-
V. D. Pal'shin,
K. Hurley,
D. S. Svinkin,
R. L. Aptekar,
S. V. Golenetskii,
D. D. Frederiks,
E. P. Mazets,
P. P. Oleynik,
M. V. Ulanov,
T. Cline, [......],
M. Rapisarda,
P. Soffitta,
G. Di Cocco,
F. Fuschino,
M. Galli,
C. Labanti,
M. Marisaldi,
J. -L. Atteia,
R. Vanderspek,
G. Ricker
[show abstract]
[hide abstract]
ABSTRACT: Between the launch of the GGS Wind spacecraft in 1994 November and the end of
2010, the Konus-Wind experiment detected 314 short-duration gamma-ray bursts
(including 24 bursts which can be classified as short bursts with extended
emission). During this period, the IPN consisted of up to eleven spacecraft,
and using triangulation, the localizations of 276 bursts were obtained. We
present the IPN localization data on these events.
01/2013;
-
E. P. Kontar,
J. C. Brown,
A. G. Emslie, W. Hajdas,
G. D. Holman,
G. J. Hurford,
J. Kašparová,
P. C. V. Mallik,
A. M. Massone,
M. L. McConnell,
M. Piana,
M. Prato,
E. J. Schmahl,
E. Suarez-Garcia
[show abstract]
[hide abstract]
ABSTRACT: X-radiation from energetic electrons is the prime diagnostic of flare-accelerated electrons. The observed X-ray flux (and
polarization state) is fundamentally a convolution of the cross-section for the hard X-ray emission process(es) in question
with the electron distribution function, which is in turn a function of energy, direction, spatial location and time. To address
the problems of particle propagation and acceleration one needs to infer as much information as possible on this electron
distribution function, through a deconvolution of this fundamental relationship. This review presents recent progress toward
this goal using spectroscopic, imaging and polarization measurements, primarily from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). Previous conclusions regarding the energy, angular (pitch angle) and spatial distributions of energetic electrons in solar
flares are critically reviewed. We discuss the role and the observational evidence of several radiation processes: free-free
electron-ion, free-free electron-electron, free-bound electron-ion, photoelectric absorption and Compton backscatter (albedo),
using both spectroscopic and imaging techniques. This unprecedented quality of data allows for the first time inference of
the angular distributions of the X-ray-emitting electrons and improved model-independent inference of electron energy spectra
and emission measures of thermal plasma. Moreover, imaging spectroscopy has revealed hitherto unknown details of solar flare
morphology and detailed spectroscopy of coronal, footpoint and extended sources in flaring regions. Additional attempts to
measure hard X-ray polarization were not sufficient to put constraints on the degree of anisotropy of electrons, but point
to the importance of obtaining good quality polarization data in the future.
KeywordsSun: flares–Sun: X-rays–Sun: acceleration–Sun: energetic particles
Space Science Reviews 04/2012; 159(1):301-355. · 3.61 Impact Factor
-
K Hurley,
I ~G Mitrofanov,
D Golovin,
M ~L Litvak,
A ~B Sanin,
W Boynton,
C Fellows,
K Harshman,
R Starr,
S Golenetskii, [......],
E Mazets,
V Pal'shin,
D Frederiks,
D Svinkin,
D ~M Smith, W Hajdas,
A Kienlin,
X Zhang,
A Rau,
K Yamaoka
Gamma-Ray Bursts 2012 Conference (GRB 2012); 01/2012
-
K Hurley,
J Goldsten,
I ~G Mitrofanov,
D Golovin,
M ~L Litvak,
A ~B Sanin,
S Golenetskii,
R Aptekar,
E Mazets,
V Pal'Shin, [......],
Y Hanabata,
Y Fukazawa,
T Takahashi,
M Tashiro,
Y Terada,
T Murakami,
K Makishima,
D ~M Smith,
J McTiernan, W Hajdas
GRB Coordinates Network. 01/2012; 12993:1.
-
K. Hurley,
J.-L. Atteia,
C. Barraud,
A. Pélangeon,
M. Boër,
R. Vanderspek,
G. Ricker,
E. Mazets,
S. Golenetskii,
D. D. Frederiks, [......],
K. Makishima,
C. Guidorzi,
F. Frontera,
C. E. Montanari,
F. Rossi,
J. Trombka,
T. McClanahan,
R. Starr,
J. Goldsten,
and R. Gold
[show abstract]
[hide abstract]
ABSTRACT: Between 2000 November and 2006 May, one or more spacecraft of the interplanetary network (IPN) detected 226 cosmic gamma-ray bursts that were also detected by the French Gamma-Ray Telescope experiment on board the High Energy Transient Experiment 2 spacecraft. During this period, the IPN consisted of up to nine spacecraft, and using triangulation, the localizations of 157 bursts were obtained. We present the IPN localization data on these events.
