TY - JOUR
T1 - X-ray imaging of the Seyfert 2 galaxy Circinus with Chandra
AU - Sambruna, Rita M.
AU - Brandt, W. N.
AU - Chartas, G.
AU - Netzer, Hagai
AU - Kaspi, S.
AU - Garmire, G. P.
AU - Nousek, John A.
AU - Weaver, K. A.
N1 - Funding Information:
We are grateful to the ACIS and HETGS teams, who made these observations possible, and to Eric Feigelson for a critical reading of the manuscript and assistance. We acknowledge the financial support of NASA grant NAS8-38252 (R. M. S.; G. P. G.: PI), NASA LTSA grant NAG5-8107 (W. N. B., S. K.), and the Israel Science Foundation (H. N.).
PY - 2001/1/1
Y1 - 2001/1/1
N2 - We present results from the zero-order imaging of a Chandra High-Energy Transmission Grating Spectrometer observation of the nearby Seyfert 2 galaxy Circinus. Twelve X-ray sources were detected in the Advanced CCD Imaging Spectrometer-S (ACIS-S) image of the galaxy, embedded in diffuse X-ray emission. The latter shows a prominent (∼18″) soft "plume" in the northwest direction, coincident with the [O III] ionization cone. The radial profiles of the brightest X-ray source at various energies are consistent with an unresolved (FWHM ∼ 0″.8) component, which we identify as the active nucleus, plus two extended components with FWHM ∼ 2″.3 and 18″, respectively. In a radius of 3″, the nucleus contributes roughly the same flux as the extended components at the softest energies (≲2 keV). However, at harder energies (>2 keV), the contribution of the nucleus is dominant. The zero-order ACIS spectrum of the nucleus exhibits emission lines at both soft and hard X-rays, including a prominent Fe Kα line at 6.4 keV, showing that most of the X-ray lines previously detected with ASCA originate in a compact region (≲15 pc). Based on its X-ray spectrum, we argue that the 2″.3 extended component is scattered nuclear radiation from nearby ionized gas. The large-scale extended component includes the emission from the northwest plume and possibly from the outer starburst ring.
AB - We present results from the zero-order imaging of a Chandra High-Energy Transmission Grating Spectrometer observation of the nearby Seyfert 2 galaxy Circinus. Twelve X-ray sources were detected in the Advanced CCD Imaging Spectrometer-S (ACIS-S) image of the galaxy, embedded in diffuse X-ray emission. The latter shows a prominent (∼18″) soft "plume" in the northwest direction, coincident with the [O III] ionization cone. The radial profiles of the brightest X-ray source at various energies are consistent with an unresolved (FWHM ∼ 0″.8) component, which we identify as the active nucleus, plus two extended components with FWHM ∼ 2″.3 and 18″, respectively. In a radius of 3″, the nucleus contributes roughly the same flux as the extended components at the softest energies (≲2 keV). However, at harder energies (>2 keV), the contribution of the nucleus is dominant. The zero-order ACIS spectrum of the nucleus exhibits emission lines at both soft and hard X-rays, including a prominent Fe Kα line at 6.4 keV, showing that most of the X-ray lines previously detected with ASCA originate in a compact region (≲15 pc). Based on its X-ray spectrum, we argue that the 2″.3 extended component is scattered nuclear radiation from nearby ionized gas. The large-scale extended component includes the emission from the northwest plume and possibly from the outer starburst ring.
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U2 - 10.1086/318067
DO - 10.1086/318067
M3 - Article
AN - SCOPUS:0035217735
SN - 0004-637X
VL - 546
SP - L9-L12
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1 PART 2
ER -