Carbon and Beryllium Extreme Ultraviolet Filters: Far-ultraviolet Performance

1987 ◽  
Vol 34 (11) ◽  
pp. 1491-1500 ◽  
Author(s):  
M.A. Barstow ◽  
B.J. Kent ◽  
M.J. Whiteley ◽  
P.H. Spurrett
Keyword(s):  
Extreme Ultraviolet ◽  
Far Ultraviolet

scholarly journals The Proposed Columbus Mission: High and Low Resolution Spectroscopy in the 100–2000 Å Spectral Region

1984 ◽  
Vol 86 ◽  
pp. 72-75
Author(s):  
Jeffrey L. Linsky
Keyword(s):  
High Resolution ◽  
Spectral Range ◽  
Spectral Region ◽  
Extreme Ultraviolet ◽  
High Spectral Resolution ◽  
Low Resolution ◽  
Interstellar Gas ◽  
Scientists And Engineers ◽  
Ionization Balance ◽  
Far Ultraviolet

For the past year a Joint Working Group of NASA and ESA scientists and engineers has been defining the scientific objectives and instrument parameters for a proposed satellite to obtain far and extreme ultraviolet spectra of stars, interstellar gas, solar system objects, and galaxies. The project, now called Columbus, incorporates the scientific goals of the previously proposed NASA Far Ultraviolet Spectrograph Explorer (FUSE) and ESA Magellan missions.The prime spectral range of Columbus, 900–1200 Å, cannot be observed by IUE or Space Telescope. In this spectral range Copernicus was able to observe bright stars (mv ≤ 6) with high resolution and the Hopkins Ultraviolet Telescope (HUT) will observe faint sources at low resolution, but Columbus will be the first instrument capable of high spectral resolution observations of faint sources (mv ≈ 17). High resolution spectra in the 900–1200 Å region will permit studies of the Lyman lines of atomic H and D, the molecules H2 and HD, resonance lines of C III and O VI, and other species listed in Table 1. Columbus also is being designed to observe the 1200–2000 Å spectral region at high resolution, permitting measurements of many stages of ionization for the same atom (i.e. N I, II, III, V; C II, III, IV; and S II, III, IV, VI). The broad coverage of ionization states is essential for the analysis of interstellar and stellar plasmas where the ionization balance can be quite complex.

scholarly journals ORFEUS observation of the central star of NGC 6543

1997 ◽  
Vol 180 ◽  
pp. 136-136
Author(s):  
J. Zweigle ◽  
M. Grewing ◽  
J. Barnstedt ◽  
M. Gölz ◽  
W. Gringel ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Planetary Nebula ◽  
Extreme Ultraviolet ◽  
Wavelength Region ◽  
Central Star ◽  
University Of California ◽  
Satellite Mission ◽  
Ultraviolet Spectrometer ◽  
Far Ultraviolet ◽  
The University

During the ORFEUS-SPAS (Orbiting Retrievable Far and Extreme Ultraviolet Spectrometer on the Shuttle Pallet Satellite) mission STS-51, flown in September 1993, we observed the central star of the planetary nebula NGC 6543 in the far ultraviolet (90 nm to 115 nm) wavelength region using the University of California, Berkeley spectrometer with a spectral resolution of 0.03 nm.

Spectral Observations of the Extreme Ultraviolet Astronomical Background Radiation

1988 ◽  
Vol 102 ◽  
pp. 63-66
Author(s):  
S. Labov ◽  
S. Bowyer
Keyword(s):  
Interstellar Medium ◽  
Background Radiation ◽  
Extreme Ultraviolet ◽  
Grazing Incidence ◽  
Sounding Rocket ◽  
Interstellar Space ◽  
Spectral Measurements ◽  
Interstellar Gas ◽  
Hot Plasma ◽  
Far Ultraviolet

