Keeping Us In the Dark

Posted on by Chad Orzel

You might think that, being a sciene blogger and all, I would have sources of science news that aren’t available to the average person on the street. You would be right, though they’re not as useful as you might think… The source for today’s news teaser is actually a thank-you email from a prospective student I talked to on Friday.

So, anyway, those little scamps at NASA are playing all coy with some sort of announcement regarding dark matter:

Astronomers who used NASA’s Chandra X-ray Observatory will host a media teleconference at 1 p.m. EDT Monday, Aug. 21, to announce how dark and normal matter have been forced apart in an extraordinarily energetic collision.

What they’re announcing, I don’t know, and my Google fu isn’t good enough to turn up any scientific details. But I thought I should throw that out, for anybody who’s interested. And maybe somebody with more knowledge of the situation can clue me in…

16 thoughts on “Keeping Us In the Dark”

  1. Cool. I dunno what this is going to be, but I’ll have to watch for it. I’m hoping that some sort of preprint will show up on arxiv.org at the same time, but who knows.

    Just from the sentence you’re talking about, I’m guessing that this is going to be a galaxy merger, or even a galaxy cluster merger observation, where various forces that affect baryons but not dark matter— um, who am I kidding? Various forces means E&M. Somehow, processes involving massive star formation or AGN jets or *something* will have moved the baryonic matter to a spot where the dark matter isn’t. The Chandra observations may be of lots of hot gas, tracing the baryonic matter in the cluster, and the DM observations may be from gravitational microlensing, tracing the total mass. But that’s just a complete off-the-top-of-my-head guess, not anything inside or informed.

    -Rob

  2. Isn’t that going to be the teleconference where they open the door to the dark matter dimension and release the thing that cannot be named? Are my dates off on this one?
    – Armand

  4. Ha ha, I know what it is. But I can’t tell you.

    Bastard!
    And here I was hoping that having you on their information panel would lead to some high-quality leaks to the blogosphere…

    Can you give us a hint? Is it bigger than a breadbox?

  5. Yeah, I’m going with commenter #1 to guess that it’s a galaxy merger, and the IGM got halted and heated up pretty good by merger related shocks (hence X-ray observations) while they have some dynamical measurements (satellite galaxies?) showing that the overall potential is much more puffed up — egthe merged dark halo is much more extended.

  6. Yeah, word is that it is collisions and baryons separate hydrodynamically.
    I wouldn’t hold my breath, be neat with some nice pictures, but early word is no big surprises.
    Hope to be proven wrong.

  7. I can reveal that astronomers have used NASA’s Chandra X-ray Observatory to observe that dark and normal matter have been forced apart in an extraordinarily energetic collision. Beyond that, I need to milk the notion that I’m protecting some delicious secret for all it’s worth.

  8. I can reveal that astronomers have used NASA’s Chandra X-ray Observatory to observe that dark and normal matter have been forced apart in an extraordinarily energetic collision. Beyond that, I need to milk the notion that I’m protecting some delicious secret for all it’s worth.

    Jeez, you move to California, and suddenly it’s all secrecy and showmanship…

    I remember when it was all about the science, man…

  11. Odds are that it is followup to Markevitch and Clowe et al ApJ 606 819 (2004)
    http://www.journals.uchicago.edu/ApJ/journal/issues/ApJ/v606n2/58959/58959.html
    or another similar cluster since 1E 0657-56 has already been observed with Chandra.
    My bet is that it is deeper Chandra obs of the same target, with new simulations and they will argue for very low cross-section upper limit on SIDM – definitely in fact, since the press release URL has 1e0657 imaginatively in the path name!

    If they claim a non-zero measurement of SIDM cross-section it is interesting, if it is model dependent new upper limit then “blah”.

    Sean – is it a true SSU – are you guys going to be at HQ in the studio, or is it an all-telecon event. Reason I ask is that far as I can tell HQ stopped doing in-studio SSUs sometime this year; or if they did one the publicity was rather poor ’cause I can’t even find it by actively looking, much less having it thrust in my face which they usually do.

  12. yup, in fact a quick search shows multiple Chandra observations of 1E0657-56 using ACIS-I back in 2004. Go much deeper than original published data, so I’m figuring they finally put all the deep observations together and did some models.
    All the data have been public for over a year btw if anyone wants to grab it and take a look 😉

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