THE SOFT X-RAY AND NARROW-LINE EMISSION OF Mrk 573 ON KILOPARSEC SCALES

We present a study of the circumnuclear region of the nearby Seyfert galaxy Mrk 573 using Chandra, XMM-Newton, and Hubble Space Telescope (HST) data. We have studied the morphology of the soft (< 2 keV) X-rays comparing it with the [O III] and H alpha HST images. The soft X-ray emission is resolved into a complex extended region. The X-ray morphology shows a biconical region extending up to 12 arcsec (4 kpc) in projection from the nucleus. A strong correlation between the X-rays and the highly ionized gas seen in the [O III]lambda 5007 angstrom image is reported. Moreover, we have studied the line intensities detected with the XMM-Newton Reflection Grating Spectrometer (RGS) and used them to fit the low-resolution EPIC/XMM-Newton and ACIS/Chandra spectra. The RGS/XMM-Newton spectrum is dominated by emission lines of C vI, O vII, O vIII, Fe xvII, and Ne Ix, among other highly ionized species. A good fit is obtained using these emission lines found in the RGS/XMM-Newton spectrum as a template for Chandra spectra of the nucleus and extended emission, coincident with the cone-like structures seen in the [OIII]/H alpha map. The photoionization model Cloudy provides a reasonable fit for both the nuclear region and the cone-like structures showing that the dominant excitation mechanism is photoionization. For the nucleus the emission is modeled using two phases: a high ionization [log (U) = 1.23] and a low ionization [log (U) = 0.13]. For the high-ionization phase the transmitted and reflected components are in a 1: 2 ratio, whereas for the low ionization the reflected component dominates. For the extended emission, we successfully reproduced the emission with two phases. The first phase shows a higher ionization parameter for the northwest (log (U) = 0.9) than for the southeast cone (log (U) = 0.3). Moreover, this phase is transmission dominated for the southeast cone and reflection dominated for the northwest cone. The second phase shows a low-ionization parameter (log (U)= -3) and is rather uniform for northwest and southeast cones and equally distributed in reflection and transmission components. In addition, we have also derived the optical/infrared spectral energy distribution (SED) of the nucleus from high spatial resolution images of Mrk 573. The nuclear optical/infrared SED of the nucleus has been modeled by a clumpy torus model. The torus bolometric luminosity agrees very well with the active galactic nucleus (AGN) luminosity inferred from the observed hard X-ray spectrum. The optical depth along the line of sight expected from the torus modeling indicates a high neutral hydrogen column density in agreement with the classification of the nucleus of Mrk 573 as a Compton-thick AGN.