Messier 87 (M87) is a massive elliptical galaxy located in the Virgo constellation. It was discovered in 1781 by French astronomer Charles Messier and is listed as the 87th object in the Messier catalog. Located approximately 53.5 million light-years from Earth, this galaxy is one of the largest and brightest members of the Virgo Cluster. It is particularly significant in astrophysical research due to the supermassive black hole at its center and the relativistic jet emitted from it.

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Physical Characteristics

Structure and Size

Messier 87 belongs to the class of classical elliptical galaxies and lacks a distinct disk structure. Containing hundreds of billions of stars, M87 is estimated to have a diameter of about 120,000 light-years.

The stars it hosts are mostly old and metal-poor, giving the galaxy an overall yellowish-white hue. It lacks spiral arms or intense star-forming regions, resulting in a low star formation rate.

Globular Cluster Population

The number of globular star clusters in M87 is extraordinary. While the Milky Way contains about 150 globular clusters, M87 hosts between 12,000 and 15,000. These clusters play a significant role in understanding the distribution of dark matter, which constitutes a large portion of the galaxy’s mass.

Mass and Dark Matter

The total mass of M87 is estimated to be around 2.7 trillion solar masses. Observations indicate that most of the galaxy’s total mass is not from visible matter but from dark matter. The presence of dark matter is supported by the fact that stars in the outer regions of the galaxy rotate at higher speeds than expected.

Supermassive Black Hole and Jet Formation

The most striking feature of M87 is the supermassive black hole at its center. Imaged directly in 2019 through the Event Horizon Telescope (EHT) collaboration, this black hole enabled humanity to observe a black hole’s "shadow" for the first time. This observation marked a milestone in directly testing general relativity.

The mass of the black hole is approximately 6.5 billion solar masses.
The relativistic jet emanating from this black hole can be observed in radio and X-ray wavelengths.
The jet stretches to about 5,000 light-years in length, and the plasma within it travels at nearly the speed of light.

The mechanism of jet formation is likely related to the black hole’s rotation and the surrounding magnetic fields. Such jets are a hallmark of active galactic nuclei (AGN) and play a role in transporting high-energy particles beyond the galaxy.

Interaction with the Virgo Cluster and Surroundings

M87 is the central and largest galaxy of the Virgo Cluster, which contains about 2,000 galaxies. Due to its mass and gravitational influence, it is believed to draw in and disrupt smaller galaxies. Its interactions with the intergalactic medium are studied through the distribution of hot gas observed in X-ray observations.

This galaxy is also a massive radio source located at the center of the cluster and is a key target in radio astronomy.

Scientific Importance

Messier 87 plays a critical role in understanding the evolution of massive structures on a cosmological scale. It is a fundamental research subject in areas such as:

The formation and evolution of supermassive black holes
Jet dynamics and magnetohydrodynamic processes
Galaxy clusters and the distribution of dark matter
The evolution of stellar populations

In addition, M87 contributed to the observational confirmation of general relativity through EHT observations testing the curvature of spacetime around a black hole.

Messier 87 is a galaxy of great scientific significance in astrophysics, spanning a wide range of research topics from black hole physics to galactic evolution.

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Thanks to its supermassive black hole and intergalactic interactions, M87 continues to be a key observational object in understanding the large-scale structure of the universe.

Messier 87 (M87)