The AstroStat Slog » afterglow http://hea-www.harvard.edu/AstroStat/slog Weaving together Astronomy+Statistics+Computer Science+Engineering+Intrumentation, far beyond the growing borders Fri, 09 Sep 2011 17:05:33 +0000 en-US hourly 1 http://wordpress.org/?v=3.4 [ArXiv] GRB host galaxies, Aug. 10, 2007 http://hea-www.harvard.edu/AstroStat/slog/2007/arxiv-grb-host-galaxies/ http://hea-www.harvard.edu/AstroStat/slog/2007/arxiv-grb-host-galaxies/#comments Tue, 14 Aug 2007 16:47:04 +0000 hlee http://hea-www.harvard.edu/AstroStat/slog/2007/arxiv-grb-host-galaxies-aug-10-2007/ From arxiv/astro-ph:0708.1510v1
Connecting GRBs and galaxies: the probability of chance coincidence by Cobb and Bailyn

Without an optical afterglow, a galaxy within the 2 arc second error region of a GRB x-ray afterglow is identified as a host galaxy; however confusion can rise due to the facts that 1. the edge of a galaxy is diffused, 2. multiple sources could exist within 2 arc second error region, 3.the distance between the galaxy and the x-ray afterglow is measured by projection, and 4. lensing causes increase of brightness and position shifts. In this paper, the authors “investigated the fields of 72 GRBs in order to examine the general issue of associations between GRBs and host galaxies.”

The authors added some statistical issues on this matching GRBs and host galaxies but current knowledge and techniques seem short to tackle the problem. Yet, to prevent false discovery, the authors proposed strategic studies for the followings:

  • Gamma-ray luminosity indicators
  • Detection (or non-detection ) SNe (Supernova) for long-duration bursts
  • Classification of associated galaxy : long-duration and short-duration bursts are associated with late-type and early-type galaxies, respectively
  • Optical afterglow spectral absorption features
  • Visual detection of true host galaxy as happened with GRB 060912a
  • X-ray afterglow spectral emission lines, and
  • Strong lensing of x-ray afterglows

As multi-wavelength studies become popular nowadays, this source matching issue across bands continuously arises where statistics can contribute the validity of source matching methods. So far, those methods are incomprehensible to statisticians.

]]> http://hea-www.harvard.edu/AstroStat/slog/2007/arxiv-grb-host-galaxies/feed/ 0 [ArXiv] Complete Catalog of GRBs from BeppoSAX, July 13, 2007 http://hea-www.harvard.edu/AstroStat/slog/2007/arxiv-complete-catalog-of-grbs-from-bepposax/ http://hea-www.harvard.edu/AstroStat/slog/2007/arxiv-complete-catalog-of-grbs-from-bepposax/#comments Mon, 16 Jul 2007 16:15:52 +0000 hlee http://hea-www.harvard.edu/AstroStat/slog/2007/arxiv-complete-catalog-of-grbs-from-bepposax-july-13-2007/ From arxiv/astro-ph:0707.1900v1
The complete catalogue of gamma-ray bursts observed by the Wide Field Cameras on board BeppoSAX by Vetere, et.al.

This paper intend to publicize the largest data set of Gamma Ray Burst (GRB) X-ray afterglows (right curves after the event), which is available from http://www.asdc.asi.it. It is claimed to be a complete on-line catalog of GRB observed by two wide-Field Cameras on board BeppoSAX (Click for its Wiki) in the period of 1996-2002. It is comprised with 77 bursts and 56 GRBs with Xray light curves, covering the energy range 40-700keV. A brief introduction to the instrument, data reduction, and catalog description is given.

]]> http://hea-www.harvard.edu/AstroStat/slog/2007/arxiv-complete-catalog-of-grbs-from-bepposax/feed/ 1