O VI in the local interstellar medium

M. A. Barstow, D. D. Boyce, B. Y. Welsh, R. Lallement, J. K. Barstow, A. E. Forbes, S. Preval

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

We report the results of a search for Ovi absorption in the spectra of 80 hot DA white dwarfs observed by the FUSE satellite. We have carried out a detailed analysis of the radial velocities of interstellar and (where present) stellar absorption lines for the entire sample of stars. In approximately 35% of cases (where photospheric material is detected), the velocity differences between the interstellar and photospheric components were beneath the resolution of the FUSE spectrographs. Therefore, in 65% of these stars the interstellar and photospheric contributions could be separated and the nature of the Ovi component unambiguously determined. Furthermore, in other examples, where the spectra were of a high signal-to-noise, no photospheric material was found and any Ovi detected was assumed to be interstellar. Building on the earlier work of Oegerle et al. and Savage and Lehner, we have increased the number of detections of interstellar Ovi and, for the first time, compared their locations with both the soft X-ray background emission and new detailed maps of the distribution of neutral gas within the local interstellar medium. We find no strong evidence to support a spatial correlation between Ovi and SXRB emission. In all but a few cases, the interstellar Ovi was located at or beyond the boundaries of the local cavity. Hence, any T ∼ 300,000 K gas responsible for the Ovi absorption may reside at the interface between the cavity and surrounding medium or in that medium itself. Consequently, it appears that there is much less Ovi-bearing gas than previously stated within the inner rarefied regions of the local interstellar cavity.

LanguageEnglish
Pages1762-1786
Number of pages25
JournalAstrophysical Journal
Volume723
Issue number2
DOIs
Publication statusPublished - 10 Nov 2010

Fingerprint

Far UV Spectroscopic Explorer
cavity
cavities
gas
stars
gas bearings
neutral gases
radial velocity
spectrographs
gases
x rays
material
distribution
detection
analysis

Keywords

  • clouds
  • white dwarf stars
  • interstellar medium structure
  • ultraviolet interstellar medium
  • ultraviolet stars
  • white dwarfs

Cite this

Barstow, M. A., Boyce, D. D., Welsh, B. Y., Lallement, R., Barstow, J. K., Forbes, A. E., & Preval, S. (2010). O VI in the local interstellar medium. Astrophysical Journal, 723(2), 1762-1786. https://doi.org/10.1088/0004-637X/723/2/1762
Barstow, M. A. ; Boyce, D. D. ; Welsh, B. Y. ; Lallement, R. ; Barstow, J. K. ; Forbes, A. E. ; Preval, S. / O VI in the local interstellar medium. In: Astrophysical Journal. 2010 ; Vol. 723, No. 2. pp. 1762-1786.
@article{b251ab45c4164a8585f8e45966ac643d,
title = "O VI in the local interstellar medium",
abstract = "We report the results of a search for Ovi absorption in the spectra of 80 hot DA white dwarfs observed by the FUSE satellite. We have carried out a detailed analysis of the radial velocities of interstellar and (where present) stellar absorption lines for the entire sample of stars. In approximately 35{\%} of cases (where photospheric material is detected), the velocity differences between the interstellar and photospheric components were beneath the resolution of the FUSE spectrographs. Therefore, in 65{\%} of these stars the interstellar and photospheric contributions could be separated and the nature of the Ovi component unambiguously determined. Furthermore, in other examples, where the spectra were of a high signal-to-noise, no photospheric material was found and any Ovi detected was assumed to be interstellar. Building on the earlier work of Oegerle et al. and Savage and Lehner, we have increased the number of detections of interstellar Ovi and, for the first time, compared their locations with both the soft X-ray background emission and new detailed maps of the distribution of neutral gas within the local interstellar medium. We find no strong evidence to support a spatial correlation between Ovi and SXRB emission. In all but a few cases, the interstellar Ovi was located at or beyond the boundaries of the local cavity. Hence, any T ∼ 300,000 K gas responsible for the Ovi absorption may reside at the interface between the cavity and surrounding medium or in that medium itself. Consequently, it appears that there is much less Ovi-bearing gas than previously stated within the inner rarefied regions of the local interstellar cavity.",
keywords = "clouds, white dwarf stars, interstellar medium structure, ultraviolet interstellar medium, ultraviolet stars, white dwarfs",
author = "Barstow, {M. A.} and Boyce, {D. D.} and Welsh, {B. Y.} and R. Lallement and Barstow, {J. K.} and Forbes, {A. E.} and S. Preval",
year = "2010",
month = "11",
day = "10",
doi = "10.1088/0004-637X/723/2/1762",
language = "English",
volume = "723",
pages = "1762--1786",
journal = "Astrophysical Journal",
issn = "0004-637X",
number = "2",

}

Barstow, MA, Boyce, DD, Welsh, BY, Lallement, R, Barstow, JK, Forbes, AE & Preval, S 2010, 'O VI in the local interstellar medium' Astrophysical Journal, vol. 723, no. 2, pp. 1762-1786. https://doi.org/10.1088/0004-637X/723/2/1762

O VI in the local interstellar medium. / Barstow, M. A.; Boyce, D. D.; Welsh, B. Y.; Lallement, R.; Barstow, J. K.; Forbes, A. E.; Preval, S.

