IceCube spies unexplained pattern of cosmic rays

by Jill Sakai, University of Wisconsin

Though still under construction, the IceCube Neutrino Observatory at the South Pole is already delivering scientific results — including an early finding about a phenomenon the telescope was not even designed to study.

IceCube Cosmic Ray Skymap
This “skymap,” generated in 2009 from data collected by the IceCube Neutrino Observatory, shows the relative intensity of cosmic rays directed toward the Earth’s Southern Hemisphere. Researchers from UW-Madison and elsewhere identified an unusual pattern of cosmic rays, with an excess (warmer colors) detected in one part of the sky and a deficit (cooler colors) in another.

IceCube captures signals of notoriously elusive but scientifically fascinating subatomic particles called neutrinos. The telescope focuses on high-energy neutrinos that travel through the Earth, providing information about faraway cosmic events such as supernovas and black holes in the part of space visible from the Northern Hemisphere.

However, one of the challenges of detecting these relatively rare particles is that the telescope is constantly bombarded by other particles, including many generated by cosmic rays interacting with the Earth’s atmosphere over the southern half of the sky. For most IceCube neutrino physicists these particles are simply background noise, but University of Wisconsin-Madison researchers Rasha Abbasi and Paolo Desiati, with collaborator Juan Carlos Díaz-Vélez, recognized an opportunity in the cosmic ray data.

“IceCube was not built to look at cosmic rays. Cosmic rays are considered background,” Abbasi says. “However, we have billions of events of background downward cosmic rays that ended up being very exciting.”

Abbasi saw an unusual pattern when she looked at a “skymap” of the relative intensity of cosmic rays directed toward the Earth’s Southern Hemisphere, with an excess of cosmic rays detected in one part of the sky and a deficit in another. A similar lopsidedness, called “anisotropy,” has been seen from the Northern Hemisphere by previous experiments, she says, but its source is still a mystery.

“At the beginning, we didn’t know what to expect. To see this anisotropy extending to the Southern Hemisphere sky is an additional piece of the puzzle around this enigmatic effect — whether it’s due to the magnetic field surrounding us or to the effect of a nearby supernova remnant, we don’t know,” Abbasi says.

The new result publishes Aug. 1 in The Astrophysical Journal Letters, published by the American Astronomical Society.

You can read the rest of the article here

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61 thoughts on “IceCube spies unexplained pattern of cosmic rays

  1. Hmmm. The article would be more elucidating if it talked about which parts of the sky corresponded to the influx excess/deficit.

  2. Of course to be noted that they are talking of very large energies, TeV., that show this anisotropy. It would be interesting, with regard to Svensmark’s hypothesis, to see whether cloud cover correlates with this anisotropy.
    These very high energy original cosmics interacting with the atmosphere produce the cosmic ray flux measured by the neutron monitors etc. It should also affect the spectra coming from the spread over the world neutron monitors, showing a geographic anisotropy in the magnitudes.

  3. Oh look – a new word – anisotropy.
    And real science with a statement only a true scientist would make — “we don’t know.” This is what makes learning fun, unlike the dogmatic dictates of climate science.

  4. Anna V says “It would be interesting, with regard to Svensmark’s hypothesis, to see whether cloud cover correlates with this anisotropy. ”
    I think the rotation of the earth once every 24hours will smear out any effect from this cosmic anisotropy

  5. tallbloke says: “But, Leif told us only last week that cosmic rays were isotropic to a very high degree. These scientists must be wrong. :-)”
    Well, we don’t know what the difference was between the high and low levels. They might be very close together, which would make Leif right.

  6. We have known for a long time that the cosmic ray flux is not static. The Be-11 proxy has some very high spikes over the past 100,000 years from the ice core data.

  7. It would be helpful to correlate the uneven cosmic ray distribution with changes in cloud cover but not necessarily definitive because both could be consequences of the same seperate cause.
    For example, more cosmic rays during a period of less active sun could appear to correlate well with solar induced changes in the temperatures of the upper atmosphere but both would be seperate consequences of solar variations with no necessity for cosmic rays to affect tempersatures or vice versa.
    For my part I suspect that solar variability does affect the upward energy fluxes through the various layers of the atmosphere and thereby affects air pressure distribution in the troposphere but I am doubtful that the effect of cosmic ray variability is significant compared to that effect of solar variability.
    Although I support Svensmark’s ideas generally I think they may fall at that hurdle.
    [EDIT: Particularly given that the map given is a skymap, not a ground map. The Earth will rotate under that sky, so the hot spots will merely create latitudinal bands of variation… – Mike]

  8. Leon Brozyna says: ”’And real science with a statement only a true scientist would make — “we don’t know.” This is what makes learning fun, unlike the dogmatic dictates of climate science.”’
    Yes!

