On-Orbit Performance of the [ITAL]Far Ultraviolet Spectroscopic Explorer[/ITAL] Satellite

Sahnow, David J.; Moos, H. W.; Ake, Thomas B.; Andersen, J.; Andersson, B. G.; André, M.; Artis, David; Berman, A. F.; Blair, William P.; Brownsberger, K. R.; Calvani, Humberto; Chayer, P.; Conard, Steven J.; Feldman, P. D.; Friedman, S. D.; Fullerton, A. W.; Gaines, Geoffrey A.; Gawne, W. C.; Green, J. C.; Gummin, Mark A.; Jennings, T.; Joyce, J. B.; Kaiser, M. E.; Kruk, J. W.; Lindler, Don J.; Massa, Derck; Murphy, E. M.; Oegerle, W. R.; Ohl, Raymond G.; Roberts, Bryce; Romelfanger, M. L.; Roth, Katherine C.; Sankrit, Ravi; Sembach, Kenneth R.; Shelton, R. L.; Siegmund, Oswald H. W.; Silva, C. J.; Sonneborn, G.; Vaclavik, S. R.; Weaver, Harold A.; Wilkinson, Erik

doi:10.1086/312794

Cited by 423 publications

(174 citation statements)

References 15 publications

Supporting

Mentioning

172

Contrasting

Order By: Relevance

“…For a description of the satellite and its capabilities see Moos et al (2000) and Sahnow et al (2000). and BD +28 • 4211) located at distances of 104-179 pc outside of the LB.…”

Section: Fuse Measurements Of D/h Along the Lines Of Sight To Nearby mentioning

confidence: 99%

Atomic Deuterium/Hydrogen in the Galaxy

Linsky

2003

Solar System History From Isotopic Signatures of Volatile Elements

View full text Add to dashboard Cite

Abstract. An accurate value of the deuterium/hydrogen (D/H) ratio in the local interstellar medium (LISM) and a better understanding of the D/H variations with position in the Galactic disk can provide essential information on the primordial D/H ratio in the Galaxy at the time of the protosolar nebula, and the amount of astration and mixing in the Galaxy over time. Recent measurements have been obtained with UV spectrographs on FUSE, HST, and IMAPS using hot white dwarfs, OB stars, and late-type stars as background light sources against which to measure absorption by D and H in the interstellar medium along the lines of sight. Recent analyses of FUSE observations of seven white dwarfs and subdwarfs provide a weighted mean value of D/H = (1.52 ± 0.08) × 10 −5 (15.2 ± 0.8 ppm), consistent with the value of (1.50 ± 0.10) × 10 −5 (15.0 ± 1.0 ppm) obtained from analysis of lines of sight toward nearby late-type stars. Both numbers refer to the ISM within about 100 pc of the Sun, which samples warm clouds located within the Local Bubble. Outside of the Local Bubble at distances of 200 to 500 pc, analyses of far-UV spectra obtained with IMAPS indicate a much wider range of D/H ratios between 0.8 to 2.2 ppm, providing information on inhomogeneous astration in the Galactic disk. Why are Accurate Measurements of the D/H Ratio Important?Measurements of D/H, the number ratio of deuterium in all forms to hydrogen in all forms, are important for at least two reasons. First, an accurate measurement of the primordial ratio, (D/H) prim , counts the number of baryons in the universe to determine the ratio Ω B of the baryon density to the closure density, and tests our assumptions concerning nucleosynthesis during the first 100-1,000 seconds of the universe (e.g., Burles et al., 2001). Deuterium is our best probe of primordial nucleosynthesis because theory predicts that D was formed only in the very early universe, D is the easiest isotope to be destroyed by nuclear reactions in stars (astration), and Ω B is a very sensitive single-valued function of (D/H) prim . The best approximation to (D/H) prim would be an accurate measurement of D/H in gas where there has been little chemical fractionation or star formation, as indicated by very low metal abundances, but such measurements remain difficult.Second, measurements of D/H in different locations in our Galaxy will provide an accurate test of the assumptions underlying Galactic chemical evolution models. A major problem in astrophysics is understanding how galaxies evolve and, in particular, how the chemical element abundances evolve. In broad overview, we know that stars form out of gas clouds and over time they destroy D, create metals, and return some of this deuterium-poor and metal-rich material to the ISM by winds and supernova explosions. The detailed rates for these processes depend on the Space Science Reviews 95/96: 1-12, 2003.

