Absorption Lines Shed New Light on 90 Year Old Puzzle

Article written: 2 Nov , 2011
Updated: 24 Dec , 2015
by

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Using the Gemini North Telescope, astronomers studying the central region of the Milky Way have discovered 13 diffuse interstellar bands with the longest wavelengths to date. The team’s discovery could someday solve a 90-year-old mystery about the existence of these bands.

“These diffuse interstellar bands—or DIBs—have never been seen before,” says Donald Figer, director of the Center for Detectors at Rochester Institute of Technology and one of the authors of a study appearing in the journal Nature.

What phenomenon are responsible for these absorption lines, and what impact do they have on our studies of our galaxy?

Figer offers his explanation of absorption lines, stating, “Spectra of stars have absorption lines because gas and dust along the line of sight to the stars absorb some of the light.”

Figer adds, “The most recent ideas are that diffuse interstellar bands are relatively simple carbon bearing molecules, similar to amino acids. Maybe these are amino acid chains in space, which supports the theory that the seeds of life originated in space and rained down on planets.”

“Observations in different Galactic sight lines indicate that the material responsible for these DIBs ‘survives’ under different physical conditions of temperature and density,” adds team member Paco Najarro (Center of Astrobiology, Madrid).

The discovery of low energy absorption lines by Figer and his team helps to determine the nature of diffuse interstellar bands. Figer believes that any future models that predict which wavelengths the particles absorb will have to include the newly discovered lower energies, stating, “We saw the same absorption lines in the spectra of every star. If we look at the exact wavelength of the features, we can figure out the kind of gas and dust between us and the stars that is absorbing the light.”

Spectra of the newly discovered Diffuse Interstellar Bands (DIB's).
Image Credit: Geballe, Najarro, Figer, Schlegelmilch, and de la Fuente.

Since their discovery 90 years ago, diffuse interstellar bands have been a mystery. To date, the known bands that have been identified before the team’s study occur mostly in visible wavelengths. Part of the puzzle is that the observed lines don’t match the predicted lines of simple molecules and can’t be traced to a single source.

“None of the diffuse interstellar bands has been convincingly identified with a specific element or molecule, and indeed their identification, individually and collectively, is one of the greatest challenges in astronomical spectroscopy, recent studies have suggested that DIB carriers are large carbon-containing molecules.” states lead author Thomas Geballe (Gemini Observatory).

One other benefit the newly discovered infrared bands offer is that they can be used to better understand the diffuse interstellar medium, where thick dust and gas normally block observations in visible light. By studying the stronger emissions, scientists may gain a better understanding of their molecular origin. So far, no research teams have been able to re-create the interstellar bands in a laboratory setting, mostly due to the difficulty of reproducing temperatures and pressure conditions the gas would experience in space.

If you’d like to learn more about the Gemini Observatory, visit: http://www.gemini.edu/
Read more about RIT’s Center for Detectors at: http://ridl.cis.rit.edu/

Source: Rochester Institute of Technology Press Release

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22 Responses

  1. Member
    IVAN3MAN_AT_LARGE says

    Yo Ray, at the paragraph below the spectra graphs, there’s a rogue comma between “years” and “ago” in the first line.

  2. Anonymous says

    How do I get rid of this epic annoying “Recommended for you” popup at the right bottom part of the page?

    • Torbjörn Larsson says

      I didn’t know of them – I use NoScript. (It’s a resource hog, as all Javascript based systems. But it works most of the time.)

      • Anonymous says

        It started today when you scroll down the article and gets in the comments section. It is so annoying that I don’t want to read articles here any-more here on UT. It is recommending other UT articles in a very aggressive way.

    • Anonymous says

      Click on the question mark (upper right corner) and select the -other- option. 😉

      • Anonymous says

        It does not work. (I am using Fire Fox latest version)

        First it is not intuitive to press the question mark. I would expect that when you press the cross that it would be gone forever.

