My Favorite Newsletter: [New post] Astronomy Photo of the Day: 2/3/15

2015년 2월 3일 화요일

[New post] Astronomy Photo of the Day: 2/3/15 — NGC 4217

New post on From Quarks to Quasars

Astronomy Photo of the Day: 2/3/15 — NGC 4217

by Jaime Trosper

Image Credit: ESA/Hubble & NASA (Acknowledgement: R. Schoofs)

This galaxy, called NGC 4217, is both detailed and extremely beautiful. In a new image taken by the Hubble Space Telescope, we see the galay in unprecedented detail. It's spiral in nature, and from this vantage point, we can make out many key points that would otherwise go unnoticed from farther away, particularly the extraplanar dust lanes (seen in brown), which are woven above and below the galaxy's plane. According to NASA:

[box style="0"] These tentacle-like filaments are visible in the Hubble image only because the contrast with their surroundings is so high. This implies that the structures are denser than their surroundings. The image shows dozens of dust structures some of which reach as far as 7,000 light-years away from the central plane. Typically the structures have a length of about 1,000 light-years and are about 400 light-years in width.

Some of the dust filaments are round or irregular clouds, others are vertical columns, loop-like structures or vertical cones. These structures can help astronomers to identify the mechanisms responsible for the ejection of gas and dust from the galactic plane of spiral galaxies and reveal information on the transport of the interstellar medium to large distances away from galactic disks.

The properties of the observed dust structures in NGC 4217 suggest that the gas and dust were driven out of the mid-plane of the galaxy by powerful stellar winds resulting from supernovae — explosions that mark the deaths of massive stars.

[Reference: NASA] [/box]

NGC 4217 can be found about 60 million light-years away from Earth in the constellation of Canes Venatici. Astronomers suspect that it may also be a companion of the neighboring galaxy, Messier 106.