More on Science in the age of Ukraine

 I wanted to give you an update on how international science (CERN, in particular) has been reacting to the continued Russian invasion of Ukraine.  The invasion is now in its 8th month, and the four large LHC experiments still have not decided how to publish papers with author lists, affiliations and acknowledgements of funding agencies that reflect that fact.  Papers from the LHC experiments are being sent to the Cornell arXiv with the authors listed as "The ALICE Collaboration," without lists of individual authors, institutional affiliations, or acknowledgements to the funding agencies. 

The papers are also being submitted to diverse scientific journals for review, with the understanding that versions with author lists, affiliations and acknowledgements will be forthcoming, hopefully allowing for timely publication.  Unfortunately, after 8 months, it is clear that the 'timely' part of this is not happening, and it is likely that some journals are becoming less happy about the situation.   They do best on a steady diet of publications.  It will not be easy for them to deal with a brief flood of manuscripts that are ready for publication once the author lists, etc. arrive.  

This will also not make things easier for some of our younger colleages who may be in the job market.  Everybody involved in CERN is well aware of the situation.  However, although the collaborations are making every effort to document their contributions, not having actual published papers may not make things easier farther afield, either in smaller institutions where one interviews with people in other subfields of physics, or in industry.

CERN, for its part, has not taken further visible action, with the last pronouncement being their March 8th announcement. 

A new source of astrophysical neutrinos

 

A likely new source of astrophysical neutrinos has been identified!  In a paper published in Science, the IceCube Collaboration reported on the observation of neutrinos coming from an object called NGC1068, with 4.1 sigma significance.  The probability that this is a random statistical fluctuation is about 1.1 in 100,000.  This calculated significance accounts for the fact that this was part of a search for neutrinos from 110 likely sources that were studied - this is known as correcting for trial factors - essentially the number of experiments that were tried at once.  A version of the paper is also available here, on the Cornell arXiv preprint server).

NGC1068 (also sometimes known as M77) is an Active Galactic Nucleus (AGN) about 47 million light years from Earth.  AGNs are spiral galaxies with supermassive black holes at their center.  These black holes accrete (pull in) matter from the surrounding galaxy; in the process, some of the matter is ejected at relativistic velocities (speeds a fair fraction of the speed of light) in a collimated jet that follows the axis of rotation of the galaxy.  NGC1068 is one of the closer AGNs, so it is not too surprising that it should be one of the first (after TXS0605+56) high-energy astrophysical neutrino sources to be observed.  The signal was composed of about 80 neutrinos over the background, which was mostly  atmospheric neutrinos. The figure above shows the position of the hotspot (including contours corresponding to 68% and 90% positional uncertainty) compared with that of NGC1068, denoted by the red star.   The agreement is good, and there are no other likely sources within the error contours.

NGC1068 was first seen in an earlier IceCube paper, published in 2020 in Physical Review Letters  (also freely available here, from the Cornell arXiv).   That paper used 10 years of data, and observed NGC1068 with a significance of 2.9 sigma.  The higher significance came from a couple of factors: more new data (and some old partial-detector data was dropped), improved calibrations, and an improved analysis method.  Going from 2.9 sigma to  4.1 sigma is a pretty significant improvement for a re-analysis like this; it seems that the largest single factor was the improved calibrations.

Assuming that this holds up (it is not over the 5 sigma threshold ), this will be the second neutrino source seen by IceCube.  Both are AGNs, so those of us who are impatient can see a pattern developing.  That said, there are differences.  TXS0506 is much further away  - 5.6 billion light years.   It is a known source of gamma-rays, while NGC1068 is not - it's jet is surrounded by a dust cloud that would obscure X-rays and gamma-rays.  And, neutrino emission from TXS0506 was associated with a period exhibiting an increase in gamma-rays, while the NGC1068 source is steady state (at least we have not seen evidence for variability).