Saturday, November 12, 2005

Cosmic string or dark matter

I just received a mail from Rich Murray who has taken many pictures of the region near CSL-1, the "cosmic string lensing" candidate.

For example, the newest picture #31 at the top includes "RML-1" which stands for "Rich Murray Lens 1", but I remain somewhat unconvinced that this rather amateurish picture proves anything.

The primary recipient of the e-mail was Malcolm Fairbairn who just posted an interesting paper arguing that if the CSL-1 event is caused by lensing, it is likely to be a cosmic string rather than a dark matter filament because in the latter case, the corresponding tidally disrupted dark matter halo would have to be as heavy as the Milky Way - and such a halo seems to be absent in other data.

This was always our primary worry - that CSL-1 could be caused by lensing by something that just acts as a string but can be of a rather conventional origin.


  1. Well, "...I remain somewhat unconvinced that this rather amateurish picture proves anything." is the highest praise that this absolute amateur has so far received since June.

    I was surprised to see the number of visits to the 31 photos on site, AstroDeep , jumping from just over 200 to now 665,
    so I am grateful to know who to credit -- Thanks!

    Only the first 17 photos are from the CSL-1 field, the next two are from the Millenium Simulation, then 20 to 31 are selected and imaged processed from the Hubble Ultra Deep Field. More important than the possibility that the double blue galaxy in #31 is lensed by a cosmic string, are the myriad bright blue 1-2 pixel (0.03 arc-sec) sources, which are always on a faint, but obvious upon scrutiny, fractile 3D dark mesh, that is backlit by a uniform faint maroon glow.

    Just over a hundred views so far of this one -- I welcome all feedback -- no need to be positive or even polite, though humor is always appreciated....

    Rich Murray
    1943 Otowi Road, Santa Fe, New Mexico 87505 505-501-2298
    two classes of readily noticeable common, ubiquitous, uniform bright
    blue sources in deep background (Murray mesh) of HUDF, dwarf galaxy
    luminous bare clumps, hyper novae?: 2005.04.01 BG and DM Elmegreen:
    Malcolm Fairbairn: Murray 2005.11.11

  2. Correct email for Rich Murray is

    Photo #31 is 3.75 arc-seconds wide.

    The 31 photos at have been visited 866 times.

    In mutual service, Rich Murray