The surprising turbulent past of metal rich halo of Messier 104 represents Messier 104, a lenticular galaxy located 28 million light years away in the constellation Virgo. Messier 104 is a lenticular galaxy located 28 million light years away in the constellation Virgo. Now it has a new chapter in its history.
An expanded halo of metal-rich stars, a sign of the expected metal-poor stars seen under the influence of other galaxies. This Hubble image shows Messier 104. Image from NASA / ESA / Hubble Heritage Team / STScI / AURA.
Astronomer and team member of the Space Telescope Science Institute, Drs. Paul Goudfreuse said: “Also known as the Sombrero galaxy, Messier 104 has always been a kind of strange galaxy, which makes it interesting.” I watched the galaxy using the NASA / ESA Hubble Space Telescope.
He added: “Hubble’s measure of metallicity (that is, the abundance of heavy elements in the stars) is another indication that Messier 104 has much to teach us about the assembly and evolution of galaxies.”
The results suggest an equally surprising possibility of major mergers in the galaxy’s past, although Messier 104’s majestic structure is not evidence of recent disruption. “The absence of metal-poor stars was a big surprise,” said Dr. Gaudfreuise, and the abundance of metal-rich stars only added to the mystery.
On the left is an image of Messier 104 that includes a very bright portion of the greeting outside its bright disk and bump. Hubble represented two areas in the halo (one of which is represented by a white box). The images are captured in the right zoom to show the level of detail of the Hubble.
Orange Box, a small subset of the Hubble scene, which includes countless Halo stars. The density increases near the disk of the galaxy (blue box below). Each frame consists of a bright circular cluster of stars, many of which are found in the halo of the galaxy.
The halo of Messier 104 had more metal-rich stars than expected, but even more strange was the absence of older and metal-poor stars that are commonly found in manifestations of massive galaxies.
However, many spherical clusters have metal-poor stars. A possible explanation of the macular characteristics of Messier 104 is that it is the product of a fusion of massive galaxies thousands of millions of years ago, although the smooth appearance of the galaxy’s discs and halos showed no signs of a disruption. so big.
Image from NASA / Digitized Sky Survey / P. Goudfrooij, STScI / Hubble Heritage Team / STScI / AURA. Astronomers in the halo of a galaxy expect to find previous generations of stars with less massive elements than the crowded star cities present on the galaxy’s main disk.
The elements are created through the process of the stellar life cycle, and the more time the stars spend in the galaxy this cycle, the more gases rich in elements and highly metallic stars are formed from that gas. These small, highly metallic stars are usually found on the main disk of the galaxy, where stellar populations are dense, or so conventional wisdom says.
The facts that complain is the presence of many clusters of spherical stars older and poor in metals. These older and metal-poor stars are expected to finally come out of their clusters and become part of the normal star halo, but this process seems to have been inefficient in Messier 104.
Astronomers compared their results with recent computer simulations to see what could be the origin of such unexpected measurements of metals in the galaxy’s halo. The results also challenged expectations, indicating that the unaffected Messier 104 had suffered events or mergers that occurred billions of years earlier.
Unlike our galaxy, the Milky Way, which is believed to have swallowed many smaller satellite galaxies in billions of years in the so-called “nominal” accumulation, a larger accumulation is a fusion of two or more equally massive galaxies that were enriched in later generations. They are high-metal stars.
Satellite galaxies have only fewer metal stars that were largely hydrogen and helium from the Big Bang. The heavier elements would be cooked in stellar interiors through nucleosynthesis and incorporated into the stars of the later generation.
This process was not effective in dwarf galaxies, such as those in our Milky Way, and was dominant in larger and more evolved galaxies. The results of Messier 104 are surprising because its smooth disc shows no signs of interruption.
In comparison, many conflicting galaxies, such as iconic antenna galaxies, derive their names from the distortions of their spiral arms due to their tidal contact forces.
Mergers of similar massive galaxies generally encompass large, smooth elliptical galaxies, which have been billions of years with widespread disclosure. But Messier 104 has never been compatible with the traditional definition of a spiral or elliptical galaxy. It is somewhere in the middle of a hybrid.
The study was published in the Astrophysical Journal.