Unusual Sombrero Galaxy: Why Astronomers Were Surprised by Its New Image (Photo)

The James Webb Space Telescope has observed the Sombrero Galaxy, also known as M104 and NGC 4594, in a new light, specifically in the mid-infrared spectrum. Astronomers did not observe the bright bulge at the center of the galaxy, which is visible in the optical light captured by the Hubble Telescope. Instead, the galaxy appears as a smooth disk surrounded by an outer ring composed of clumps of dust. Scientists believe that star formation in this galaxy has nearly come to an end, as reported by Space.

The Sombrero Galaxy got its name because it appears almost edge-on in visible light images, resembling the well-known wide-brimmed hat with a central protrusion. However, the new image reveals that the distinctive features of this galaxy have faded, and instead, the bright core of the galaxy, where a supermassive black hole resides, is encircled by a ring of dust clumps.

The Sombrero Galaxy is located 31 million light-years away from us and is the most massive spiral galaxy within a radius of 100 million light-years from Earth. The total mass of all the stars in this galaxy is estimated to be 260 billion solar masses, which is nearly five times greater than the mass of the Milky Way.

Given this, one might assume that the M104 galaxy is experiencing a vigorous formation of new stars, but that is not the case. Observations have shown that stars in this galaxy form four times slower than in the Milky Way.

When stars die, they leave behind dust, which then accumulates around the regions where new stars are born. The Webb Telescope is capable of seeing through the bright light of stars and detecting cold dust. Thus, the well-known bulge of the Sombrero Galaxy has disappeared in the new image, revealing only the dust-rich outer ring of the galaxy.

To create stars, not only dust but also gaseous molecular hydrogen is required. Dust helps keep hydrogen cold so that gravitational compression of molecular clouds can lead to star formation. However, the rate of new star formation in the Sombrero Galaxy indicates that there is little molecular hydrogen left within it.

Astronomers believe that the prominent bright bulge visible in Hubble Telescope images was likely formed billions of years ago during a massive surge of new star formation. As a result, most of the hydrogen was depleted, and currently, stars are only forming in the outer dust ring.

The M104 galaxy is relatively distant from other galaxies, meaning that interactions with them cannot provide additional fuel for new star creation.