        Second it is way too big and blocks the comment you are reading. If it were just a part at the right side away from any text or comments as a none pop-up that it would not be so annoying.

        It is useless since it promotes other links on this site that I just read or are about to read.

        And when I press to opt out, it is still there only smaller. But when I go to another post it is back again yelling with SPAM.

        Maybe other people love it, but for me it is not working.

        It might work for me if it only asked me once and when I say no, that it never ever shows up again ever. Not even as some small border.

        I am sorry, I don’t want to be negative on this lovely site, but this thing is too aggressive for me.

      • Anonymous says

        Actually, I just realized a few minutes ago that the setting did not remove it for me. 🙁 It did remember that I want to opt-out, but does not appear to be using that answer. I’m also using Firefox. Anybody with other browsers getting a different result?

      • Anonymous says

        Actually, I just realized a few minutes ago that the setting did not remove it for me. 🙁 It did remember that I want to opt-out, but does not appear to be using that answer. I’m also using Firefox. Anybody with other browsers getting a different result?

      • Anonymous says

        Actually, I just realized a few minutes ago that the setting did not remove it for me. 🙁 It did remember that I want to opt-out, but does not appear to be using that answer. I’m also using Firefox. Anybody with other browsers getting a different result?

      • Anonymous says

        It does not work. (I am using Fire Fox latest version)

        First it is not intuitive to press the question mark. I would expect that when you press the cross that it would be gone forever.

        Second it is way too big and blocks the comment you are reading. If it were just a part at the right side away from any text or comments as a none pop-up that it would not be so annoying.

        It is useless since it promotes other links on this site that I just read or are about to read.

        And when I press to opt out, it is still there only smaller. But when I go to another post it is back again yelling with SPAM.

        Maybe other people love it, but for me it is not working.

        It might work for me if it only asked me once and when I say no, that it never ever shows up again ever. Not even as some small border.

        I am sorry, I don’t want to be negative on this lovely site, but this thing is too aggressive for me.

      • Anonymous says

        It does not work. (I am using Fire Fox latest version)

        First it is not intuitive to press the question mark. I would expect that when you press the cross that it would be gone forever.

        Second it is way too big and blocks the comment you are reading. If it were just a part at the right side away from any text or comments as a none pop-up that it would not be so annoying.

        It is useless since it promotes other links on this site that I just read or are about to read.

        And when I press to opt out, it is still there only smaller. But when I go to another post it is back again yelling with SPAM.

        Maybe other people love it, but for me it is not working.

        It might work for me if it only asked me once and when I say no, that it never ever shows up again ever. Not even as some small border.

        I am sorry, I don’t want to be negative on this lovely site, but this thing is too aggressive for me.

    • Member
      Anonymous says

      As krenshala said, click on the questions mark and it gives you the option to opt out. We’re just trying this and seeing how it works. Your annoyance is noted!

      • Anonymous says

        There seems to be bug in it.
        Open a topic, scroll down with the mouse wheel, scroll up and scroll down again. And there is it again bugging you. Also when I change an article it is back big.

      • Anonymous says

        There seems to be bug in it.
        Open a topic, scroll down with the mouse wheel, scroll up and scroll down again. And there is it again bugging you. Also when I change an article it is back big.

      • Anonymous says

        There seems to be bug in it.
        Open a topic, scroll down with the mouse wheel, scroll up and scroll down again. And there is it again bugging you. Also when I change an article it is back big.

  3. Anonymous says

    Para three: ‘Phenomenon is’ or ‘phenomena are’. Ivan, you’re slipping.

  4. ITSRUF says

    The annoying popup does not show up in IE6. It does intrude upon me when using chrome — and the opt out does not make it go away.

  5. ITSRUF says

    The annoying popup does not show up in IE6. It does intrude upon me when using chrome — and the opt out does not make it go away.

  6. ITSRUF says

    The annoying popup does not show up in IE6. It does intrude upon me when using chrome — and the opt out does not make it go away.

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