Gamma‐Ray Burst Dust Echoes Revisited: Expectations at Early Times
نویسندگان
چکیده
منابع مشابه
Gamma-Ray Burst Dust Echoes Revisited: Expectations at Early Times
Gamma-ray burst (GRB) dust echoes were first proposed as an alternative explanation for the supernova-like (SN-like) components to the afterglows of GRB 980326 and GRB 970228. However, the spectroscopic identification of Type Ic SN 2003dh associated with GRB 030329, as well as the identification of SN-like components to the afterglows of other GRBs, appears to have confirmed the GRB/SN paradigm...
متن کاملImaging observations of SN1987A at gammaray energies
The Caltech imaging q-ray telescope was launched by balloon from Alice Springs, NT, Australia for observations of SN1987A during the period 18.80-18.87 November 1987 UT. The preliminary results presented here are derived from 8200 seconds of instrument livetime on the supernova and 2500 seconds on the Crab Nebula and pulsar at a float altitude of 37 kin. We have obtained the first images of the...
متن کاملDust Echoes from Gamma-Ray Bursts.
The deviation from the power-law decline of the optical flux observed in GRB 970228 and GRB 980326 has been used recently to argue in favor of the connection between gamma-ray bursts and supernovae. We consider an alternative explanation for this phenomenon, based on the scattering of a prompt optical burst by 0.1 M middle dot in circle dust located beyond its sublimation radius 0.1-1 pc from t...
متن کاملHard Times or Great Expectations
This paper uncovers an increasing proportion of quoted UK companies omitting cash dividends. Using a large panel of quoted UK companies, we estimate models for the incidence of dividend omissions and cuts as functions of financial characteristics including cash flow, leverage, investment opportunities, investment and company size. These variables account for most of the increase in omission sin...
متن کاملListeners' expectations about echoes can raise or lower echo threshold.
Echo threshold increases with exposure to redundant trains of stimuli. Three experiments were conducted to test the hypothesis that a change in the ongoing train would affect listeners' perception of the echo, but only if it signified an unusual change in room acoustics. The stimulus train was composed of 4-ms narrow-band noise bursts, with the leading sound from a loudspeaker placed 45 degrees...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2005
ISSN: 0004-637X,1538-4357
DOI: 10.1086/432634