show abstract

“…For a description of the satellite and its capabilities see Moos et al (2000) and Sahnow et al (2000). and BD +28 • 4211) located at distances of 104-179 pc outside of the LB.…”

Section: Fuse Measurements Of D/h Along the Lines Of Sight To Nearby mentioning

confidence: 99%

Atomic Deuterium/Hydrogen in the Galaxy

Linsky

2003

Solar System History From Isotopic Signatures of Volatile Elements

View full text Add to dashboard Cite

show abstract

“…The dotted column density profiles in Figures 7 and 8 do not include thermal broadening and were constructed by summing the contributions from all the cells along the line of sight, assuming that each cell's column density profile is a Dirac δ function at v. The solid column density profiles do include thermal broadening, which we approximated by convolving each cell's column density profile with a boxcar of full width 2b, where b = (0.129 km s −1 ) √ (T /K)/A is the thermal velocityspread parameter, T is the gas temperature in the cell, and A is the relative atomic mass of the ion in question (Spitzer 1978, Equation (3-21)). Note that the profiles in Figures 7 and 8 are much broader than the FUSE spectral resolution (∼20 km s −1 ; Sahnow et al 2000;Wood et al 2002).…”

Section: Column Density Profilesmentioning

confidence: 96%

Simulations of High-Velocity Clouds. Ii. Ablation From High-Velocity Clouds as a Source of Low-Velocity High Ions

Henley

Kwak

Shelton

2012

ApJ

View full text Add to dashboard Cite

In order to determine if the material ablated from high-velocity clouds (HVCs) is a significant source of low-velocity high ions (C iv, N v, and O vi) such as those found in the Galactic halo, we simulate the hydrodynamics of the gas and the time-dependent ionization evolution of its carbon, nitrogen, and oxygen ions. Our suite of simulations examines the ablation of warm material from clouds of various sizes, densities, and velocities as they pass through the hot Galactic halo. The ablated material mixes with the environmental gas, producing an intermediate-temperature mixture that is rich in high ions and that slows to the speed of the surrounding gas. We find that the slow mixed material is a significant source of the low-velocity O vi that is observed in the halo, as it can account for at least ∼1/3 of the observed O vi column density. Hence, any complete model of the high ions in the halo should include the contribution to the O vi from ablated HVC material. However, such material is unlikely to be a major source of the observed C iv, presumably because the observed C iv is affected by photoionization, which our models do not include. We discuss a composite model that includes contributions from HVCs, supernova remnants, a cooling Galactic fountain, and photoionization by an external radiation field. By design, this model matches the observed O vi column density. This model can also account for most or all of the observed C iv, but only half of the observed N v.

show abstract

“…The low resolution G140L grating (as well as the G130M grating in new off nominal, low resolution configurations) are sensitive down to at least the Lyman limit (900Å) with effective area comparable to or significantly larger than those of the Far Ultraviolet Spectroscopic Explorer (FUSE) over the same wavelength range, although at lower resolution , Sahnow et al (2000)). …”

Section: Fuv Sensitivitymentioning

confidence: 99%

The Cosmic Origins Spectrograph: on-orbit instrument performance

Osterman¹,

Green²,

Froning³

et al. 2011

UV Astronomy 2011

Self Cite

View full text Add to dashboard Cite

The Cosmic Origins Spectrograph (COS) was installed in the Hubble Space Telescope in May, 2009 as part of Servicing Mission 4 to provide high sensitivity, medium and low resolution spectroscopy at farand near-ultraviolet wavelengths (FUV, NUV). COS is the most sensitive FUV/NUV spectrograph flown to date, spanning the wavelength range from 900Å to 3200Å with peak effective area approaching 3000 cm 2 . This paper describes instrument design, the results of the Servicing Mission Orbital Verification (SMOV), and the ongoing performance monitoring program.

show abstract

On-Orbit Performance of the [ITAL]Far Ultraviolet Spectroscopic Explorer[/ITAL] Satellite

Cited by 423 publications

References 15 publications

Atomic Deuterium/Hydrogen in the Galaxy

Atomic Deuterium/Hydrogen in the Galaxy

Simulations of High-Velocity Clouds. Ii. Ablation From High-Velocity Clouds as a Source of Low-Velocity High Ions

The Cosmic Origins Spectrograph: on-orbit instrument performance

Contact Info

Product

Resources

About