1 / 9

Recent GRB Results from Swift

John Cannizzo/UMBC/Goddard LSC Meeting, Hanford, WA August 16, 2005 LIGO-G050431-00-Z. Recent GRB Results from Swift. GRBs Trace Comoving Volume. dV/dz = 4πD 2 (z) dD(z)/dz. 36 pre-Swift: <z>=1.4, σ(z)=1.0 7 Swift + 2 other: <z>=2.3, σ(z)=1.3. GRB Rate:.

dai-chan
Download Presentation

Recent GRB Results from Swift

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. John Cannizzo/UMBC/Goddard LSC Meeting, Hanford, WA August 16, 2005 LIGO-G050431-00-Z Recent GRB Results from Swift

  2. GRBs Trace Comoving Volume dV/dz = 4πD2(z) dD(z)/dz 36 pre-Swift: <z>=1.4, σ(z)=1.0 7 Swift + 2 other: <z>=2.3, σ(z)=1.3

  3. GRB Rate: [1] V(z<10) = 4x103 Gpc3 [2] Luminosity Density (V band) = 2x1017 L° Gpc-3 => about 1010 galaxies [3] Rate(BATSE) ~103 yr-1 So, rate per galaxy is about 1 in 107 yr. Frail et al. (2001)

  4. Long GRBs: Jet from a Collapsar (Weiqun Zhang - Stanford)

  5. Short GRBs: NS-NS Merger (Max Ruffert - University of Edinburgh)

  6. BAT+XRT 2-10 keV Decay; f=f0t-α Barthelmy et al. (2005)

  7. Interpretation: “Curvature Effect” Kumar & Panaitescu (2000):

  8. First Localization of a Short GRB Gehrels et al. (2005) • GRB050509b: 40 ms duration (BAT), soft part of the short/hard population • XRT: 11 photons (10σ sig.) • z=0.225 elliptical galaxy • chance probability ~10-4 • Eiso=1.1x1048 erg (15-150 keV) • ~102 E(2004 Dec 27 SGR flare) • --> supports NS-NS merger

  9. Summary • GRBs trace comoving volume of the Universe, which exhibits a maximum at z~1-2. • In two cases, the prompt emission seen in BAT+XRT forms a continuous decay with t-α, where α~3, consistent with “curvature radiation” effect. • Localization of one short GRB appears to be in a luminous, non-star forming elliptical galaxy, consistent with NS-NS merger theory.

More Related