ABSTRACT
We present the most extensive sample of 45 type I (short) and 275 type II (long) gamma-ray bursts (GRBs) with known redshift to investigate the correlation between the rest-frame peak ...energy, Ep,i and the total isotropic equivalent energy, Eiso of the prompt emission (Amati relation). The Ep,i–Eiso correlation for type I bursts is found to be well distinguished from the one constructed for type II bursts and has a similar power-law index value, Ep,i$\propto E_\text{iso}^{~0.4}$, which possibly indicates the same emission mechanism of both GRB types. We show that the initial pulse complex (IPC) of type I bursts with an extended emission and regular type I bursts follow the same correlation. We obtain similar results for type II bursts associated with Ic supernovae and for regular type II bursts. Three possible outliers from the Ep,i–Eiso correlation for type II subsample are detected. Significant evolution of the Ep,i–Eiso correlation with redshift for type II bursts is not found. We suggest the new classification method, based on the Ep,i–Eiso correlation and introduce two parameters, $EH = E_\text{p,i,2} ~ E_\text{iso,51}^{~-0.4}$ and $EHD = E_\text{p,i,2} ~ E_\text{iso,51}^{~-0.4} ~ T_\text{90,i}^{~-0.5}$, where Ep,i,2 is the value of Ep,i parameter in units of 100 keV, Eiso,51 is the value of Eiso parameter in units of 1051 erg, and T90,i is the rest-frame duration in units of seconds. EHD is found to be the most reliable parameter for the blind type I/type II classification, which can be used to classify GRBs with no redshift.
Abstract
Gamma-ray bursts (GRBs) are classified into long and short events. Long GRBs (LGRBs) are associated with the end states of very massive stars, while short GRBs (SGRBs) are linked to the ...merger of compact objects. GRB 200826A was a peculiar event, because by definition it was an SGRB, with a rest-frame duration of ∼0.5 s. However, this event was energetic and soft, which is consistent with LGRBs. The relatively low redshift (
z
= 0.7486) motivated a comprehensive, multiwavelength follow-up campaign to characterize its host, search for a possible associated supernova (SN), and thus understand the origin of this burst. To this aim we obtained a combination of deep near-infrared (NIR) and optical imaging together with spectroscopy. Our analysis reveals an optical and NIR bump in the light curve whose luminosity and evolution are in agreement with several SNe associated to LGRBs. Analysis of the prompt GRB shows that this event follows the
E
p,i
–
E
iso
relation found for LGRBs. The host galaxy is a low-mass star-forming galaxy, typical of LGRBs, but with one of the highest star formation rates, especially with respect to its mass (
log
M
*
/
M
⊙
=
8.6
, SFR ∼ 4.0
M
⊙
yr
−1
). We conclude that GRB 200826A is a typical collapsar event in the low tail of the duration distribution of LGRBs. These findings support theoretical predictions that events produced by collapsars can be as short as 0.5 s in the host frame and further confirm that duration alone is not an efficient discriminator for the progenitor class of a GRB.
ABSTRACT
We present full photometric coverage and spectroscopic data for soft gamma-ray burst GRB 201015A with a redshift z = 0.426. Our data span a time range of 85 d following the detection of GRB. ...These observations revealed an underlying supernova SN 201015A with a maximum at 8.54 ± 1.48 d (rest frame) and an optical peak absolute magnitude $-19.45_{-0.47}^{+0.85}$ mag. The SN stands out clearly, since the contribution of the afterglow at this time is not dominant, which made it possible to determine SN’s parameters. A comparison of these parameters reveals that the SN 201015A is the earliest (the minimum Tmax) known SN associated with GRBs. Spectroscopic observations during the SN decay stage showed broad lines, indicating a large photospheric velocity, and identified this SN as a Type Ic-BL. Thus, the SN 201015A associated with the GRB 201015A becomes the 27th SN/GRB confirmed by both photometric and spectroscopic observations. Using the results of spectral analysis based on the available data of Fermi-GBM experiment, the parameters Ep,i = 20.0 ± 8.5 keV and Eiso = (1.1 ± 0.2) × 1050 erg were obtained. According to the position of the burst on the Ep,i–Eiso correlation, GRB 201015A was classified as a type II (long) GRB, which was also confirmed by the T90,i–EH diagram.