  9. This is another dimension to the complexities that govern the health and climate of our third rock from the sun. The installation of these detectors at this time is far from serendipity. Recently released photos of galaxies show huge energies flowing from the galactic equators. Some halos and discharges make the galaxies look small. Our solar system is due in 2012 to transit the galactic equator. This happens ever twenty five thousand years, give or take. These erstwhile scientists are preparing for this event, every fourth crossing triggers an ice age. Our insignificant little solar system is on the outer of our galaxy and not really a part of it, but follows a sine wave pattern around the outer edge, unattached so to speak. The next few years may be quite eventful, in both weather and seismic stability, volcanoes may be a real problem, not just for the alarmists but our continued good fortune and health. I feel the coming transit will be a watershed, a wake up call to reality , the gore effect squared. I am hoping I am wrong, and warming is real.

  10. Think of cosmic rays as moving electrically charged particles, and then work out what to call them. Some of us call such things electricity.

  11. Sounds similar to the axis of evil from the WMAP survey. Generally attributed to the headlong rush of all around these parts towards the Virgo super-cluster.

  12. “Our solar system is due in 2012 to transit the galactic equator. This happens ever twenty five thousand years, give or take. ”
    No, we are currently heading in a Northerly direction (Galactically speaking) of oscillation having passed through the Galactic plane some 3 million years ago. Next transit due 30,002,012AD, give or take.
    John.

  13. It reminds me of the IPCC phrase that “CO2 is a LLGHG and well mixed” [pdf] while NASA more recently discovered that it was “lumpy.” This is why climate science is not settled and don’t believe anyone who tells you otherwise. Too many assumptions are made for my liking.

  14. tallbloke says: July 30, 2010 at 10:51 pm
    But, Leif told us only last week that cosmic rays were isotropic to a very high degree.
    These scientists must be wrong. 🙂

    Indeed. Alternatively it may confirm my hypothesis that the ‘solar output – planetary magnetospheres’ feedback is a function of the heliocentric longitude. In addition would explain such maters as the ’~60 year’ cycles, since the two largest magnetospheres meet at the same heliocentric longitude at approx 60 year intervals.

  15. There’s a tendency to think physics and cosmology are all wrapped up (complete) and there’s nothing left but to fill in some details.
    Hubris.
    “There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy.” Hamlet, Act I Scene V

  16. @wayne Job says:
    July 31, 2010 at 1:38 am
    “Our solar system is due in 2012 to transit the galactic equator.”
    That is just spin from the new-age bishops of the mayan calendar, it is to do with the winter solstice lining up with the galactic equator, it is closest in 2049, and it means nothing! (less than 1 degree to go! hold on tight!! anyone scared of polar reversal can purchase a safe ride in rent-a-Merkaba, $777 in advance)

  17. Well,to me this picture looks like they have finally found scientific evidence for the Big Bang insofar, as the red – hot – area may show the direction to the center of the Universe i.e. the point, where the Big Bang actually happened – while the blue, cold area looks just the other way, i.e. away from the center of the Universe.
    This srongly complies with my own, personal theory of the Universe, which includes plain and logical explanations for Dark Matter as well as for Dark Energy.
    No, it doesn’t violate Einstein’s E=MC2, either – but it nontheless allows travels above the speed of light – essentially, matter travelling above the speed of light is, in fact, the core of my theory.
    But, of course, nobody would listen to me, like always… “SIGH!”

  18. “Well,to me this picture looks like they have finally found scientific evidence for the Big Bang insofar, as the red – hot – area may show the direction to the center of the Universe i.e. the point, where the Big Bang actually happened – while the blue, cold area looks just the other way, i.e. away from the center of the Universe.”
    Singularities don’t have centres. Now everyone and I mean everyone, you too ET, hold up your right index finger and look at the very tip. That is where the big bang occurred.
    John.

  19. asmilwho says:
    July 30, 2010 at 10:46 pm

    Anna V says “It would be interesting, with regard to Svensmark’s hypothesis, to see whether cloud cover correlates with this anisotropy. ”
    I think the rotation of the earth once every 24hours will smear out any effect from this cosmic anisotropy

    My error, you are right, it is a sky map they are showing not an earth map.
    Michael Schaefer says:
    July 31, 2010 at 4:06 am
    Well,to me this picture looks like they have finally found scientific evidence for the Big Bang insofar, as the red – hot – area may show the direction to the center of the Universe i.e. the point, where the Big Bang actually happened – while the blue, cold area looks just the other way, i.e. away from the center of the Universe.

