X-ray imaging of the Seyfert 2 galaxy Circinus with Chandra

Rita M. Sambruna, W. N. Brandt, G. Chartas, Hagai Netzer, S. Kaspi, G. P. Garmire, John A. Nousek, K. A. Weaver

Research output: Contribution to journalArticlepeer-review

31 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)L9-L12
JournalAstrophysical Journal
Issue number1 PART 2
StatePublished - Jan 1 2001

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'X-ray imaging of the Seyfert 2 galaxy Circinus with Chandra'. Together they form a unique fingerprint.

Cite this