The Bright X-Ray Source in NGC 3413

Abstract

The emission-line dwarf galaxy NGC 3413 is known to host a bright X-ray source near its optical center. The 0.3-10 keV luminosity of this source is estimated to be approximately 10(39) erg s(-1), potentially qualifying it as an ultraluminous X-ray source (ULX). A recent X-ray Multi-Mirror Mission-Newton observation suggests that the source is not point-like, and instead is more likely a composite of point-like sources with extended and/or diffuse emission. The spectral and temporal features of the bright region are similar to those associated with the so-called broadened disk state of ULXs. Based on a multicolor blackbody spectral fit, we estimate the mass of the bright source to be in the range 3-20M(circle dot). Potential optical counterparts are also explored with the aid of available Sloan Digital Sky Survey and PanStars data.