    Not really.
    One of the awe inspiring revelations when studying the expansion of the universe from the big bang point is that the center of the universe is everywhere. In other words, each point in the universe is the center of the universe. The expansion is not happening from a space time center outwards, but is the analogue of the two dimensional surface on an expanding balloon, all points recede from each other.

  20. I work at SNOLAB. As Dr Marek Kos mentioned in a recent BBC article, “[SNOLAB] is at 6,000m water equivalent – a figure that’s used to compare it to other experiments – but it’s about 2km underground in the Canadian Shield.” Hot spots of cosmic rays makes sense to me. There seems to be a bit of a band in the graphic which I would suspect would map out to the milky way. — John M Reynolds

  21. “[…] their newly reported findings rule out some proposed theories about the source of the Northern Hemisphere anisotropy.”http://www.news.wisc.edu/18256
    The map needs coordinates. A polar view would also be helpful – along with at least a brief note about temporal variability (but perhaps they have no info on that yet).

  22. Michael Schaefer says:
    July 31, 2010 at 4:06 am
    …….But, of course, nobody would listen to me, like always… “SIGH!”
    I fully understand how you feel. I am FULLY QUALIFIED to portray a Doctor on television. Even so, “they” have conspired against me to deny me the right to prescribe drugs!
    Sigh!
    Dave Springer says:
    July 31, 2010 at 3:56 am
    “There are more things in heaven and earth, Horatio, Than are dreamt of in
    your philosophy.” Hamlet, Act I Scene V
    Dave, This should be posted on the wall of every lab and office of every so-called “scientist”.
    Steamboat Jack (Jon Jewett’s evil twin)

  23. John McKay says:
    July 31, 2010 at 5:04 am
    “[…]Singularities don’t have centres. […]”
    Tell that to Chandrasekhar.

  24. Instead of calling it a sky map (sky being visible effects of the atmosphere), it would be better to call it a star map, or better, astronomic map.
    > Presumably the skymap is made up of snapshots every 24h.
    That would likely only work if the detector was at the south pole. Neutrino detections are so rare that I’d be amazed if they didn’t run full time, so presumably the map is right ascension vs. declination and synced up with the Earth’s sidereal rotation of 23 hours, 56 minutes, the time for a star to appear in the same location of the “sky”.

  25. One probable correction – the cosmic ray events are likely not neutrinos, but muons created by cosmic rays hitting nuclei of atmospheric gases. Some of the high energy events create muons that can penetrate deep enough underground to interfere with neutrino detectors. They’re likely still counting individual muons, or at least showers from individual cosmic rays.
    See also
    http://www.sciencedaily.com/releases/2009/01/090121091228.htm
    http://www.hep.umn.edu/soudan/brochure.html
    http://iopscience.iop.org/0370-1328/87/1/311

  26. asmilwho writes:
    I think the rotation of the earth once every 24hours will smear out any effect from this cosmic anisotropy
    Maybe,
    but isn’t it possible that the anistrophy could have an effect even so, because it might, for example, hit (shine on) a warm ocean during the day one part of the year but hit that ocean the during the night another part of the year?

  27. John McKay says:
    July 31, 2010 at 3:03 am
    No, we are currently heading in a Northerly direction (Galactically speaking) of oscillation having passed through the Galactic plane some 3 million years ago. Next transit due 30,002,012AD, give or take.

    Yup. The solar system wanders above and below the galactic plane cyclically over a period of time I don’t recall offhand.
    It also doesn’t orbit the center of the galaxy at the same rate as the galactic arms so it traverses them at predictable times too. I believe the crossings are separated by millions of years so we shouldn’t expect any significant change from that measured in timeframes measured in tens or even hundreds of human generations.
    Presumably when the solar system traverses a region where there are more stars per cubic parsec it will experience a commensurate increase in cosmic rays.
    But who knows what invisible clouds or jets of limited width the solar system might move through on shorter timescales.

  28. It sure would be nice to see the northern hemisphere part of this map. Sort of looks like the interference pattern of two or more sources.

  29. Pool says:
    I am not sure how to read the map ,
    Which land mass is mostly above the “cooler area”?
    See the comments above–it is not a map of earth (rotating every 24hrs), but of the sky, so it seems to me it would be more appropriate to ask “which constellations correspond with the cooler and warmer areas?

  30. J says:
    July 31, 2010 at 9:09 am
    .. “which constellations correspond with the cooler and warmer areas?”
    J, yup, that’s the question!
    Leif, are you somewhere around?