AbstractObservations in the far ultraviolet and soft x-ray bands suggest that the interstellar medium contains several components of high temperature gas (105to 106K). If large volumes of local interstellar space are filled with this hot plasma, emission lines will be produced in the extreme ultraviolet (EUV). Diffuse EUV radiation, however, has only been detected with photometric instruments; no spectral measurements exist below 520Å. We have designed a unique grazing incidence spectrometer to study the diffuse emission between 80 and 650Å with 10 to 30Å resolution. This instrument was successfully flown on a sounding rocket in April of 1986 and a preliminary analysis reveals several features. In addition to the expected interplanetary He I 584Å emission and the geocoronal He II 304Å emission, other features appear which may originate in the hot ionized interstellar gas. These features are discussed along with the possible implications to the hot phase of the interstellar medium.

scholarly journals The warm-hot circumgalactic medium around EAGLE-simulation galaxies and its detection prospects with X-ray and UV line absorption

2020 ◽  
Vol 498 (1) ◽  
pp. 574-598 ◽  
Author(s):  
Nastasha A Wijers ◽  
Joop Schaye ◽  
Benjamin D Oppenheimer
Keyword(s):  
Column Density ◽  
Extreme Ultraviolet ◽  
Gas Well ◽  
X Ray ◽  
Filling Phase ◽  
Circumgalactic Medium ◽  
Halo Masses ◽  
Collisional Ionization ◽  
Far Ultraviolet ◽  
Halo Gas

ABSTRACT We use the EAGLE (Evolution and Assembly of GaLaxies and their Environments) cosmological simulation to study the distribution of baryons, and far-ultraviolet (O vi), extreme-ultraviolet (Ne viii), and X-ray (O vii, O viii, Ne ix, and Fe xvii) line absorbers, around galaxies and haloes of mass $\,{M}_{\rm {200c}}= 10^{11}$–$10^{14.5} \, \rm {M}_{\odot}$ at redshift 0.1. EAGLE predicts that the circumgalactic medium (CGM) contains more metals than the interstellar medium across halo masses. The ions we study here trace the warm-hot, volume-filling phase of the CGM, but are biased towards temperatures corresponding to the collisional ionization peak for each ion, and towards high metallicities. Gas well within the virial radius is mostly collisionally ionized, but around and beyond this radius, and for O vi, photoionization becomes significant. When presenting observables, we work with column densities, but quantify their relation with equivalent widths by analysing virtual spectra. Virial-temperature collisional ionization equilibrium ion fractions are good predictors of column density trends with halo mass, but underestimate the diversity of ions in haloes. Halo gas dominates the highest column density absorption for X-ray lines, but lower density gas contributes to strong UV absorption lines from O vi and Ne viii. Of the O vii (O viii) absorbers detectable in an Athena X-IFU blind survey, we find that 41 (56) per cent arise from haloes with $\,{M}_{\rm {200c}}= 10^{12.0}{-}10^{13.5} \, \rm {M}_{\odot}$. We predict that the X-IFU will detect O vii (O viii) in 77 (46) per cent of the sightlines passing $\,{M}_{\star }= 10^{10.5}{-}10^{11.0} \, \rm {M}_{\odot}$ galaxies within $100 \, \rm {pkpc}$ (59 (82) per cent for $\,{M}_{\star }\gt 10^{11.0} \, \rm {M}_{\odot}$). Hence, the X-IFU will probe covering fractions comparable to those detected with the Cosmic Origins Spectrograph for O vi.

scholarly journals Observations of Local ISM Emission With the Berkeley EUV/FUV Shuttle Telescope

1984 ◽  
Vol 81 ◽  
pp. 344-347
Author(s):  
Christopher Martin ◽  
Stuart Bowyer
Keyword(s):  
Interstellar Medium ◽  
Spectral Resolution ◽  
Space Shuttle ◽  
Extreme Ultraviolet ◽  
Diffuse Background ◽  
Far Ultraviolet

AbstractThe Berkeley Extreme Ultraviolet/Far Ultraviolet Shuttle Telescope (BEST) will be launched on the Space Shuttle in November, 1984, as part of the NASA UVX project. The Berkeley spectrometer will make observations of the cosmic diffuse background in the 600-1900 Å band, with a spectral resolution of 10 Å. The sensitivity and spectral resolution of the instrument make it ideal for the study of components of the interstellar medium in the 104 - 106K range.

