scholarly journals Radioactive decay of GRB-SNe at late-times

2017 ◽  
Vol 12 (S331) ◽  
pp. 45-50
Author(s):  
Kuntal Misra ◽  
A. S. Fruchter
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Hubble Space Telescope ◽  
Radioactive Decay ◽  
Decay Rates ◽  
Late Time ◽  
Time Decay ◽  
Remarkable Similarity ◽  
Time Decay Rates ◽  
Color Data

AbstractWe present the late-time Hubble Space Telescope observations of two Gamma Ray Burst (GRB) associated supernovae (SNe), GRB 030329/SN 2003dh and XRF 060218/SN 2006aj. Using the multi-color data up to ~320 days after the burst, we constrain the late-time decay nature of these SNe. The decay rates of SN 2003dh are steeper than SN 2006aj. A comparison with two other GRB SNe, GRB 980425/SN 1998bw and the SN associated with XRF 020903, shows that the decay rates of SN 2003dh are similar to XRF 020903 and those of SN 2006aj are similar to SN 1998bw. The late-time decay rates are steeper than the 56Co→56Fe radioactive decay rate indicating that there is some leakage of gamma-rays. We also compare the late-time decay rates of nine type Ic SNe, including the SNe of long GRBs, Ic broad lined and normal Ics. The decay rates of the SNe sample show a remarkable similarity in I band at late-times with a scatter of ~10%.

STABILITY OF SHOCK PROFILES FOR NONCONVEX SCALAR VISCOUS CONSERVATION LAWS

1995 ◽  
Vol 05 (03) ◽  
pp. 279-296 ◽  
Author(s):  
MING MEI
Keyword(s):  
Conservation Laws ◽  
Decay Rates ◽  
Asymptotically Stable ◽  
Time Decay ◽  
Shock Condition ◽  
Viscous Conservation Laws ◽  
Time Decay Rates ◽  
Shock Profiles ◽  
Degenerate Shock ◽  
The Stability

This paper is to study the stability of shock profiles for nonconvex scalar viscous conservation laws with the nondegenerate and the degenerate shock conditions by means of an elementary energy method. In both cases, the shock profiles are proved to be asymptotically stable for suitably small initial disturbances. Moreover, in the case of nondegenerate shock condition, time decay rates of asymptotics are also obtained.

scholarly journals Low-Γ jets from Compact Binary Mergers as Candidate Electromagnetic Counterparts to Gravitational Wave Sources

2016 ◽  
Vol 12 (S324) ◽  
pp. 66-69
Author(s):  
Gavin P. Lamb ◽  
Shiho Kobayashi
Keyword(s):  
Gravitational Wave ◽  
Gamma Ray ◽  
Ambient Medium ◽  
Radioactive Decay ◽  
Prompt Gamma ◽  
Late Time ◽  
Astrophysical Jets ◽  
Power Law Distribution ◽  
Compact Binary ◽  
Binary Mergers

AbstractCompact binary mergers, with neutron stars or neutron star and black-hole components, are thought to produce various electromagnetic counterparts: short gamma-ray bursts (GRBs) from ultra-relativistic jets followed by broadband afterglow; semi-isotropic kilonova from radioactive decay of r-process elements; and late time radio flares; etc. If the jets from such mergers follow a similar power-law distribution of Lorentz factors as other astrophysical jets then the population of merger jets will be dominated by low-Γ values. The prompt gamma-rays associated with short GRBs would be suppressed for a low-Γ jet and the jet energy will be released as X-ray/optical/radio transients when a shock forms in the ambient medium. Using Monte Carlo simulations, we study the properties of such transients as candidate electromagnetic counterparts to gravitational wave sources detectable by LIGO/Virgo. Approximately 78% of merger-jets result in failed GRB with optical peaks 14-22 magnitude and an all-sky rate of 2-3 per year.

scholarly journals The case for a high-redshift origin of GRB 100205A

2019 ◽  
Vol 488 (1) ◽  
pp. 902-909
Author(s):  
A A Chrimes ◽  
A J Levan ◽  
E R Stanway ◽  
E Berger ◽  
J S Bloom ◽  
...  
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Near Infrared ◽  
Gamma Ray ◽  
Hubble Space Telescope ◽  
High Redshift ◽  
Gamma Ray Bursts ◽  
Host Galaxy ◽  
Late Time ◽  
Time Limits

Abstract The number of long gamma-ray bursts (GRBs) known to have occurred in the distant Universe (z > 5) is small (∼15); however, these events provide a powerful way of probing star formation at the onset of galaxy evolution. In this paper, we present the case for GRB 100205A being a largely overlooked high-redshift event. While initially noted as a high-z candidate, this event and its host galaxy have not been explored in detail. By combining optical and near-infrared Gemini afterglow imaging (at t < 1.3 d since burst) with deep late-time limits on host emission from the Hubble Space Telescope, we show that the most likely scenario is that GRB 100205A arose in the range 4 < z < 8. GRB 100205A is an example of a burst whose afterglow, even at ∼1 h post burst, could only be identified by 8-m class IR observations, and suggests that such observations of all optically dark bursts may be necessary to significantly enhance the number of high-redshift GRBs known.

scholarly journals Time decay rates for the compressible viscoelastic flows

2017 ◽  
Vol 452 (2) ◽  
pp. 990-1004 ◽  
Author(s):  
Guochun Wu ◽  
Zhensheng Gao ◽  
Zhong Tan
Keyword(s):  
Decay Rates ◽  
Viscoelastic Flows ◽  
Time Decay ◽  
Time Decay Rates

scholarly journals 60Fe and Massive Stars

2008 ◽  
Vol 4 (S252) ◽  
pp. 333-338
Author(s):  
Wei Wang
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Massive Stars ◽  
Radioactive Decay ◽  
Line Emission ◽  
Flux Ratio ◽  
Core Collapse ◽  
Analysis Method ◽  
Line Flux ◽  
Average Flux

AbstractGamma-ray line emission from radioactive decay of 60Fe provides constraints on nucleosynthesis in massive stars and supernovae. We detect the γ-ray lines from 60Fe decay at 1173 and 1333 keV using three years of data from the spectrometer SPI on board INTEGRAL. The average flux per line is (4.4 ± 0.9) × 10−5 ph cm−2 s−1 rad−1 for the inner Galaxy region. Deriving the Galactic 26Al gamma-ray line flux with using the same set of observations and analysis method, we determine the flux ratio of 60Fe/26Al gamma-rays as 0.15 ± 0.05. We discuss the implications of these results for the widely-held hypothesis that 60Fe is synthesized in core-collapse supernovae, and also for the closely-related question of the precise origin of 26Al in massive stars.

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