Eyes Wide Shut – The Bridge in Markarian’s Chain

This image depicts a small part of the Virgo Galaxy Cluster. Containing more than 2,000 galaxies around 30 to 50 million light years away, the Virgo Cluster exerts tremendous gravitational influence on its members and neighbors, including what astronomers call our own “Local Group” of galaxies. Current evidence suggests that eventually, the Virgo cluster will swallow up the Local Group.

The Virgo cluster is home to 16 galaxies listed in the Messier catalogue, but this image only contains one of them—Messier 86 (M86). The main focus of this image is portion of the spectacular formation of galaxies called Markarian’s Chain.

Markarian’s Chain is named for Benjamin Markarian, an Armenian astrophysicist who, in 1961, discovered that the group of aforementioned galaxies shared a common motion. Just adjacent to M86 on its left are “The Eyes”—two interacting galaxies catalogued as NGC 4435 (top) and 4438 (bottom).

While I’m certainly not the first to expose it, one of the things that is unusual about this image is that it reveals what is often referred to “The Bridge” between The Eyes and M86. This was discovered in 2007 at Kitt Peak by Jeffrey Kenney and his team using the Mayall four-meter telescope. The Bridge has been characterized as tidal stripping of hydrogen from galaxies that are interacting gravitationally.

The Bridge is extremely faint. To achieve this capture required 280 hours of time on the telescope using a specialized hydrogen filter. The exposure time for the rest of the image, however, still amounted to more than 120 hours, making this one of my most arduous projects.