100 likes | 183 Views
NGC 4151. Mass Outflows from AGN in Emission and Absorption. Mike Crenshaw (Georgia State University) Steve Kraemer (Catholic University of America) Jack Gabel (University of Colorado).
E N D
NGC 4151 Mass Outflows from AGN in Emission and Absorption Mike Crenshaw (Georgia State University) Steve Kraemer (Catholic University of America) Jack Gabel (University of Colorado)
Six HST/STIS echelle observations (0.2'' x 0.2'’) of central emission-line knot (including nucleus): 1999 July - 2002 May • Simultaneous HST, FUSE, and CXO observations in 2002 May (see Kraemer et al. 2005, ApJ, 633, 693 for more on X-ray observations) UV/X-ray Observations of NGC 4151 NGC 4151 [O III] Image
STIS observations taken at moderate to low flux levels History of UV Continuum Variations (~21 Years) IUE: black pluses HUT: red diamonds FOS: green triangles STIS: blue x’s
Absorption Components in STIS and FUSE Spectra • A, C, D+E, E are intrinsic; B is Galactic; F, F are host galaxy. • D+E (vr = -500 km s-1) responsible for bulk of UV and X-ray absorption.
Variability in C IV Region (Kraemer et al. 2006, in preparation) • D+E varies strongly in the low-ionization lines (e.g., Si II) • D+E in 2002 is much weaker than expected from ionization changes
Variability of D+E Absorption (1999 - 2002) • EW of low-ionization lines generally anti-correlated with continuum ionization changes (high-ionization lines are saturated) • Low EW in last observation indicates change in column density. transverse motion: vT ≥ 1250 km s-1
blue - narrow green - intermediate Emission-Line Profiles at Low Flux Levels He II • He II profile has two components (broad component not detected): narrow: 260 km s-1 FWHM, intermediate: 1150 km s-1 FWHM
blue - narrow green - intermediate red - broad Emission-Line Profiles at Low Flux Levels C IV • Fit to C IV profile using He II components (plus broad-line profile) • D+E absorbs intermediate component self absorption? (P-Cygni like) likely the absorber in emission
Photoionization Models: 2002 STIS, FUSE, CXO Observations • D+Eb responsible for most of the metastable C III. distance ≈ 0.1pc • D+Ea is responsible for high-ionization UV lines and most of the X-ray absorption, and must screen D+Eb distance ≤ 0.1pc • D+Ec needed for low Clos of P V, etc. (distance unknown)
Conclusions • The outflowing UV absorbers in NGC 4151 vary as a result of both changing ionization and motion across the line of sight. • Component D+E is responsible for the bulk of the UV and X-ray absorption, and has several physical subcomponents (a-c). • Most of D+E is only ~0.1 pc from the central source (compared to tens of pcs for many UV/X-ray absorbers). • D+E (at vr = 500 km s-1) has a transverse velocity ≥ 1250 km s-1, similar to the rotation velocity at 0.1 pc (720 km s-1). • We have detected D+E in emission, which yields a global covering factor of 0.35 - 0.8. • This component provides the best case for a rotating accretion disk wind in a Seyfert galaxy.