The Lyman Far Ultraviolet Spectroscopic Mission (Invited Paper)

1987 ◽  
Vol 7 (2) ◽  
pp. 173-184 ◽  
Author(s):  
Ian R. Tuohy ◽  
Michael A. Dopita
Keyword(s):  
Molecular Hydrogen ◽  
Extreme Ultraviolet ◽  
European Space Agency ◽  
Light Element ◽  
Grazing Incidence ◽  
Spectral Lines ◽  
Important Species ◽  
Element Abundances ◽  
Space Agency ◽  
Far Ultraviolet

AbstractThe Lyman mission will undertake the first sensitive high resolution spectroscopic observations in the largely unexplored 912-1216Å region. This astrophysically critical wavelength interval is exceedingly rich in diagnostic spectral lines such as the Lyman series of atomic hydrogen and deuterium, the Lyman and Werner bands of molecular hydrogen and deuterium, and the resonance lines of numerous important species including CIII, NI-III and OVI. Lyman will have a major impact in all areas of modern astrophysics, with the most fundamental contribution being the determination of light element abundances in the local interstellar medium and in the intergalactic medium at low redshift. The mapping of hot gas (T ∼ 3 × 105K) and molecular hydrogen and HD in the disk and halo of our galaxy represent additional major objectives for which Lyman is uniquely qualified.The Lyman payload will comprise a grazing incidence telescope and three spectroscopic instruments: the prime spectrograph operating between 912-1250Å with a resolution of λ/ Δλ ∼ 30,000, a far ultraviolet spectrograph (1200-2000Å;λ/ Δλ ∼ 10,000), and an extreme ultraviolet spectrograph (100-900Å; λ /Δλ ∼ 300). Observations will be conducted from a highly efficient 48 hour elliptical orbit which will allow long un-interrupted exposures and real time operations. It is anticipated that Lyman will be launched by Ariane in 1996, and will have an operational lifetime of at least 5 years. Data reception and spacecraft control will be undertaken from ground stations in Spain and in Australia.Lyman is currently being studied at Phase-A level by Australia in close coordination with the European Space Agency. The scientific involvement is the responsibility of the Lyman Science Working Group, composed of members representing the various astronomical institutions in Australia. Funding to support the technical and scientific aspects of the mission is provided via the Australian Space Board and the Department of Industry, Technology and Commerce in recognition of the major opportunity that Lyman presents to the Australian aerospace industry.

scholarly journals The Hopkins Ultraviolet Telescope

1990 ◽  
Vol 123 ◽  
pp. 292-292 ◽  
Author(s):  
A. Davidsen
Keyword(s):  
Time Resolution ◽  
Extreme Ultraviolet ◽  
Effective Area ◽  
Second Order ◽  
Microchannel Plate ◽  
Primary Mirror ◽  
First Order ◽  
Far Ultraviolet

AbstractThe Hopkins Ultraviolet Telescope (HUT) will make pioneering observations in the far ultraviolet (912–1850 Å) and extreme ultraviolet (420–912 Å) bands during its upcoming flight aboard the Astro-1 shuttle mission, currently scheduled for launch on May 9, 1990. HUT employs an iridium-coated 0.9-meter f/2 primary mirror, an osmium-coated grating, and a CsI-coated microchannel plate intensifer to achieve a resolution of about 3 A in first order, with a peak effective area of 15 cm2 at 1100 Å, and time resolution of 2 milliseconds, HUT’s EUV response is obtained in second order, with a peak effective area of 10 cm2 at 600 Å.HUT is expected to obtain several hundred spectra during its upcoming mission, ranging from Comet Austin to the quasar HS 1700+64 at a redshift of 2.7. The design and operation of the instrument are described, and simulated spectra are used to illustrate a sample of the problems that will be addressed during the Astro-1 mission. In order for HUT to be exploited fully, however, it would be desirable to convert it to a free-flying satellite mode

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