The Astrophysical Journal Supplement Series 12/2011; 197(2):34. · 13.46 Impact Factor
-
K. Hurley,
M. Briggs,
V. Connaughton,
C. Meegan,
A. von Kienlin,
A. Rau,
X Zhang,
S. Golenetskii,
R. Aptekar,
E. Mazets, [......],
T Takahashi,
M Tashiro,
Y Terada,
T Murakami,
K. Makishima,
D. M. Palmer,
J. Goldsten,
E. Del Monte,
M. Feroci,
M. Marisaldi
[show abstract]
[hide abstract]
ABSTRACT: In the first two years of operation of the Fermi GBM, the 9-spacecraft
Interplanetary Network (IPN) detected 158 GBM bursts with one or two distant
spacecraft, and triangulated them to annuli or error boxes. Combining the IPN
and GBM localizations leads to error boxes which are up to 4 orders of
magnitude smaller than those of the GBM alone. These localizations comprise the
IPN supplement to the GBM catalog, and they support a wide range of scientific
investigations.
10/2011;
-
E. P. Kontar,
J. C. Brown,
A. G. Emslie, W. Hajdas,
G. D. Holman,
G. J. Hurford,
J. Kasparova,
P. C. V. Mallik,
A.M. Massone,
M.L. McConnell,
M. Piana,
M. Prato,
E. J. Schmahl,
E. Suarez-Garcia
[show abstract]
[hide abstract]
ABSTRACT: X-radiation from energetic electrons is the prime diagnostic of
flare-accelerated electrons. The observed X-ray flux (and polarization state)
is fundamentally a convolution of the cross-section for the hard X-ray emission
process(es) in question with the electron distribution function, which is in
turn a function of energy, direction, spatial location and time. To address the
problems of particle propagation and acceleration one needs to infer as much
information as possible on this electron distribution function, through a
deconvolution of this fundamental relationship. This review presents recent
progress toward this goal using spectroscopic, imaging and polarization
measurements, primarily from the Reuven Ramaty High Energy Solar Spectroscopic
Imager (RHESSI). Previous conclusions regarding the energy, angular (pitch
angle) and spatial distributions of energetic electrons in solar flares are
critically reviewed. We discuss the role and the observational evidence of
several radiation processes: free-free electron-ion, free-free
electron-electron, free-bound electron-ion bremsstrahlung, photoelectric
absorption and Compton back-scatter (albedo), using both spectroscopic and
imaging techniques. This unprecedented quality of data allows for the first
time inference of the angular distributions of the X-ray-emitting electrons
using albedo, improved model-independent inference of electron energy spectra
and emission measures of thermal plasma. Moreover, imaging spectroscopy has
revealed hitherto unknown details of solar flare morphology and detailed
spectroscopy of coronal, footpoint and extended sources in flaring regions.
Additional attempts to measure hard X-ray polarization were not sufficient to
put constraints on the degree of anisotropy of electrons, but point to the
importance of obtaining good quality polarization data.
10/2011;
-
S. Orsi,
D. Haas, W. Hajdas,
V. Honkimäki,
G. Lamanna,
C. Lechanoine-Leluc,
R. Marcinkowski,
M. Pohl,
N. Produit,
D. Rapin,
E. Suarez-Garcia,
D. Rybka,
J.-P. Vialle
[show abstract]
[hide abstract]
ABSTRACT: POLAR is a novel compact space-borne Compton polarimeter conceived for a
precise measurement of hard X-ray polarization and optimized for the
detection of Gamma-Ray Burst (GRB) photons in the energy range
50-500 keV. In December 2009 we have performed a systematic
calibration of one modular unit of POLAR at four energy levels (200,
288, 356 and 511 keV) with a 100% polarized synchrotron radiation source
at the beam line ID15A at ESRF. The detector was displaced several times
on the beam line in order to achieve a uniform illumination, which
mimics the flux from a GRB placed on the zenith of the experiment.
Several rotations of the detector on the beam axis allowed us to test
the response of POLAR to several polarization angles. Two different
analysis methods to reconstruct the polarization angle of the beam and
the modulation factor μ100 are presented; the first relies
on the existence of a unpolarized sample, produced by merging two data
sets with orthogonal polarization directions, and is less dependent on
systematic effects due to asymmetries in the detector; the second is
independent from unpolarized measurements, and will likely be used to
analyze the polarization of GRB during the flight. Both methods
reconstruct the input polarization angle within 2° and produce
modulation factors μ100 between 30% and 50% depending on
the beam energy. Monte Carlo simulations performed with GEANT4 confirm
the experimental results.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 07/2011; 648:139-154. · 1.21 Impact Factor
-
K Hurley,
J Goldsten,
I ~G Mitrofanov,
D Golovin,
M ~L Litvak,
A ~B Sanin,
S Golenetskii,
R Aptekar,
E Mazets,
V Pal'Shin, [......],
D ~M Smith,
R ~P Lin,
J McTiernan,
R Schwartz, W Hajdas,
W Boynton,
C Fellows,
K Harshman,
H Enos,
R Starr
GRB Coordinates Network. 01/2011; 12452:1.