  31. Let´s be aware that CR are mainly (90%) composed of PROTONS, and these are not a shower of little pebbles, as the current “flitstones” universe believers may suppose, but HYDROGEN NUCLEII, so having the ability of reacting with ozone and oxygen to form WATER.

  32. The the former “Aquarius Age” ( Aquarius is usually represented by a lady pouring a jug full of water…on our head), about 12,000 years ago. Ask Noah! 🙂

  33. John McKay says:
    July 31, 2010 at 3:03 am
    “…
    Next transit due 30,002,012AD, give or take.

    Okay fine — but what time of day, …and standard time or daylight savings?

  34. According to H.Svensmark GCR always mean clouds increase, and ….as protons react with ozone and oxygen more exogenic water:

  35. pat says:
    July 30, 2010 at 11:33 pm
    Now isn’t this interesting. Hmmm.
    ahhh, the most fundamental phrase of scientific discovery!

  36. antonyindia says:
    July 31, 2010 at 3:14 am

    About other (Artic) ice: these Danish scientists looking for Eemian traces hit bedrock at 2537m last 27 July 2010. They write: “The Eemian is the last interglacial period, when climate was warmer than today, and sea level 5 meters higher, and is our best analogue for future climate. ”

    I wonder if anyone has restored any of the SUVs of model year 2537m.

  37. Lucy Skywalker says:
    July 31, 2010 at 6:31 pm

    Is this new work connected to what is already known about Cosmic Microwave Background anisotropy eg see here and here?

    Well, in the sense that finally unexplained anisotropies could question the big bang theory, yes. As I said, the expansion of the universe according the big bang theory has no direction in 3 dimensions , and assumes the monotonic passage of time.
    All points in the universe are from where the big bang started. Like points on the surface of an expanding balloon, they all recede from each other uniformly.
    The evident anisotropies introduced by the existence of galaxies and galaxy clusters are explained as statistical fluctuations in the original energy soup.
    I see no problem in finding a reason for these high energy events, in the 20TeV, range to be anisotropic, coming from some specific source, galactic or extragalactic. This is in contrast to the microwave background that,because it is so cold, is hypothesized to come from the beginning of the universe, and should be isotropic.

  38. Ric Werme says:
    July 31, 2010 at 6:17 am
    “the cosmic ray events are likely not neutrinos, but muons”
    Beg to differ: Neutrinos have no charge; muons are negatively charged. There is an absolute difference in how they are detected.
    Further, neutrinos do not create atmospheric clouds (because a. they are not charged and b. do not interact with atmospheric molecules) and neutrinos have absolutely nothing to do with cosmic microwave background.
    So this is much ado about nothing.

  39. “A picture is worth a thousand words” and some may generate a million questions. We have only just begun a journey of a billion years. Before we finish, we will answer a trillion questions and still have not even begun to know who we are or where we came from or why.

  40. From the paper
    “It is tempting to try to interpret the cosmic-ray excess as
    an artifact of the heliospheric magnetic field. However, the
    maximum gyroradius of a 10 TeV cosmic-ray proton in a 1 μG
    magnetic field is about 0.01 pc, i.e., much larger than the size of
    the heliosphere. As a consequence, the observed anisotropy is
    more likely to be connected to features of the local interstellar
    magnetic field at distances <1 pc. We are also investigating
    L198 ABBASI ET AL. Vol. 718
    the possibility that the cosmic-ray excess is associated with
    structures in theGalactic magnetic field at larger distance scales,
    or with diffusive particle flows from a nearby Galactic source
    such as Vela."

  41. In order to clarify the issue, the Ice cube was designed to check for neutrinos.
    BUT , and this is what this paper is about, ordinary galactic cosmics, i.e charged particles of various kinds, from protons and antiprotons to ions , to positive and negative muons and electrons.
    They have to be charged in order to create the cosmic ray showers that will be detected as background to the desired neutrino signals ( cerenkov light probably), and because of the design of the experiment they are in the Tera electron volt range, TeV.

  42. Lucy Skywalker says:
    July 31, 2010 at 6:31 pm
    Don´t be surprised if the current “Flintstones Universe” paradigm is wrong: All stars and galaxies are connected to the “grid”, as shown in this beautiful image of Andromeda in the infrared ( a “rosary” of stars connected to a central star):
    http://apod.nasa.gov/apod/ap100219.html

  43. A single source of cosmic rays would pepper one hemisphere of the Earth, like a torch shining on a sphere. With this in mind it looks like a very strong single source to the ‘left’ and a weaker single source from the ‘right’.
    It would be interesting to see the map for the whole Earth to see if the pattern continues!

