TY - JOUR
T1 - The luminosity function and the rate of Swift's gamma-ray bursts
AU - Wanderman, David
AU - Piran, Tsvi
PY - 2010/8
Y1 - 2010/8
N2 - We invert directly the redshift-luminosity distribution of observed long Swift gamma-ray bursts (GRBs) to obtain their rate and luminosity function. Our best-fitting rate is described by a broken power law that rises like for 0 < z < 3 and decreases like for z > 3. The local rate is ρ0 ≃ 1.3+0.6-0.7 (Gpc-3 yr-1). The luminosity function is well described by a broken power law with a break at L* ≃ 1052.5±0.2 (erg s-1) and with indices α = 0.2+0.2-0.1 and β = 1.4+0.3-0.6. The recently detected GRB 090423, with z ≈ 8, fits nicely into the model's prediction, verifying that we are allowed to extend our results to high redshifts. While the GRB rate may follow the star formation rate (SFR) for z < 3, the high-redshift slope is shallower than the steep decline in the SFR for 4 < z. However, we cannot rule out a GRB rate that follows one of the recent SFR models.
AB - We invert directly the redshift-luminosity distribution of observed long Swift gamma-ray bursts (GRBs) to obtain their rate and luminosity function. Our best-fitting rate is described by a broken power law that rises like for 0 < z < 3 and decreases like for z > 3. The local rate is ρ0 ≃ 1.3+0.6-0.7 (Gpc-3 yr-1). The luminosity function is well described by a broken power law with a break at L* ≃ 1052.5±0.2 (erg s-1) and with indices α = 0.2+0.2-0.1 and β = 1.4+0.3-0.6. The recently detected GRB 090423, with z ≈ 8, fits nicely into the model's prediction, verifying that we are allowed to extend our results to high redshifts. While the GRB rate may follow the star formation rate (SFR) for z < 3, the high-redshift slope is shallower than the steep decline in the SFR for 4 < z. However, we cannot rule out a GRB rate that follows one of the recent SFR models.
KW - Gamma-ray burst: general
KW - Stars: formation
UR - http://www.scopus.com/inward/record.url?scp=77955261649&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2966.2010.16787.x
DO - 10.1111/j.1365-2966.2010.16787.x
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AN - SCOPUS:77955261649
SN - 0035-8711
VL - 406
SP - 1944
EP - 1958
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -