CHANDRA HIGH-RESOLUTION SPECTROSCOPY OF THE CIRCUMNUCLEAR MATTER IN THE BROAD-LINE RADIO GALAXY 3C 445

Journal Article · Fri Dec 10 00:00:00 EST 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/725/1/803· OSTI ID:21474429

Reeves, J N; Gofford, J ^[1]; Braito, V ^[2]; Sambruna, R ^[3]

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1. Astrophysics Group, School of Physical and Geographical Sciences, Keele University, Keele ST5 5BG (United Kingdom)
2. Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)
3. Code 662, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

We present evidence for X-ray line emitting and absorbing gas in the nucleus of the broad-line radio galaxy 3C 445. A 200 ks Chandra Low Energy Transmission Grating observation of 3C 445 reveals the presence of several highly ionized emission lines in the soft X-ray spectrum, primarily from the He- and H-like ions of O, Ne, Mg, and Si. Radiative recombination emission is detected from O VII and O VIII, indicating that the emitting gas is photoionized. The He-like emission appears to be resolved into forbidden and intercombination line components, which implies a high density of >10{sup 10} cm{sup -3}, while the oxygen lines are velocity broadened with a mean width of {approx}2600 km s{sup -1} (FWHM). The density and widths of the ionized lines indicate an origin of the gas on sub-parsec scales in the broad-line region. The X-ray continuum of 3C 445 is heavily obscured either by a partial coverer or by a photoionized absorber of column density N{sub H} = 2 x 10{sup 23} cm{sup -2} and ionization parameter log {xi} = 1.4 erg cm s{sup -1}. However, the view of the X-ray line emission is unobscured, which requires the absorber to be located at radii well within any parsec-scale molecular torus. Instead we suggest that the X-ray absorber in 3C 445 may be associated with an outflowing but clumpy accretion disk wind, with an observed outflow velocity of {approx}10, 000 km s{sup -1}.

• OSTI ID: 21474429
• Journal Information: Astrophysical Journal, Vol. 725, Issue 1; Other Information: DOI: 10.1088/0004-637X/725/1/803; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCRETION DISKS
EMISSION
OXYGEN
PHOTOIONIZATION
RADIO GALAXIES
RECOMBINATION
SOFT X RADIATION
SPECTROSCOPY
X-RAY GALAXIES
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
ELECTROMAGNETIC RADIATION
ELEMENTS
GALAXIES
IONIZATION
IONIZING RADIATIONS
NONMETALS
RADIATIONS
X RADIATION