131 research outputs found
Konus-Wind and Helicon-Coronas-F Observations of Solar Flares
Results of solar flare observations obtained in the Konus-Wind experiment
from November, 1994 to December, 2013 and in the Helicon Coronas-F experiment
during its operation from 2001 to 2005, are presented. For the periods
indicated Konus-Wind detected in the trigger mode 834 solar flares, and
Helicon-Coronas-F detected more than 300 solar flares.
A description of the instruments and data processing techniques are given. As
an example, the analysis of the spectral evolution of the flares
SOL2012-11-08T02:19 (M 1.7) and SOL2002-03-10T01:34 (C5.1) is made with the
Konus-Wind data and the flare SOL2003-10-26T06:11 (X1.2) is analyzed in the
2.223 MeV deuterium line with the Helicon-Coronas-F data.Comment: Published version. A list of the Konus-Wind solar flare triggers and
figures of their time profiles are available at
http://www.ioffe.ru/LEA/Solar
The second Konus-Wind catalog of short gamma-ray bursts
In this catalog, we present the results of a systematic study of 295 short
gamma-ray bursts (GRBs) detected by Konus-Wind (KW) from 1994 to 2010. From the
temporal and spectral analyses of the sample, we provide the burst durations,
the spectral lags, the results of spectral fits with three model functions, the
total energy fluences and the peak energy fluxes of the bursts. We discuss
evidence found for an additional power-law spectral component and the presence
of extended emission in a fraction of the KW short GRBs. Finally, we consider
the results obtained in the context of the Type I (merger-origin) / Type II
(collapsar-origin) classifications.Comment: Accepted to the Astrophysical Journal Supplement Series (7 Figures, 8
Tables
First intermediate flare from SGR 1935+2154
The first intermediate flare from newly discovered SGR 1935+2154 was detected and localized by four Interplanetary network (IPN) spacecraft on 2015 April 12. Among the observing instruments, only Konus- Wind gamma-ray burst spectrometer (KW) was able to measure high-resolution light curves and multi-channel energy spectra of the flare. We report on the results of temporal and spectral analyses of the KW data, the flare energetics, a search for Quasi-Periodic Oscillations in the light curve, and, finally, discuss the source distance estimate based on the distribution of double blackbody spectral fit parameter
KW-Sun: The Konus-Wind Solar Flare Database in Hard X-ray and Soft Gamma-ray Ranges
We present a database of solar flares registered by the Konus-Wind instrument
during more than 27 years of operation, from 1994 November to now (2022 June).
The constantly updated database (hereafter KW-Sun) contains over 1000 events
detected in the instrument's triggered mode and is accessible online at
http://www.ioffe.ru/LEA/kwsun/. For each flare, the database provides
time-resolved energy spectra in energy range from ~20 keV to ~15 MeV in FITS
format along with count rate light curves in three wide energy bands G1 (~20-80
keV), G2 (~80-300 keV), and G3 (~300-1200 keV) with high time resolution (down
to 16 ms) in ASCII and IDL SAV formats. This article focuses on the instrument
capabilities in the context of solar observations, the structure of the KW-Sun
data and their intended usage. The presented homogeneous data set obtained in
the broad energy range with high temporal resolution during more than two full
solar cycles is beneficial for both statistical and case studies as well as a
source of context data for solar flare research.Comment: 10 pages, 6 figures, 1 table. Accepted for publication in ApJ
GROND coverage of the main peak of Gamma-Ray Burst 130925A
Prompt or early optical emission in gamma-ray bursts is notoriously difficult
to measure, and observations of the dozen cases show a large variety of
properties. Yet, such early emission promises to help us achieve a better
understanding of the GRB emission process(es).
We performed dedicated observations of the ultra-long duration (T90 about
7000 s) GRB 130925A in the optical/near-infrared with the 7-channel "Gamma-Ray
Burst Optical and Near-infrared Detector" (GROND) at the 2.2m MPG/ESO
telescope. We detect an optical/NIR flare with an amplitude of nearly 2 mag
which is delayed with respect to the keV--MeV prompt emission by about 300--400
s. The decay time of this flare is shorter than the duration of the flare (500
s) or its delay.
While we cannot offer a straightforward explanation, we discuss the
implications of the flare properties and suggest ways toward understanding it.Comment: 9 pages, 9 figures, accepted for publ. in A&
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