The Hubble team has released a stunning image of an intermediate spiral galaxy called NGC 3227 and its companion, the dwarf elliptical galaxy NGC 3226.
Collectively known as Arp 94 and Holm 187, the galaxy pair lies some 50 million light-years away in the constellation of Leo.
A close look at the area between NGC 3226 and NGC 3227 reveals faint tidal streams of gas and dust that link the pair in their gravitational dance.
NGC 3226 is considered something between a youthful blue galaxy and an old red galaxy.
The colors refer to the predominantly galactic blue light radiated by giant, young stars — a telltale sign of recent star formation — and the reddish light cast by mature stars in the absence of new, blue ones.
NGC 3226 illuminates how galaxies accruing fresh gas and dust can bloom with new stars or have their stellar factories close shop, at least temporarily.
Intriguingly, ultraviolet and optical light observations suggest that NGC 3226 may have produced more stars in the past, leading to its current intermediate color, somewhere between red and blue.
Spanning about 90,000 light-years, similar in size to the Milky Way, NGC 3227 is a Seyfert galaxy, a type of galaxy with an active galactic nucleus (AGN).
“Seyfert galaxies hold supermassive black holes at their cores,” Hubble astronomers said.
“As matter spirals into the black hole, it releases vast amounts of radiation along the black hole’s axis of rotation, giving the galaxy its active nucleus.”
Hubble looked at NGC 3227 and 3226 as part of a program to measure black hole masses by observing the dynamics of gas at the centers of bright cluster galaxies.
“The color red in this image represents both visible red and near infrared wavelengths of light,” the researchers noted.
Source link: https://www.sci.news/astronomy/hubble-arp-94-10843.html