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Explanation: How far do magnetic fields extend up and out of spiral galaxies? For decades astronomers knew only that some spiral galaxies had magnetic fields. However, after NRAO's Very Large Array (VLA) radio telescope (popularized in the movie Contact) was upgraded in 2011, it was unexpectedly discovered that these fields could extend vertically away from the disk by several thousand light-years. The featured image of edge-on spiral galaxy NGC 5775, observed in the CHANG-ES (Continuum Halos in Nearby Galaxies) survey, also reveals spurs of magnetic field lines that may be common in spirals. Analogous to iron filings around a bar magnet, radiation from electrons trace galactic magnetic field lines by spiraling around these lines at almost the speed of light. The filaments in this image are constructed from those tracks in VLA data. The visible light image, constructed from Hubble Space Telescope data, shows pink gaseous regions where stars are born. It seems that winds from these regions help form the magnificently extended galactic magnetic fields.
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NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: magnetic field - spiral galaxy
Publications with words: magnetic field - spiral galaxy
See also:
- APOD: 2025 September 4 Á NGC 4565: Galaxy on Edge
- APOD: 2025 August 28 Á Galaxies, Stars, and Dust
- APOD: 2025 August 22 Á A Tale of Two Nebulae
- APOD: 2025 August 19 Á Giant Galaxies in Pavo
- APOD: 2025 August 18 Á NGC 1309: A Useful Spiral Galaxy
- APOD: 2025 July 30 Á Coronal Loops on the Sun
- APOD: 2025 July 4 Á NGC 6946 and NGC 6939