cosmic strings - possible detections

• AstroPh:0410073 - Kibble discusses new interest in cosmic strings, and the two following observational hints. The first one seems quite serious, at first glance:
  • AstroPh:0302547 gravitational lens - Sazhin et al
  • AstroPh:0406516 gravitational lens - Sazhin et al
  • AstroPh:0406434 grav lens - Schild et al.

Cosmic String Detection

• In http://de.arxiv.org/abs/astro-ph/0410073 Kibble discusses the http://de.arxiv.org/abs/astro-ph/302547 possible detection of a cosmic string which seems to gravitationally lens a background galaxy (Sazhin et al.) In http://de.arxiv.org/abs/astro-ph/0406516 the extra pairs of lensed galaxies predicted by the hypothesis are discussed.
• Aim: Understand the basics about (1) cosmic strings, (2) gravitational lensing versus cosmic string lensing, and test the hypothesis
  • Calculate the probability of seeing the original pair by chance
  • Check whether the statistics of expected numbers of lensed images are correct
  • Propose an independent test of the hypothesis, e.g. using radio observations and prepare an observing proposal

• AstroPh:0601494 Sazhin et al. The true nature of CSL-1 - two identical galaxies merging - have non-identical tidal tails showing merging

how many cosmic strings could there be?

• AstroPh:0503364 Bounds on Cosmic Strings from WMAP and SDSS
  • http://arxiv.org/abs/hep-th/0303269 - discussion of cosmic string density

szukanie kandydatów cosmic-string-lensed galaxies

• W jakich katalogach?
  • wide-shallow surveys (WikipediaEn:SDSS 10⁸ galaktyki bez redshiftów, 2dF-Galaxy WikipediaEn:2dF_Galaxy_Redshift_Survey 245,000 gal z redshiftami) vs narrow-deep surveys (WikipediaEn:Hubble_Deep_Field i więcej nowy, ...)
  • ESO Deep Public Survey: http://www.eso.org/science/eis/surveys/release_60000024_DPS.html
• Jaki testy będzie używać?
  • pierwsze rough filter, później więćej precyzyjność
  • fotometria:
    • WikipediaEn:Digitized_Sky_Survey UK Schmidt Survey + POSS2 + ...
    • parametry od np http://en.wikipedia.org/wiki/Sextractor http://terapix.iap.fr/rubrique.php?id_rubrique=91/index.html http://www-int.stsci.edu/~holwerda/se.html
    • - maximum magnitude difference - , maximum distance between pair of images, similar light profiles, galaxy type, etc.
  • spektro: z muszą być identicyczne (do jaka precyzji?)
    • obrazy - oglądać więćej precyzyjnie
• NED: http://nedwww.ipac.caltech.edu/
• Strasbourg: Katalog katalogów: http://cdsweb.u-strasbg.fr/cats/Cats.htx
• Virtual Observatory: http://www.euro-vo.org/

WMAP vs cosmic shear in galaxies

• HepPh:0405218 A First Glimpse of String Theory in the Sky? Steen Hannestad (SDU, Nordita), Laura Mersini-Houghton (UNC-Chapel Hill)
  • 1 cosmic string shear from gravitational lensing, e.g. WikipediaEn:Abell_2218 - efekt na mapę galaktyków
  • 1 cosmic string efekt na mapa WMAPa
  • Więc: powinna być korelacji