The far-ultraviolet continuum of quasars and the universe at Z greater than 4

1985 ◽  
Vol 289 ◽  
pp. 451 ◽  
Author(s):  
H. Netzer
Keyword(s):  
Ultraviolet Continuum ◽  
Far Ultraviolet ◽  
The Universe

scholarly journals Background Light from Population III Stars

1987 ◽  
Vol 117 ◽  
pp. 414-414
Author(s):  
Jonathan C. McDowell
Keyword(s):  
Dark Matter ◽  
Background Radiation ◽  
Large Fraction ◽  
Rest Mass ◽  
Critical Density ◽  
Density Parameter ◽  
Extragalactic Background Light ◽  
Background Light ◽  
Far Ultraviolet ◽  
The Universe

It has been proposed (e.g. Carr, Bond and Arnett 1984) that the first generation of stars may have been Very Massive Objects (VMOs, of mass above 200 M⊙) which existed at large redshifts and left a large fraction of the mass of the universe in black hole remnants which now provide the dynamical ‘dark matter’. The radiation from these stars would be present today as extragalactic background light. For stars with density parameter Ω* which convert a fraction ϵ of their rest-mass to radiation at a redshift of z, the energy density of background radiation in units of the critical density is ΩR = εΩ* / (1+z). The VMOs would be far-ultraviolet sources with effective temperatures of 105 K. If the radiation is not absorbed, the constraints provided by measurements of background radiation imply (for H =50 km/s/Mpc) that the stars cannot close the universe unless they formed at a redshift of 40 or more. To provide the dark matter (of one-tenth closure density) the optical limits imply that they must have existed at redshifts above 25.

The origin of the far-ultraviolet continuum in solar and stellar flares

1992 ◽  
Vol 385 ◽  
pp. 731 ◽  
Author(s):  
K. J. H. Phillips ◽  
G. E. Bromage ◽  
J. G. Doyle
Keyword(s):  
Ultraviolet Continuum ◽  
Stellar Flares ◽  
Far Ultraviolet

Voyager Observations of Diffuse Far-Ultraviolet Continuum and Line Emission in Eridanus

1993 ◽  
Vol 419 ◽  
pp. 739 ◽  
Author(s):  
Jayant Murthy ◽  
M. Im ◽  
R. C. Henry ◽  
J. B. Holberg
Keyword(s):  
Line Emission ◽  
Ultraviolet Continuum ◽  
Far Ultraviolet

scholarly journals FAR-ULTRAVIOLET CONTINUUM EMISSION: APPLYING THIS DIAGNOSTIC TO THE CHROMOSPHERES OF SOLAR-MASS STARS

2011 ◽  
Vol 745 (1) ◽  
pp. 25 ◽  
Author(s):  
Jeffrey L. Linsky ◽  
Rachel Bushinsky ◽  
Tom Ayres ◽  
Juan Fontenla ◽  
Kevin France
Keyword(s):  
Continuum Emission ◽  
Ultraviolet Continuum ◽  
Solar Mass ◽  
Far Ultraviolet

scholarly journals OBSERVATION OF THE FAR-ULTRAVIOLET CONTINUUM BACKGROUND WITH SPEAR/FIMS

2011 ◽  
Vol 196 (2) ◽  
pp. 15 ◽  
Author(s):  
Kwang-Il Seon ◽  
Jerry Edelstein ◽  
Eric Korpela ◽  
Adolf Witt ◽  
Kyoung-Wook Min ◽  
...  
Keyword(s):  
Ultraviolet Continuum ◽  
Far Ultraviolet

Far‐Ultraviolet Continuum of G‐Type Stars: A Signature of the Temperature Minimum Region

1998 ◽  
Vol 508 (1) ◽  
pp. 370-379 ◽  
Author(s):  
M. Franchini ◽  
C. Morossi ◽  
M. L. Malagnini
Keyword(s):  
Temperature Minimum ◽  
Ultraviolet Continuum ◽  
Far Ultraviolet

scholarly journals THE FAR-ULTRAVIOLET “CONTINUUM” IN PROTOPLANETARY DISK SYSTEMS. II. CARBON MONOXIDE FOURTH POSITIVE EMISSION AND ABSORPTION

2011 ◽  
Vol 734 (1) ◽  
pp. 31 ◽  
Author(s):  
Kevin France ◽  
Eric Schindhelm ◽  
Eric B. Burgh ◽  
Gregory J. Herczeg ◽  
Graham M. Harper ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Protoplanetary Disk ◽  
Ultraviolet Continuum ◽  
Far Ultraviolet

scholarly journals 44. Astronomical Observations From Outside The Terrestrial Atmosphere

1976 ◽  
Vol 16 (3) ◽  
pp. 195-220
Author(s):  
A. D. Code
Keyword(s):  
Electromagnetic Spectrum ◽  
X Ray ◽  
Earth’S Atmosphere ◽  
The Earth ◽  
Accessible Region ◽  
Earth's Atmosphere ◽  
Far Ultraviolet ◽  
General Secretary ◽  
The Universe

Commission 44 is by title technique oriented. The following statement of the role of the commission was prepared for use by the General Secretary in responding to requests by non-astronomers with respect to the activities of IAU commissions.‘The Earth’s atmosphere is opaque to radiation throughout most of the electromagnetic spectrum. The light reaching the surface of the Earth from celestial objects is confined primarily to the visual region of the spectrum and a larger window in the radio region. Much of the infrared and all the far ultraviolet, X-ray and γ-ray radiation are absorbed in the upper atmosphere. Thus astronomers must carry their telescopes and auxiliary instrumentation above the Earth’s atmosphere to unlock the clues on the structure of the universe revealed by the light at these wavelengths. Furthermore the light in the accessible region of the spectrum that does reach the surface of the Earth is distorted and scattered in such a manner that the spatial resolution and details of the radiating source is seriously degraded.

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