A spiral that can beat you with two arms tied behind its back

By Phil Plait | May 4, 2012 6:30 am

Messier 106 is an elongated spiral galaxy, seen by us at a low angle, in the constellation of Canes Venatici (CANE-eez ven-AT-ih-sigh, the hunting dogs). It’s about 25 million light years away, give or take. That may sound far — 250 million trillion kilometers! — but for Hubble, that’s considered close. So if you take a stack of Hubble images of M106 and put them together, as amateur astronomer Andre vd Hoeven did, you get a lovely picture it!

[Click to galactinate and get access to a zoomable version — and you want to. I shrank the image considerably to get it to fit here. (UPDATE: there’s a HUGE version at Flickr.)]

M106 looks a bit odd to my eye. The overall structure is pretty typical for a two-armed spiral seen at this low angle, but still… those red spots mark the location of busy star formation. The hot young stars heat up their surrounding gas, and the hydrogen in them reacts by glowing. Usually you see star formation that intense over a large region of the galaxy, or a small region, but not somewhere in between like this.

Not being familiar with the galaxy, I looked it up, and found the image inset here (which I’ve rotated to better match the Hubble image above). Right away we see something really weird: there are two more arms invisible in the Hubble shot!

What the what?

The inset picture is a combination from a lot of telescopes and wavelengths: visible light (displayed as gold), infrared (red), radio (purple) and X-ray (blue). The visible and IR line up well with Hubble’s view, but the radio and X-ray clearly show those extra arms. X-rays are emitted by very hot gas — like, million degrees hot — and radio is emitted by gas with a strong magnetic field permeating it. That’s a hint about what’s going on. Another is that the core of the galaxy is very bright, glowing more fiercely than you’d expect from a normal galaxy.

That adds up to one thing: an actively feeding black hole in the galaxy’s heart. And it’s big: about 40 million times the mass of the Sun. Material from the galaxy is falling onto the black hole, and piling into a huge disk just outside the Final Plunge. This disk is incredibly hot, and for reasons still not entirely understood (but which involve intense magnetic fields) powers twin beams of energy and matter which blast out at high speed in opposite direction. These beams are slamming into and heating up the gas in the galaxy, and that’s what’s lighting up those extra arms. The beams are cone-shaped (think beams from a light house), which is why we only see some of that gas lit up.

Weirdly, the beams are blasting through the disk of the greater galaxy. Usually, the disk of the black hole is roughly aligned with the exterior galaxy itself, so the beams travel "up and down", right out of the galaxy, but clearly that’s not the case here! Also, judging from the power in those beams, if they were aimed at us the core of that galaxy would be really bright, and M106 would be a heckuva lot more famous than it already is. I wonder if it would be naked eye visible? It’s possible.

Funny. There’s hardly a hint of all that incredible energy blasting out, all that drama, in the Hubble image. As detailed and high-resolution as it is, it shows we still need as many eyes on the sky as can muster if we really want to uncover the secrets of the Universe.

Image credits: Hubble: Andre vd Hoeven & Adrian Zsilavec and Michelle Qualls/Adam Block/NOAO/AURA/NSF & enhanced with a ground-based image by Adam Block; X-ray:NASA/CXC/Univ. of Maryland/A.S. Wilson et al./Optical: Pal.Obs. DSS/IR: NASA/JPL-Caltech/Radio: NRAO/AUI/NSF

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CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

Comments (16)

  1. Related: What does that mean for all the planets in the path of the beams in that galaxy? In my completely unscientific wondering, if the black hole is arranged in such a way that the beams are crossing the galaxy like that wouldn’t that indicate that it is “tipped” over and is rotating in such a way that those bright spots you point out could be on the leading/trailing edge of the rotation? Could the rotation of a supermassive black hole at such an odd angle relative to the rest of the galaxy cause the gravity distortions expected to interact with the disc strangely?

    Unrelated: I gave Abbie crap about how Physics related stuff is a better subject than Biology during your talk due to the distinct lack of duck anatomy. Unfortunately, subsequent jokes have ruined my ability to look at spiral galaxies without remembering Darrel’s talk…

  2. Dwight

    Two beams blasting out through the galactic disk?
    Sort of makes me wonder… if there is life in that galaxy, is it subjected to periodic death rays leading to mass extinctions?

  3. Pete Jackson

    Incredible image, zooming in to so many huge associations of hot, young stars. Hubble rocks!

  4. Charles

    Shouldn’t it be “KHAN-ays way-NOT-ee

  5. Tara Li

    Is the black hole in the center of that galaxy just tipping over because it’s gyroscopically unstable, like they say Earth would be without the Moon? But if that’s the case – why does everyone look for an impactor to have tipped over Uranus, which is without a significant (relatively) moon to stabilize it?

  6. Charles

    Grr, stupid browser posting my comment prematurely.

    Shouldn’t it be “KHAN-ess way-NOT-ih-chee”? Or is there a guidebook somewhere for how astronomers are supposed to mangle Latin?

  7. Charles

    (I wonder the same thing about all the anglicized Spanish place names in California.)

  8. The large version on Flickr looks amazing on the new iPad, with its high resolution. I can zoom in almost far enough to see some alien ships.

