ESO 148-2
ESO 148-2 known as ESO 148-IG002 and IRAS 23128-5919, is a galaxy merger located in the constellation of Tucana. It is located 642 million light years from Earth and is classified a Wolf-Rayet galaxy as well as an ultraluminous infrared galaxy.
Characteristics
A late-stage merger involving two colliding disk galaxies, ESO 148-2 has a distorted main body structure that is similar to the Antennae galaxies. Its appearance takes a form of an owl taking flight with curved large tidal tails representing as wings, made from both stars and gas. The black hole in ESO 148-2 has an estimated mass of 4.4 x 107 Mʘ.ESO 148-2 is also a bright galaxy with a star formation rate of 149 Mʘ yr−1 and an infrared luminosity of LFIR =1011.71 Lʘ. This infrared luminosity is interpreted as radiation emitting from dust emissions via intense heating of its star formation regions. In the regions of the galaxy, there are type N Wolf-Rayet stars emitting N III λ4641 and He II λ4686 emission, making them the brightest subtype. The H II regions of ESO 148-2 are dominated by star formation with an estimated metallicity rate of 9.09 ± 0.03. Furthermore it has a point-like source, with both of the thermal and de-absorbed power law components in its spectrum having a luminosity of ~ 1.5 x 1041 and ~ 2.7 x 1042 erg s−1 respectively.
ESO 148-2 has two nuclei with a projected separation of ~ 4.5 arcsec. The nuclei in ESO 148-2 are found close to each other. Each of them have different properties. The northern nucleus contains a velocity dispersion value agreeing with star formation and emission line ratios in alignment of both LINERS and H II regions. The southern nucleus on the other hand, is three times more luminous at 24 μm and harbors an active galactic nucleus detected by both infrared and X-rays with an absorption-corrected luminosity of logL2-10 = 42.38+0.24-0.28. In the supermassive black hole of the southern nucleus, new stars are born through powerful galactic outflows.
According to Johnson UBVJHKL and spectroscopy photometry, as well as CCD-imaging, the central region of ESO 148-2 exhibits firm emission lines with a full width at half maximum of 600 kilometers per seconds. These emission lines are found blueshifted by 320 km/s to the absorption spectrum.