-
K Hurley,
I ~G Mitrofanov,
D Golovin,
M ~L Litvak,
A ~B Sanin,
W Boynton,
C Fellows,
K Harshman,
H Enos,
R Starr, [......],
M Tashiro,
Y Terada,
T Murakami,
K Makishima,
S Barthelmy,
J Cummings,
N Gehrels,
H Krimm,
D Palmer,
J Goldsten
GRB Coordinates Network. 01/2011; 11900:1.
-
S Golenetskii,
R Aptekar,
E Mazets,
V Pal'Shin,
D Frederiks,
D Svinkin,
T Cline,
K Hurley,
I ~G Mitrofanov,
D Golovin, [......],
A Rau,
D Smith,
J McTiernan,
R Schwartz, W Hajdas,
J Cummings,
D Palmer,
S Barthelmy,
N Gehrels,
H Krimm
GRB Coordinates Network. 01/2011; 12018:1.
-
K Hurley,
J Goldsten,
I ~G Mitrofanov,
D Golovin,
M ~L Litvak,
A ~B Sanin,
W Boynton,
C Fellows,
K Harshman,
H Enos, [......],
E Mazets,
V Pal'Shin,
D Frederiks,
D Svinkin,
T Cline,
D ~M Smith,
R ~P Lin,
J McTiernan,
R Schwartz, W Hajdas
GRB Coordinates Network. 01/2011; 12269:1.
-
K Hurley,
I ~G Mitrofanov,
D Golovin,
M ~L Litvak,
A ~B Sanin,
W Boynton,
C Fellows,
K Harshman,
H Enos,
R Starr, [......],
E Costa,
M ~E Del,
I Donnarumma,
Y Evangelista,
M Feroci,
I Lapshov,
F Lazzarotto,
L Pacciani,
M Rapisarda,
P Soffitta
GRB Coordinates Network. 01/2011; 12277:1.
-
K Hurley,
J Goldsten,
S Golenetskii,
R Aptekar,
E Mazets,
V Pal'Shin,
D Frederiks,
D Svinkin,
T Cline,
S Barthelmy,
J Cummings,
N Gehrels,
H Krimm,
D Palmer,
D ~M Smith,
R ~P Lin,
J McTiernan,
R Schwartz, W Hajdas
GRB Coordinates Network. 01/2011; 12299:1.
-
E. Suarez-Garcia,
D Haas, W. Hajdas,
G. Lamanna,
C Lechanoine-Leluc,
R. Marcinkowski,
A. Mtchedlishvili,
S. Orsi,
M Pohl,
N Produit,
D Rapin,
D. Rybka,
J P Vialle
[show abstract]
[hide abstract]
ABSTRACT: The hard X-ray polarimeter POLAR aims to measure the linear polarization of the 50-500 keV photons arriving from the prompt emission of gamma-ray bursts (GRBs). The position in the sky of the detected GRBs is needed to determine their level of polarization. We present here a method by which, despite of the polarimeter incapability of taking images, GRBs can be roughly localized using POLAR alone. For this purpose scalers are attached to the output of the 25 multi-anode photomultipliers (MAPMs) that collect the light from the POLAR scintillator target. Each scaler measures how many GRB photons produce at least one energy deposition above 50 keV in the corresponding MAPM. Simulations show that the relative outputs of the 25 scalers depend on the GRB position. A database of very strong GRBs simulated at 10201 positions has been produced. When a GRB is detected, its location is calculated searching the minimum of the chi2 obtained in the comparison between the measured scaler pattern and the database. This GRB localization technique brings enough accuracy so that the error transmitted to the 100% modulation factor is kept below 10% for GRBs with fluence Ftot \geq 10^(-5) erg cm^(-2) . The POLAR localization capability will be useful for those cases where no other instruments are simultaneously observing the same field of view. Comment: 13 pages, 10 figures
11/2010;
-
K. Hurley,
S. Golenetskii,
R. Aptekar,
E. Mazets,
V. Pal’shin,
D. Frederiks,
I. G. Mitrofanov,
D. Golovin,
M. L. Litvak,
A. B. Sanin, [......],
J. Cummings,
N. Gehrels,
H. Krimm,
J. Goldsten,
E. Del Monte,
M. Feroci,
M. Marisaldi,
M. Briggs,
V. Connaughton,
C. Meegan
[show abstract]
[hide abstract]
ABSTRACT: The 3rd interplanetary network (IPN), which has been in operation since 1990, presently consists of 9 spacecraft: AGILE, Fermi, RHESSI, Suzaku, and Swift, in low Earth orbit; INTEGRAL, in eccentric Earth orbit with apogee 0.5 light‐seconds; Wind, up to ∼7 light‐seconds from Earth; MESSENGER, en route to Mercury; and Mars Odyssey, in orbit around Mars. The IPN operates as a full‐time, all‐sky monitor for transients down to a threshold of about 6×10−7 erg cm−2 or 1 photon cm−2s−1. It detects ∼346 cosmic gamma‐ray bursts per year. These events are generally not the same ones detected by narrower field of view instruments such as Swift, INTEGRAL IBIS, and SuperAGILE; the localization accuracy is in the several arcminute and above range. The uses of the IPN data are described.
