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Hubble’s Magnetic Monster

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The Power of Magnetic Fields in Space

Yesterday this amazing picture came rumbling through the Intarwebs from the folks at Hubble Space Telescope. It’s from the Advanced Camera for Surveys and shows the galaxy NGC 1275 seemingly surrounded by what looks like a spiderweb of stuff.

Now, there’s a lot going on here, so let’s break it down. First, the galaxy is in the center of the Perseus Cluster of galaxies, and the whole region is permeated with hot gas — REALLY hot — around 100 million degrees. The red stringy things are filaments of cooler hydrogen gas and they’re threaded on magnetic field lines that extend throughout the region.

Magnetic field lines?  Yes, this is indeed true. The actions of a supermassive black hole and its associated jet at the core of the galaxy are the source of very strong magnetic fields that extend quite far out from the core. Gas near the center of the galaxy gets superheated by all the hoopla surrounding the black hole and jet, and that blows bubbles of material out into surrounding space. Those expanding bubbles plow into cooler regions of hydrogen gas, and the expansion carries some of that gas out along with it. The red filaments are the hydrogen gas that looks like it’s draped on the magnetic field lines. Those filaments are actually a very important clue to astronomers. They are the biggest visible-light evidence for some “invisible” (i.e. not visible to our eyes) interactions between NGC 1275’s central black hole and the hot gas that permeates the surrounding interstellar and intergalactic spaces.

Now, the filaments look really delicate, and you’d think that the huffing and puffing of material blasting out from the center of the galaxy via the jet would destroy the hydrogen gas threads. What’s saving them are the magnetic fields. Those lines of force hold the gas in place and help it resist the outward blasts from the core of the galaxy. They also keep the gas from clumping up to form newborn stars, making them a disruptive as well as a unifying force.

For anybody who thought that intergalactic space might be empty and boring, this image and another one taken with multiple instruments (left), reveals just how frenetic the environment in galaxy clusters can be.

While we may not be able to see those magnetic fields, images like these show us the effects that such fields have on the ordinary matter they thread through.

For more information, surf on over to the Space Telescope Science Institute’s HubbleSite page.

astronomy, astronomy news, hubble space telescope

Reaching a Cosmic Milestone

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Hubble “on the Road” for 18 years and Counting

Hubble’s 100,000 orbit of planet Earth occurred last week on August 8, more than 18 years after the telescope’s launch and 4.3 billion orbital kilometers of travel. To celebrate, astronomers took the long-awaited chance to to grab a stunning image of a starbirth region near a star cluster in the Milky Way Galaxy.

It was also 18 years ago this month that I was working as a sort of “junior” member of one HST’s instrument teams. We’d had a pretty rough summer that year, what with the discovery of spherical aberration in the telescope’s main mirror and a host of assorted difficulties that, in retrospect, could plague any orbiting mission at the time. It was not a great time, but even then, there were solutions on the drawing board that would allow us to get the maximum amount of science from the telescope. And, as most everybody knows, the telescope survived and has gone on to greater and greater things, all due to the technical ingenuity of a lot of really dedicated people.

Indeed, that August, despite the ongoing press characterization of HST in the worst possible terms, scientists released an amazing image of Saturn (right), showing that the telescope could indeed do decent science, as hobbled as it was. I think that was about the time I decided that somehow I was going to write a book about HST and talk about what was really happening with the orbiting observatory. It took a few years, but I managed it, writing Hubble Vision (in two editions, both of them available from time to time) with great mutual support and enthusiasm of my advisor and co-author, John C. Brandt (who is retired now, but nonetheless still stirring the astronomy pot from his perch at the University of New Mexico (where he has been teaching and doing research even as he takes lots of time out for hiking and cruises)). After we got done with those two, we turned around and wrote a general astronomy book called Visions of the Cosmos that benefitted greatly from HST images (as well as some stunners from a bevy of space- and ground-based observatories).

It’s really kind of mind-blowing to look back on those times (which to me seem like they weren’t that long ago) and realize just how much this telescope has done; what it has contributed to astronomy research. Without its imaging and data, much of what we know about astronomy–in particular the distant universe–might still be hovering on the edges of detection. HST has spurred some advancements in detection and data-processing techniques, and seems also to have instigated some improvements that have benefitted ground-based technologies, too.

So, I propose a toast to our long-traveling HST, which is about to get its last and most wonderful upgrade in a few months. Long may it sail overhead, giving us unprecedented peeks across space and time!