Suzaku Studies of Wide-Band Spectral Variability of the Bright Type I Seyfert Galaxy Markarian 509

Abstract

The Type I Seyfert galaxy Markarian 509 was observed with Suzaku in 2010 November, for a gross time span of 2.2 days. Timing and spectral properties of the 0.5-45 keV X-rays, detected with the XIS and HXD, consistently revealed the presence of a soft spectral component that remained constant while the total Xray intensity varied by ±10%. This stable soft component, found in the 0.5-3.0 keV range, was interpreted as a result of thermal Comptonization in a corona with a temperature of ∼ 0.5 keV and an optical depth of ∼ 18. The time-avearged 0.5-45 keV Suzaku spectrum was reproduced successfully, as a combination of this thermal Comptonization component, a harder power-law of photon index ∼ 1.8, moderate reflection, and an iron K-emission line. By analyzing four archival Suzaku datasets of the same object obtained in 2006, the thermal Comptonization component, which was stable during the 2.2 day pointing in 2010, was found to vary on time scales of a few weeks, independently of the power-law component. Implications of these results are discussed in terms of the "multi-zone Comptonization" view, obtained with Suzaku from the black hole binary Cygnus X-1.

X-Ray and Optical Correlation of Type I Seyfert NGC 3516 Studied With Suzaku and Japanese Ground-Based Telescopes

“…It has a redshift of z = 0.00884, which corresponds to a distance of D = 41. Maoz et al (2002), to exhibit a poor X-ray and optical correlation, the result will change if we properly decompose its X-ray continuum using the technique of Noda et al (2011b, because NGC 3516 is one of the prototypical objects to which this method has been successfully applied (Noda et al 2013a). Unless otherwise stated, errors shown in tables and figures in the present paper refer 1σ errors.…”

“…The presence of these different primary X-rays may represent the presence of several distinct types of coronae with different electron temperatures and optical depths. Furthermore, in order to explain a soft X-ray excess in a low energy band below ∼3 keV, a soft thermal Comtonization continuum has been suggested, invoking yet another corona (e.g., Mehdipour et al 2011;Noda et al 2011b, 2013c, Jin et al 2013. The reality of this third corona, however, needs further examination, because the soft excess may alternatively be modeled in terms of relativistically smeared ionized reflection (e.g., Fabian et al 2004) or absorption by disk winds (e.g., Gierliński & Done 2004).…”

Detection of Coronal Magnetic Activity in nearby Active Supermassive Black Holes

“…OBSERVATIONS 2.1. Target objects IC 4329A is a southern Seyfert 1.2 galaxy at z = 0.0161 (Willmer et al 1991) whose central black hole mass is ∼ 1.2×10 8 M (Nikolajuk et al 2004;Markowitz 2009). The host galaxy is an edge-on spiral galaxy in a pair with IC 4329 separated by ∼ 3 arcmin.…”

Suzaku observations of spectral variations of the ultra-luminous X-ray source Holmberg IX X-1

“…However, this type of "thick and cool" coronae are being discovered in various accreting objects that are shining considerably below their Eddington limits. For example, Noda et al (2011) concluded that the "soft excess" in Active Galactic Nuclei can be interpreted, at least in some cases, as the highest end of the THC continuum; a representative Type I Seyfert, Mrk 509, had a corona with a temperature of Te = 0.49 keV and an optical depth of 17.6. Another example is a report by Sugizaki et al (2013) that the neutron-star binary MAXI J0556-332 harbored a corona of τ = 8 − 10 and Te = 1.5 − 3 keV, during its High/Soft (but still sub-Eddington) state.…”