New WOLEDs based on π-extended azatrioxa[8]circulenes Ivaniuk, K. B.; Baryshnikov, G. V.; Stakhira, P. Y. ...
Journal of materials chemistry. C, Materials for optical and electronic devices,
2017, Volume:
5, Issue:
17
Journal Article
Peer reviewed
New stable WOLEDs based on π-extended azatrioxa8circulenes have been fabricated. Combining the own blue emission of the azatrioxa8circulenes with the yellow-green emission of the “ m ...-MTDATA:azatrioxa8circulene” exciplex a broad visible region, from 400 to 700 nm, is covered. The so constructed WOLEDs exhibit a luminance exceeding 23 700 cd m −2 and an external quantum efficiency reaching 3%.
In the current study we demonstrate an application of four previously synthesized 1,7-diphenyl-substituted BODIPY species for inverted photovoltaic cells and for organic light-emitting devices ...(OLEDs). Depending on the type of substituents or annulation of the pyridone rings these dyes exhibit spectral properties in the full visible region up to the near-infrared wavelengths. All the studied compounds show very strong visible absorption that can be ascribed to the low lying LUMO levels making them electronically suitable as acceptors for many donor materials. The best fabricated inverted photovoltaic device based on the BODYPI-core derivatives demonstrates a power conversion efficiency equal to 1.36% which is close to previously published reports for related species. Two kinds of deep red OLEDs (doped and undoped) with narrow electroluminescence spectra (full width at half maximum up to 45 nm) have been fabricated. Maximum brightness of 3900 cd m−2 and an external quantum efficiency by 2.3% were achieved for the best OLED structure.
Display omitted
•Several BODIPY-core derivatives have been used for the fabrication of OLEDs and inverted OPV cells.•The designed OLEDs are characterized by the deep-red emission and narrow spectra.•Inverted OPV cells demonstrates the clear dependence of performance on the energies of HOMO/LUMO levels.•Cyclic voltammetry measurements show the dependence of HOMO/LUMO energies on the chemical structure of BODIPY derivatives.•Quantum-chemical calculations support the electrochemical measurements and electronic spectra.
We present observations of the dark gamma-ray burst GRB 051008 provided by Swift/BAT, Swift/XRT, Konus-WIND, INTEGRAL/SPI-ACS in the high-energy domain and the Shajn, Swift/UVOT, Tautenburg, NOT, ...Gemini and Keck I telescopes in the optical and near-infrared bands. The burst was detected only in gamma- and X-rays and neither a prompt optical nor a radio afterglow was detected down to deep limits. We identified the host galaxy of the burst, which is a typical Lyman-break galaxy (LBG) with R-magnitude of 24.06 ± 0.10 mag. A redshift of the galaxy of
$z = 2.77_{-0.20}^{+0.15}$
is measured photometrically due to the presence of a clear, strong Lyman-break feature. The host galaxy is a small starburst galaxy with moderate intrinsic extinction (A
V
= 0.3) and has a star formation rate of ∼60 M⊙ yr−1 typical for LBGs. It is one of the few cases where a GRB host has been found to be a classical LBG. Using the redshift we estimate the isotropic-equivalent radiated energy of the burst to be E
iso = (1.15 ± 0.20) × 1054 erg. We also provide evidence in favour of the hypothesis that the darkness of GRB 051008 is due to local absorption resulting from a dense circumburst medium.
Here, in this erratum we report changes on the D0 pT spectra and nuclear modification factor (RAA) in Au+Au collisions at √sNN = 200 GeV by fixing the errors in the efficiency and selection criteria ...that affected the Au+Au results. The p+p reference spectrum has changed as well and is updated with new fragmentation parameters
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