, but no one has done an extensive evaluation of this idea. An investigation requires a model that includes the deep composition structure where g-modes of low angular (observable) degree have weight and amplitude. An RR Lyrae model including the outer half of the mass and more than 99% of the radius, based on an asymptotic giant branch model from Hollowell (private communication), see below, was used for this study. It includes composition gradient ramps between the primordial surface hydrogen and helium and the almost pure helium shell and the one between this helium shell and the convective core that is burning helium.Nonradial mode periods almost resonant with the radial fundamental mode period seem to occur for all low ℓ values. In addition to significant pulsation amplitudes in the composition gradient regions where the Brunt Väisälä frequency is large, these low degree and low radial order modes have near-surface amplitudes very similar to the low order radial modes. These modes are evanescent in the convective core. Classical K and γ effects give enough driving in the very low mass surface layers, so that important deep radiative damping for these modes does not completely stabilize nonradial g-mode pulsations. The g4, ℓ=1 mode gives a. double-mode RR Lyrae with Blasko effect.A nonradial mode may not always be visible, depending on how rotation presents the nonspherical pulsations to the observer. Thus the Blasko effect might come and go, as observed for maybe 20% of all RR Lyrae variables. For many, the Blasko effect may not be observable, even when a nonradial mode is there.

A search for far-ultraviolet emission from Sirius B

1978 ◽  
Vol 225 ◽  
pp. L67 ◽  
Author(s):  
W. H. Brune ◽  
P. D. Feldman ◽  
G. H. Mount
Keyword(s):  
Ultraviolet Emission ◽  
Far Ultraviolet

High-Resolution Electron-Impact Study of the Far-Ultraviolet Emission Spectrum of Molecular Hydrogen

1995 ◽  
Vol 101 ◽  
pp. 375 ◽  
Author(s):  
Xianming Liu ◽  
Syed M. Ahmed ◽  
Rosalie A. Multari ◽  
Geoffrey K. James ◽  
Joseph M. Ajello
Keyword(s):  
High Resolution ◽  
Emission Spectrum ◽  
Electron Impact ◽  
Molecular Hydrogen ◽  
Impact Study ◽  
Ultraviolet Emission ◽  
Resolution Electron ◽  
Far Ultraviolet

scholarly journals The power spectrum of the Lyman-α Forest at z < 0.5

2019 ◽  
Vol 486 (1) ◽  
pp. 769-782 ◽  
Author(s):  
Vikram Khaire ◽  
Michael Walther ◽  
Joseph F Hennawi ◽  
Jose Oñorbe ◽  
Zarija Lukić ◽  
...  
Keyword(s):  
Power Spectrum ◽  
Intergalactic Medium ◽  
Thermal State ◽  
Hubble Space Telescope ◽  
Companion Paper ◽  
Metal Line ◽  
Ultraviolet Emission ◽  
Line Spread Function ◽  
Quasar Spectra ◽  
Far Ultraviolet

ABSTRACT We present new measurements of the flux power-spectrum P(k) of the z &lt; 0.5 H  i Lyman-α Forest spanning scales $k \sim 0.001\!-\!0.1\, \mathrm{s \, km}^{-1}$. These results were derived from 65 far-ultraviolet quasar spectra (resolution $R \sim 18\, 000$) observed with the Cosmic Origin Spectrograph (COS) on board the Hubble Space Telescope. The analysis required careful masking of all contaminating, coincident absorption from H  i and metal–line transitions of the Galactic interstellar medium and intervening absorbers as well as proper treatment of the complex COS line-spread function. From the P(k) measurements, we estimate the H  i photoionization rate ($\Gamma _{\rm H\,{\small I}}$) in the z &lt; 0.5 intergalactic medium. Our results confirm most of the previous $\Gamma _{\rm H\,{\small I}}$ estimates. We conclude that previous concerns of a photon underproduction crisis are now resolved by demonstrating that the measured $\Gamma _{\rm H\,{\small I}}$ can be accounted for by ultraviolet emission from quasars alone. In a companion paper, we will present constraints on the thermal state of the z &lt; 0.5 intergalactic medium from the P(k) measurements presented here.

scholarly journals Far-ultraviolet Emission from Supernova Remnant Shocks

2000 ◽  
Vol 195 ◽  
pp. 425-426
Author(s):  
R. Sankrit ◽  
W. P. Blair ◽  
Fuse Snr Team
Keyword(s):  
Supernova Remnants ◽  
Supernova Remnant ◽  
Ultraviolet Emission ◽  
Far Ultraviolet ◽  
Rich Spectrum

Supernova remnant shocks produce a rich spectrum of lines in the ultraviolet. Among these are important diagnostic resonance lines of O VI, C III, and N III which lie in the bandpass observable with the recently launched Far Ultraviolet Spectroscopic Explorer. We present an overview of a PI program to observe several supernova remnants using this new telescope.

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