In: Astrophysical Journal, Vol. 723, No. 2, 10.11.2010, p. 1762-1786.

Research output: Contribution to journalArticle

TY - JOUR

T1 - O VI in the local interstellar medium

AU - Barstow, M. A.

AU - Boyce, D. D.

AU - Welsh, B. Y.

AU - Lallement, R.

AU - Barstow, J. K.

AU - Forbes, A. E.

AU - Preval, S.

PY - 2010/11/10

Y1 - 2010/11/10

N2 - We report the results of a search for Ovi absorption in the spectra of 80 hot DA white dwarfs observed by the FUSE satellite. We have carried out a detailed analysis of the radial velocities of interstellar and (where present) stellar absorption lines for the entire sample of stars. In approximately 35% of cases (where photospheric material is detected), the velocity differences between the interstellar and photospheric components were beneath the resolution of the FUSE spectrographs. Therefore, in 65% of these stars the interstellar and photospheric contributions could be separated and the nature of the Ovi component unambiguously determined. Furthermore, in other examples, where the spectra were of a high signal-to-noise, no photospheric material was found and any Ovi detected was assumed to be interstellar. Building on the earlier work of Oegerle et al. and Savage and Lehner, we have increased the number of detections of interstellar Ovi and, for the first time, compared their locations with both the soft X-ray background emission and new detailed maps of the distribution of neutral gas within the local interstellar medium. We find no strong evidence to support a spatial correlation between Ovi and SXRB emission. In all but a few cases, the interstellar Ovi was located at or beyond the boundaries of the local cavity. Hence, any T ∼ 300,000 K gas responsible for the Ovi absorption may reside at the interface between the cavity and surrounding medium or in that medium itself. Consequently, it appears that there is much less Ovi-bearing gas than previously stated within the inner rarefied regions of the local interstellar cavity.

AB - We report the results of a search for Ovi absorption in the spectra of 80 hot DA white dwarfs observed by the FUSE satellite. We have carried out a detailed analysis of the radial velocities of interstellar and (where present) stellar absorption lines for the entire sample of stars. In approximately 35% of cases (where photospheric material is detected), the velocity differences between the interstellar and photospheric components were beneath the resolution of the FUSE spectrographs. Therefore, in 65% of these stars the interstellar and photospheric contributions could be separated and the nature of the Ovi component unambiguously determined. Furthermore, in other examples, where the spectra were of a high signal-to-noise, no photospheric material was found and any Ovi detected was assumed to be interstellar. Building on the earlier work of Oegerle et al. and Savage and Lehner, we have increased the number of detections of interstellar Ovi and, for the first time, compared their locations with both the soft X-ray background emission and new detailed maps of the distribution of neutral gas within the local interstellar medium. We find no strong evidence to support a spatial correlation between Ovi and SXRB emission. In all but a few cases, the interstellar Ovi was located at or beyond the boundaries of the local cavity. Hence, any T ∼ 300,000 K gas responsible for the Ovi absorption may reside at the interface between the cavity and surrounding medium or in that medium itself. Consequently, it appears that there is much less Ovi-bearing gas than previously stated within the inner rarefied regions of the local interstellar cavity.

KW - clouds

KW - white dwarf stars

KW - interstellar medium structure

KW - ultraviolet interstellar medium

KW - ultraviolet stars

KW - white dwarfs

UR - http://www.scopus.com/inward/record.url?scp=78650182349&partnerID=8YFLogxK

UR - http://arxiv.org/abs/1009.5255

U2 - 10.1088/0004-637X/723/2/1762

DO - 10.1088/0004-637X/723/2/1762

M3 - Article

VL - 723

SP - 1762

EP - 1786

JO - Astrophysical Journal

T2 - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

ER -

Barstow MA, Boyce DD, Welsh BY, Lallement R, Barstow JK, Forbes AE et al. O VI in the local interstellar medium. Astrophysical Journal. 2010 Nov 10;723(2):1762-1786. https://doi.org/10.1088/0004-637X/723/2/1762