Diffuse extreme-ultraviolet emission from the Coma cluster: Evidence for rapidly cooling gases at submegakelvin temperatures

Science

Volumn 274, Issue 5291, 1996, Pages 1335-1338

  Lieu, Richard ^a   Mittaz, Jonathan P D ^b   Bowyer, Stuart ^c   Breen, Jeffrey O ^d   Lockman, Felix J ^e   Murphy, Edward M ^d   Hwang, Chorng Yuan ^c  

^a UNIVERSITY OF ALABAMA IN HUNTSVILLE   (United States)

^b UNIVERSITY COLLEGE LONDON   (United Kingdom)

^c UNIVERSITY OF CALIFORNIA   (United States)

^d UNIVERSITY OF VIRGINIA   (United States)

^e NATIONAL RADIO ASTRONOMY OBSERVATORY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ARTICLE; ASTRONOMY; COOLING; GAS; PRIORITY JOURNAL; TEMPERATURE; ULTRAVIOLET RADIATION; X RAY;

EID: 0029825495     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.274.5291.1335     Document Type: Article

References (27)

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5. This is a dedicated observation with the 43-m telescope of the National Radio Astronomy Observatory at Green Bank, WV. HI spectra were taken every 8 are min over an area of radius ∼70 arc min centered at the XRC of Coma. Details are available on the data reduction procedure [F. J. Lockman, K. Jahoda, D. McCammon, Astrophys. J. 302, 432 (1986)].
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9. On occasions when comparisons with stellar Lyman-α and quasar x-ray spectra could be made, the agreements among the different methods would suggest an error less than the nominal value [J. M. Dickey and F. J. Lockman, Annu. Rev. Astron. Astrophys. 28, 215 (1990); K. Willacy, A. Pedlar, D. Berry, Mon. Not. R. Astron. Soc. 261, 165 (1993); L. Danly, F. J. Lockman, M. R. Meade, B. D. Savage, Astrophys. J. Suppl. Ser. 81, 125 (1992); A. Laor, F. Fiore, M. Elvis, B. J. Wilkes, J. C. McDowell, Astrophys. J. 435, 611 (1994)].
10. On occasions when comparisons with stellar Lyman-α and quasar x-ray spectra could be made, the agreements among the different methods would suggest an error less than the nominal value [J. M. Dickey and F. J. Lockman, Annu. Rev. Astron. Astrophys. 28, 215 (1990); K. Willacy, A. Pedlar, D. Berry, Mon. Not. R. Astron. Soc. 261, 165 (1993); L. Danly, F. J. Lockman, M. R. Meade, B. D. Savage, Astrophys. J. Suppl. Ser. 81, 125 (1992); A. Laor, F. Fiore, M. Elvis, B. J. Wilkes, J. C. McDowell, Astrophys. J. 435, 611 (1994)].
11. On occasions when comparisons with stellar Lyman-α and quasar x-ray spectra could be made, the agreements among the different methods would suggest an error less than the nominal value [J. M. Dickey and F. J. Lockman, Annu. Rev. Astron. Astrophys. 28, 215 (1990); K. Willacy, A. Pedlar, D. Berry, Mon. Not. R. Astron. Soc. 261, 165 (1993); L. Danly, F. J. Lockman, M. R. Meade, B. D. Savage, Astrophys. J. Suppl. Ser. 81, 125 (1992); A. Laor, F. Fiore, M. Elvis, B. J. Wilkes, J. C. McDowell, Astrophys. J. 435, 611 (1994)].
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16. -3 count per second, which is barely detectable given our exposure and background level. In any case, there are no sources of this brightness and type in the vicinity of the XRC of Coma.
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18. M. Freyberg, personal communication.
19. This is because the particle background, which is not vignetted, accounts for only ∼0.7% of the total background.
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25. This is necessary, because the determination of abundances from the low spectral resolution of the DS and PSPC is problematic [F. Bauer and J. N. Bregeman, Astrophys. J. 457, 382 (1996)].
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27. We thank J. Vallerga, S. Snowden, C. McKee, and M. Lampton for helpful discussions. The work of C.-y.H. and S.B. was supported under NASA contract NAS5-30180. The National Radio Astronomy Observatory is operated by Association Universities, Incorporated, under a cooperative agreement with NSF.