(ORDO NEWS) — Using the Subaru Telescope and the Canadian-French-Hawaiian Telescope (CFHT), an international team of astronomers observed an ultra diffusion galaxy known as F8D1.
The observation campaign has revealed a huge tidal stream emanating from this galaxy.
Ultra Diffuse galaxies (UDGs) are extremely low density galaxies. The largest UDGs are about the same size as the Milky Way, but have only about 1% visible stars.
Scientists still cannot explain why these large and dim galaxies are not torn apart by the tidal field of their parent clusters.
Located about 12 million light-years away in the M81 group (a group of galaxies in the constellations Ursa Major and Giraffe), F8D1 is the closest UDG galaxy to the Milky Way.
Its effective radius is about 8,150 light-years, and its luminosity is about 40 million suns.
Although F8D1 was discovered back in 1998, it has been rather poorly understood. A team of astronomers, led by Rokas Zemaitis of the University of Edinburgh, used Subaru’s Hyper Suprime-Cam (HSC) thermal imager and CFHT’s MegaCam thermal imager to study this galaxy, hoping to gain more information about its properties.
The observations revealed a giant stream of stars that extends from F8D1 to the northwest, towards the galaxies NGC 2976 and M81.
This feature can be seen on both sides of NGC 2976.
The stream bends about 0.8 arc minutes west of the main body at small radii and reverses direction at large radii, bending about 1.1 arc minutes east at a distance of 40-60 arc minutes. minutes.
The size of the tidal stream is estimated to be at least 195,000 light years. Given that it contains 30-36% of the main body’s light, this indicates that F8D1 is undergoing severe tidal disruption.
Astronomers suggest that the most likely cause of F8D1’s tidal disruption is the central galaxy M81.
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