AIP Conference Proceedings. 10/2010; 1279(1):330-333.
-
[show abstract]
[hide abstract]
ABSTRACT: Semi-empirical fitting based on classical Bohr theory has been applied to the experimental LET data in silicon of the RADEF heavy ion cocktail species. The parameterized LET descriptions to be used in the European Component Irradiation Facilities are introduced and compared with the commonly used estimations from SRIM-code. Also, a new user interface, ECIF Cocktail Calculator, based on this work, has been published under the RADEF webpages at http://www.jyu.fi/accelerator/radef/ECIFCalc.
IEEE Transactions on Nuclear Science 09/2010; · 1.45 Impact Factor
-
K. Hurley,
A. Rowlinson,
E. Bellm,
D. Perley,
I. G. Mitrofanov,
D. V. Golovin,
A. S. Kozyrev,
M. L. Litvak,
A. B. Sanin,
W. Boynton, [......],
H. Krimm,
D. M. Palmer,
R. C. Duncan,
C. Wigger, W. Hajdas,
J.-L. Atteia,
G. Ricker,
R. Vanderspek,
A. Rau,
A. von Kienlin
[show abstract]
[hide abstract]
ABSTRACT: ABSTRACTGRB 051103 is considered to be a candidate soft gamma repeater (SGR) extragalactic giant magnetar flare by virtue of its proximity on the sky to M81/M82, as well as its time history, localization and energy spectrum. We have derived a refined interplanetary network localization for this burst which reduces the size of the error box by over a factor of 2. We examine its time history for evidence of a periodic component, which would be one signature of an SGR giant flare, and conclude that this component is neither detected nor detectable under reasonable assumptions. We analyse the time-resolved energy spectra of this event with improved time and energy resolution, and conclude that although the spectrum is very hard its temporal evolution at late times cannot be determined, which further complicates the giant flare association. We also present new optical observations reaching limiting magnitudes of R > 24.5, about 4-mag deeper than previously reported. In tandem with serendipitous observations of M81 taken immediately before and 1 month after the burst, these place strong constraints on any rapidly variable sources in the region of the refined error ellipse proximate to M81. We do not find any convincing afterglow candidates from either background galaxies or sources in M81, although within the refined error region we do locate two UV bright star-forming regions which may host SGRs. A supernova remnant (SNR) within the error ellipse could provide further support for an SGR giant flare association, but we were unable to identify any SNR within the error ellipse. These data still do not allow strong constraints on the nature of the GRB 051103 progenitor, and suggest that candidate extragalactic SGR giant flares will be difficult, although not impossible, to confirm.
Monthly Notices of the Royal Astronomical Society 01/2010; 403(1):342 - 352. · 4.90 Impact Factor
-
P Nieminen,
A Anastasiadis,
P Bühler,
I Daglis,
E Daly,
L Desorgher,
H Evans, W Hajdas,
J Lyons,
D Marinov,
others
38th COSPAR Scientific Assembly; 01/2010
-
[show abstract]
[hide abstract]
ABSTRACT: A sample of almost 400 Gamma-ray bursts (GRBs) detected by the RHESSI satellite is studied statistically. We focus on GRB duration and hardness ratio and use the statistical chi^2 test and the F-test to compare the number of GRB subgroups in the RHESSI database with that of the BATSE database. Although some previous articles based on the BATSE catalog claim the existence of an intermediate GRB subgroup, besides long and short, we have not found a statistically significant intermediate subgroup in the RHESSI data. Comment: Published in Proceedings of the 4th International Meeting on High Energy Gamma-Ray Astronomy
12/2009;
