Science News: Galaxies in resonance strip stars; and an astronomy pre-pub site strips an embargo
What happens when a big journal’s love of embargos runs smack into the love among astrophysicists and physicists generally to pre-publish their papers at the on-line watering holes known collectively as arXiv? What might happen is another chink in the embargo system embraced by several prestigious journals.
Science News‘s Ron Cowen is out this morning with a story based upon a report from a Harvard-Smithsonian team. It addresses how ancient, dwarf galaxies wound up with a whopping large ratio of dark matter to stars. It’s at arXiv’s astro-ph collection, dated July 15. It also, as of this morning, is still embargoed at Nature magazine’s press site for release no earlier than the usual time, 1 pm Wednesday afternoon US time.
The news here is not of the sort that would get the wires and big dailies buzzing in any case, one suspects. It is a somewhat arcane theoretical simulation of the behavior of stars and of dark matter should two dwarf galaxies fall into orbit with one another. The team reports that gravitational resonances between the pair’s orbital period, and the period of internal rotation by the smaller of the two, will strip many of the stars from the latter and spray them into space – many to be captured by the larger dwarf galaxy. The strippee would then be left a dim little thing – of the sort seen often orbiting larger galaxies (such as the Milky Way) with far fewer stars than would ordinarily accompany their invisible cocoons of dark matter. One notes that Cowen did not, and perhaps was unable to, quote directly any of the paper’s authors. But he did talk with a few outside experts who also are among those whose work is cited in the article’s footnotes. It was also all public, seeming to clear him of any accusation he broke the embargo.
The paper is interesting and The Tracker has quesions. Cowen’s sources seem to have a few somewhat similar doubts. If such stripping works only on the smaller members of orbiting dwarf galaxies, and if it depends on certain details of the alignments and directions of their releative spin axes, does it then explain well the observed fraction of such galaxies that have a paucity of stars?
Grist for the Mill: At arXiv: Resonant stripping as the origin of dwarf spheroidal galaxies ;
-CP
