[113.08] A Survey of Ly$\beta$, OVI and CIII Absorbers in the Low-Redshift IGM

AAS 203rd Meeting, January 2004
Session 113 Molecules and Atoms at High Z and Low Z
Poster, Thursday, January 8, 2004, 9:20am-4:00pm, Grand Hall

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[113.08] A Survey of Ly\beta, OVI and CIII Absorbers in the Low-Redshift IGM

C. W. Danforth, J. M. Shull, J. L. Rosenberg (University of Colorado)

We present the results of an ongoing survey of Ly\beta absorbers in the low-redshift (z<0.2) intergalactic medium (IGM) observed with the Far Ultraviolet Spectroscopic Explorer (FUSE). Approximately 30 extragalactic sight lines are presented, with a total of approximately 80 absorption systems. Each of these systems is associated with a previously-known Ly\alpha absorber with W\rm_Ly\alpha>80 mÅ\ observed with HST/STIS or HST/GHRS. By measuring the equivalent width of both lines, an accurate measure of the doppler parameter (b) and HI column density (N) can be found. In addition, some of these absorbers display absorption in higher Lyman lines, further constraining the physical parameters. The derived mean b-values is somewhat smaller than previously measured at 23±8 km s^-1 corresponding to an HI temperature of 33,000 K. Also available in the FUSE bandpass are the resonance transitions OVI \lambda\lambda1032,1038 and CIII \lambda977. These metal lines probe both the photoionized and warm-hot IGM and sample the metallicity and ionization conditions in the IGM.

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