Cosmic Origins Spectrograph Observations of Mrk 817

Type Conference Paper
Names Cynthia S. Froning, L. Winter, B. Keeney, C. Danforth, J. Green, J. Shull, B. Savage, J. Stocke, B. Welsh, A. Narayanan, K. Sembach, J. Scott, S. Penton
Proceedings Title Bulletin of the American Astronomical Society
Conference Name American Astronomical Society, AAS Meeting #215, #464.15
Volume 42
Pages 501
Date January 1, 2010
URL http://adsabs.harvard.edu/abs/2010AAS...21546415F
Library Catalog NASA ADS
Abstract We present FUV spectroscopy of Mrk 817 obtained with the Cosmic Origins Spectrograph as part of the HST Early Release Observation program after Servicing Mission 4. FUV (1135 - 1735 A) moderate resolution (R 20,000) spectra of Mrk 817 were obtained in two HST orbits. The high S/N ( 40) spectra cover 15 times the bandpass of the previous GHRS observations in 1/10th the observing time. Mrk 817 is a nearby (z=0.031) Seyfert 1.5 galaxy that exhibits a powerful outflow (v 4200 km/s) seen in neutral hydrogen and highly ionized transitions (OVI, NV, CIV). The sightline to Mrk 817 also passes through the large High Velocity Cloud Complex C, which is detected quite prominently in numerous UV absorption lines of both low-ionization gas (OI, SII, CII, SiII) and high ions (CIV, SiIV, SiIII, SiIV, etc). This HVC and others may provide a major reservoir of low-metallicity gas, falling inward from the Galactic halo to the disk. In this poster, we present early results from the COS observations of Mrk 817, including discussion of the time variability of the intrinsic outflow and on the properties of Complex C.
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