  44. Enneagram says:
    July 31, 2010 at 2:42 pm
    “According to H.Svensmark GCR always mean clouds increase”
    There are databases of ultra high energy GCR events dating back to the 1940s; no one has found much of a systematic correlation between these events and any form of increased clouds, precipitation, heating or cooling.
    Comic ray energies are measured in some multiple of an electronVolt; lets recall that 1eV=1.6*10^-19 Joule. So a TeV cosmic ray is thus on the order 10^-7 Joule of energy. Detectable? yes. An agent of climate change? Hardly.

  45. Michael Schaefer says:
    July 31, 2010 at 4:06 am
    Well,to me this picture looks like they have finally found scientific evidence for the Big Bang insofar, as the red – hot – area may show the direction to the center of the Universe i.e. the point, where the Big Bang actually happened – while the blue, cold area looks just the other way, i.e. away from the center of the Universe.
    ‘fraid not. if you want to see big bang stuff, go look at WMAP. Note that both are milky way oriented coordinates so that the center of our galaxy is in the middle of the chart.
    As Anna V mentioned already, it’s got to be high energy cosmic rays. That’s because lower energy cosmic rays have bent paths meaning we have no way to determine the direction of their travel.
    As for trying to ‘see’ far with the cosmic rays, the high energy ones that don’t change their direction substantially due to magnetic fields (outside our solar system) also cannot travel that far because of interaction (collisions) with the cosmic microwave background photons. In other words, high energy cosmic rays cannot travel large distances on par with the size of the universe. And, lower energy cosmic rays get twisted around direction wise due to the magnetic fields present in the galaxy and outside the galaxy such that there’s no information left as to where or what direction they come from.

  46. “”” anna v says:
    July 30, 2010 at 10:19 pm
    Of course to be noted that they are talking of very large energies, TeV., that show this anisotropy. It would be interesting, with regard to Svensmark’s hypothesis, to see whether cloud cover correlates with this anisotropy. “””
    Anna, would not one also have to map the Cosmic ray distribution along with the map of moisture distribution in the atmosphere to arrive at a Svensmark type picture of an interraction.
    Having cosmic rays where there is no humidy is not a help. Does that sound reasonable to you ?

  47. George E. Smith says:
    August 2, 2010 at 5:44 pm
    Well, George, If the map given were a map of the earth, as I presumed in my comment, there would be a meaning in it, and yes, humidity would have to play a role. But as is, the map is a sky map, i.e. oriented to constellations ( which is not shown) . I would need to read the paper to comment further instead of guessing.
    It is true that very high energy cosmic rays, as these are, are rare and thus cannot affect the climate. They do point a direction though from which energy is being spewed in galactic cosmic rays, and the neutral components of these could arrive with higher frequency from the directions derived. Gamma rays for example and neutral atoms. Due to the rotation of the earth the correlations would be complicated of course, and a latitudinal model 🙂 would be needed. Since they will be neutral no strong correlation with the sun cycles would be expected.
    I think Svensmark has demostrated some correlation of galactic cosmic rays and albedo, so this, if the numbers worked out, would be one more contribution messing up the albedo picture.

  48. IceCube spies unexplained pattern of cosmic rays
    ..Abbasi saw an unusual pattern when she looked at a “skymap” of the relative intensity of cosmic rays directed toward the Earth’s Southern Hemisphere, with an excess of cosmic rays detected in one part of the sky and a deficit in another. A similar lopsidedness, called “anisotropy,” has been seen from the Northern Hemisphere by previous experiments, she says, but its source is still a mystery.
    .. The pattern of cosmic rays also reveals more detail about the interstellar magnetic fields produced by moving gases of charged particles near Earth, which are difficult to study and poorly understood.
    .. Since nearly all cosmic signals are influenced by the interstellar magnetic fields, a better overall picture of these fields would aid a large range of physics and astronomy studies, she says, adding that their newly reported findings rule out some proposed theories about the source of the Northern Hemisphere anisotropy. http://www.news.wisc.edu/18256
    This all sky map reminds me of the Cassini all sky map of the heliosphere and its anisotropy and related interstellar magnetic field interaction.
    http://www.nasa.gov/images/content/394390main_Mitchell-Cassini-Press-Conf-Pres-short-Rev-B%202.jpg
    http://www.nasa.gov/images/content/394391main_Mitchell-Cassini-Press-Conf-Pres-short-Rev-B%203.jpg

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