  9. Whoah! That is one stunning galaxy image – love the aerial perspective there – and then the second extra arms surprise shot – wow! 😀

    Marvellous, thankyou BA & Andre vd Hoeven – & Hubble and the others too. :-)

  10. It’s wikipedia page (linked to my above comment ) notes that Messier 106 is a Seyfert galaxy and has a water vapour maser as well as a possible companion galaxy NGC 4217 an edge on spiral with another fainter one visible in the amateur astronomer’s image there. (Also directly linked to my name here – taken by Wilson – can’t find first /last name there.)

    That second smaller and fainter one almost reminds me of the Large Magellanic Cloud in relation to our Galaxy – wonder if there’s any connection with M106’s shape and AGN dynamism? No idea though whether that second smaller companion – NOT NGC 4217 – is physically associated with M106 or just a backdrop line-of-sight galaxy. Anyone here able and willing to shed any light on that or know what that apparent companion’s designation is by any chance, please?

    There are a number of other faint background galaxies in that Wilson picture too – a pair that the smaller galaxy there that the smaller LMC look-alike points too in the top centre of the astrophoto and a small spiral below diagonally left of NGC 4217 and a faint elleptical witha starlike core and faint milky halo below M106 and in line with NGC 4217 plus several others.

    Also, judging from the power in those beams, if they were aimed at us the core of that galaxy would be really bright, and M106 would be a heckuva lot more famous than it already is. I wonder if it would be naked eye visible? It’s possible.

    Messier 106 – seen from 25 million light years distance – currently has an apparent magnitude of 9.1 — so it’d certainly need to increase its apparentluminosity multifold times to reach sixth magnitude. Still I’ve read in one of Tim Ferrises excellent works that a ceryain type of AGN would shine as brightly as our Sun if were located in our Local Group of galaxies so, yeah, maybe -even if it isn’t exactly that sortof AGN! 😉


    “Quasars are so luminous that if one was in action in a local group galaxy its brilliance would rival that of the Sun.”
    – P.284, Ferris, ‘Seeing in the Dark’, Simon & Schuster, 2002.

  11. (Also directly linked to my name here – taken by Wilson – can’t find first /last name there.)

    D’oh! Sometimes the things right in front of your eyes that you miss. Aaaaarrrgh! :-(

    Make that HunterWilson who took the photo. Not sure if that’s one hyphenated surname or a first and last name combo. My apologies to the individual in question and thanks for posting that astrophotograph on wiki for us all. :-)

    Apologies too for the typographical errors that I could swear my computer adds in after I’ve clicked the submit button. Honestly! 😉

  12. Charles- try saying it in Old Entish, but, as per usual, take your time…

  13. eric

    So if solar systems have a goldilocks zone, is there a similar “galactic goldilock zone” where stars a certain distance from the center of a galaxy are more likely to be favorable for solar systems such as our own?

  14. Jon Hanford


    That system you’re looking at near M106 is the small companion galaxy NGC 4248. NED(NASA/IPAC Extragalactic Database) pegs its’ distance at 7.3 Mpc (the distance to M 106 is given as 7.4 Mpc).

    Intriguingly, despite the info noted in the wiki entry(and SIMBAD), NGC 4217 appears NOT to be a companion to M 106. NED gives its’ distance as 19.6 Mpc, over 10 Mpc more distant than M 106. Also, a 2010 study of the satellite galaxies of M 106 found over a dozen companions, including NGC 4248 but, alas, not NGC 4217(an interesting read, btw): http://arxiv.org/pdf/1011.2830v1.pdf

  15. Messier Tidy Upper

    @ ^ Jon Hanford : Cheers for that – much appreciated. :-)

    @13. eric : Yep. I think I’ve heard /read that GHZ idea mentioned a few times. Ideally a star isn’t in the dangerous galactic bulge region too close to an occssionally active and crowded nucleus and not too far away and hence likely to be too “metal” poor to enable life and technology to develop. Mind you its just an educated extrapolation and we’ve gathered far too little data at this stage to tell whether it has much validity or not. :-)

    @12. Jess Tauber : “Charles- try saying it in Old Entish, but, as per usual, take your time…”

    LOL. Have you finished saying it yet then? (I won’t ask you to repeat it! Come to think of it, I shouldn’t interupt you should I?) 😉

  16. Matt B.

    I’ll try to cover the basics, Charles, using the IPA in the pronunciations.

    1) Vowels are pronounced as in English for the most part (hard to tell whether they will be long, though; compare “dāta” and “dăta”), but since “-es” involves a silent e in English, the pronunciation in anglicized Latin is /iz/.

    2) Consonant sounds are “modernized” to match Modern English, meaning c sounds like /s/ before an e, i or y, g sounds like /dʒ/ before the same vowels, j and v are consonants, instead of semivowels. Some palatization occurs, such as in “ratio”, and “fasces”.

    3) Vowel length is ignored, but the placement of stress is retained from Latin, so for instance, “Eridanus” is e-RI-da-nus, not e-ri-DA-nus.

    4) The diphthongs ae and oe are pronounced the same as an e in the same place would be, and even affect c and g in the same way (e.g. “Caesar” and “algae”).


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