TY - JOUR
T1 - The Ionized Gas and Nuclear Environment in NGC 3783. III. Detection of a Decreasing Radial Velocity in an Intrinsic Ultraviolet Absorber
AU - Gabel, Jack R.
AU - Michael Crenshaw, D.
AU - Kraemer, Steven B.
AU - Brandt, W. N.
AU - George, Ian M.
AU - Hamann, Frederick W.
AU - Kaiser, Mary Elizabeth
AU - Kaspi, Shai
AU - Kriss, Gerard A.
AU - Mathur, Smita
AU - Mushotzky, Richard F.
AU - Nandra, Klrpal
AU - Netzer, Hagai
AU - Peterson, Bradley M.
AU - Shields, Joseph C.
AU - Turner, T. J.
AU - Zheng, Wei
PY - 2003/9/20
Y1 - 2003/9/20
N2 - We report an intrinsic absorber with decreasing outflow velocity in the Seyfert 1 galaxy NGC 3783. This is the first detection of a change in radial velocity in an outflow associated with a Seyfert galaxy. These results are based on measurements from 18 observations with the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope, obtained between 2000 February and 2002 January. In two intervals separated by ∼13 and 9 months, the absorption lines in the kinematic component with highest outflow velocity exhibited mean redward velocity shifts of ∼35 and 55 km s1, respectively. The rate of velocity decrease was 2.2 ± 0.6 times more rapid in the second interval. No variations in absorption velocities were detected in the other kinematic components. We explore potential interpretations of the observed velocity shifts: radial deceleration of the UV absorber due to a change in either the speed or direction of motion of the outflow, and the evolution of a continuous flow across our line of sight to the emission source.
AB - We report an intrinsic absorber with decreasing outflow velocity in the Seyfert 1 galaxy NGC 3783. This is the first detection of a change in radial velocity in an outflow associated with a Seyfert galaxy. These results are based on measurements from 18 observations with the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope, obtained between 2000 February and 2002 January. In two intervals separated by ∼13 and 9 months, the absorption lines in the kinematic component with highest outflow velocity exhibited mean redward velocity shifts of ∼35 and 55 km s1, respectively. The rate of velocity decrease was 2.2 ± 0.6 times more rapid in the second interval. No variations in absorption velocities were detected in the other kinematic components. We explore potential interpretations of the observed velocity shifts: radial deceleration of the UV absorber due to a change in either the speed or direction of motion of the outflow, and the evolution of a continuous flow across our line of sight to the emission source.
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U2 - 10.1086/377342
DO - 10.1086/377342
M3 - Article
AN - SCOPUS:2442698743
SN - 0004-637X
VL - 595
SP - 120
EP - 126
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1 I
ER -