Jet Breaks in Short Gamma‐Ray Bursts. I. The Uncollimated Afterglow of GRB 050724

Grupe, D.; Burrows, D. N.; Patel, S.; Kouveliotou, C.; Zhang, Bing; Mészáros, P.; Wijers, R. A. M. J.; Gehrels, N.

doi:10.1086/508739

Cited by 131 publications

(145 citation statements)

References 45 publications

(97 reference statements)

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“…It has been suggested that low-luminosity LGRBs (e.g., GRB 980425, GRB 031203, and GRB 060218) have large, and perhaps nearly quasispherical, opening angles when compared to traditional LGRBs (Soderberg et al 2004b(Soderberg et al , 2006bLiang et al 2007). Similarly, of the three SGRBs with estimated opening angles, GRB 050709 and GRB 050724 have large measured angles, Θ ∼ 14 • ) and ∼25 • (Grupe et al 2006;Malesani et al 2007), respectively, while GRB 051221 has 4 • < Θ < 8 • Soderberg et al 2006a), which is more typical of traditional high E γ, ISO LGRB opening angles. Yet both long and short populations appear to largely fall on a simple log-linear relationship between afterglow intensity and gamma-ray luminosity over 6 orders of magnitude in energy.…”

Section: Summary and Discussionmentioning

confidence: 99%

A Comparison of the Afterglows of Short- And Long-Duration Gamma-Ray Bursts

Nysewander

Fruchter

Pe’er

2009

ApJ

158

204

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We present a comparative study of the observed properties of the optical and X-ray afterglows of short-and long-duration γ -ray bursts (GRBs). Using a large sample of 37 short and 421 long GRBs, we find a strong correlation between the afterglow brightness measured after 11 hr and the observed fluence of the prompt emission. Both the optical (R band) and X-ray flux densities (F R and F X ) scale with the γ -ray fluence, F γ . For bursts with a known redshift, a tight correlation exists between the afterglow flux densities at 11 hr (rest frame) and the total isotropic γ -ray energy, E γ,ISO : F R,X ∝ E γ,ISO α , with α 1. The constant of proportionality is nearly identical for long and short bursts, when E γ,ISO is obtained from the Swift data. Additionally, we find that for short busts with F γ 10 −7 erg cm −2 , optical afterglows are nearly always detected by reasonably deep early observations. Finally, we show that the ratio F R /F X has very similar values for short and long bursts. These results are difficult to explain in the framework of the standard scenario, since they require that either (1) the number density of the surrounding medium of short bursts is typically comparable to, or even larger than the number density of long bursts; (2) short bursts explode into a density profile, n(r) ∝ r −2 ; or (3) the prompt γ -ray fluence depends on the density of the external medium. We therefore find it likely that either basic assumptions on the properties of the circumburst environment of short GRBs or else the standard models of GRB emission must be re-examined. We believe that the most likely solution is that the ambient density surrounding typical short bursts is higher than has generally been expected: a typical value of ∼1 cm −3 is indicated. We discuss recent modifications to the standard binary merger model for short bursts which may be able to explain the implied density.

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Section: Summary and Discussionmentioning

confidence: 99%

A Comparison of the Afterglows of Short- And Long-Duration Gamma-Ray Bursts

Nysewander

Fruchter

Pe’er

2009

ApJ

158

204

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“…One immediate advantage offered by GRBs is that their bright electromagnetic emission allows a precise localization of the source on the sky, pinpointing the source directionn and lifting some of the degeneracies which limit distance determination. The extent of collimation in short GRBs is not well known, although recent analyses suggest that there may be a rather wide range in jet collimation from burst to burst [24,25]. For bursts that arise from binary NS mergers, our theoretical expectation is that emission should be beamed preferentially along the orbital angular momentum axis, where baryon loading is minimized.…”

Section: Grbs Observed By Gw Networkmentioning

confidence: 94%

Short GRB and binary black hole standard sirens as a probe of dark energy

Dalal

Holz

Hughes³

et al. 2006

Phys. Rev. D

311

340

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Observations of the gravitational radiation from well-localized, inspiraling compact-object binaries can measure absolute source distances with high accuracy. When coupled with an independent determination of redshift through an electromagnetic counterpart, these standard sirens can provide an excellent probe of the expansion history of the Universe and the dark energy. Short γ-ray bursts, if produced by merging neutron star binaries, would be standard sirens with known redshifts detectable by ground-based gravitational wave (GW) networks such as Advanced Laser Interferometer Gravitational-wave Observatory (LIGO), Virgo, and Australian International Gravitational Observatory (AIGO). Depending upon the collimation of these GRBs, the measurement of about 10 GW-GRB events (corresponding to about 1 yr of observation with an advanced GW detector network and an all-sky GRB monitor) can measure the Hubble constant h to ~ 2-3%. When combined with measurement of the absolute distance to the last scattering surface of the cosmic microwave background, this determines the dark energy equation of state parameter w to ~9%. Similarly, supermassive binary black hole inspirals will be standard sirens detectable by Laser Interferometer Space Antenna (LISA).Depending upon the precise redshift distribution, ~100 sources could measure w at the ~4% level. Disciplines Physical Sciences and Mathematics | PhysicsComments

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“…Swift and HETE-2 observations have provided evidence of clear similarities with the afterglows detected in the correspondence of long GRBs, because of the detection of X-ray and optical afterglows (Soderberg 2006;Grupe 2006;Berger 2007). Other similarities identified in the spectra for the initial stage of short and long GRBs and the presence, in some cases, of X-ray flares infers that a common mechanism operates during the first few seconds (Barthelmyet et al 2005;Coward, 2007).…”

Section: Introductionmentioning

confidence: 93%

z= 1 multifractality of Swift short GRBs?

Tamburini

2010

A&A

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Aims. We analyze and characterize the angular distribution of selected samples of gamma ray bursts (GRBs) from BATSE and Swift data to confirm that the division into two classes of short-and long-duration GRBs also correspond to two distinct spatial populations. Methods. The angular distribution is analyzed using multifractal analysis and characterized by a multifractal spectrum of dimensions. Different spectra of dimensions relate to different angular distributions.Results. The spectra of dimensions of short and long bursts indicate that the two populations indeed have two different angular distributions. Both Swift and BATSE long bursts appear to be homogeneously distributed across the sky with a monofractal distribution. In contrast, short GRBs follow a multifractal distribution for both the two samples. Even if BATSE data do not enable a unique interpretation of their angular distribution to be made because of the instrumental selection effects that mainly favor the detection of nearby GRBs, the results from Swift short GRBs confirm this behavior, also when including GRBs corrected by the redshift factor. The distributions traced by short GRBs, up to z = 1, depict a universe with a structure similar to that of a disordered porous material with uniformly distributed heterogeneous irregular structures, appearing more clustered than expected.

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Jet Breaks in Short Gamma‐Ray Bursts. I. The Uncollimated Afterglow of GRB 050724

Cited by 131 publications

References 45 publications

A Comparison of the Afterglows of Short- And Long-Duration Gamma-Ray Bursts

A Comparison of the Afterglows of Short- And Long-Duration Gamma-Ray Bursts

Short GRB and binary black hole standard sirens as a probe of dark energy

z= 1 multifractality of Swift short GRBs?

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