2009/11/02 by Maxwell Moe, Nahum Arav, Manuel A. Bautista +1 · 11 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Kinetic energy #Line (geometry) #Luminosity #Outflow #Photoionization #Quasar #Redshift #Spectral energy distribution #Spectral line #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.1088/0004-637x/706/1/525
published as Astrophys.J.706:525-534,2009 · 28 pages, 7 figures, 4 tables, published in Astrophysical Journal
openalex publication_date 2009/11/02 · arxiv created 2009/11/18 · arxiv updated 2014/11/20 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We present a detailed analysis of the Astrophysical Research Consortium 3.5 m telescope spectrum of QSO SDSS J0838+2955. The object shows three broad absorption line (BAL) systems at 22,000, 13,000, and 4900 km s −1 blueshifted from the systemic redshift of z = 2.043. Of particular interest is the lowest velocity system that displays absorption from low-ionization species such as Mg ii , Al ii , Si ii , Si ii *, Fe ii , and Fe ii *. Accurate column densities were measured for all transitions in this lowest velocity BAL using an inhomogeneous absorber model. The ratio of column densities of Si ii * and Fe ii * with respect to their ground states gave an electron number density of log n e (cm −3 ) = 3.75 ± 0.22 for the outflow. Photoionization modeling with careful regards to chemical abundances and the incident spectral energy distribution predicts an ionization parameter of log U H = −1.93 ± 0.21 and a hydrogen column density of log N H (cm −2 ) = 20.80 ± 0.28. This places the outflow at 3.3 +1.5 −1.0 kpc from the central active galactic nucleus (AGN). Assuming that the fraction of solid angle subtended by the outflow is 0.2, these values yield a kinetic luminosity of (4.5 +3.1 −1.8 ) × 10 45 erg s −1 , which is (1.4 +1.1 −0.6 )% the bolometric luminosity of the QSO itself. Such large kinetic luminosity suggests that QSO outflows are a major contributor to AGN feedback mechanisms.