Документ взят из кэша поисковой машины. Адрес
оригинального документа
: http://www.iki.rssi.ru/comp/2010/Pozanenko.htm
Дата изменения: Mon Nov 15 18:44:57 2010 Дата индексирования: Tue Oct 2 07:25:38 2012 Кодировка: Windows-1251 Поисковые слова: п п п п п п п п п п п п п п п п п п п |
Цикл работ на конкурс статей
'Исследование оптического проявления космических гамма-всплесков с помощью сети наблюдения за гамма-всплесками, объединяющей телескопы стран СНГ'
Аннотация
В шести работах цикла, опубликованных в 2008-2010 гг., приведены результаты наблюдения, исследования и интерпретации различных оптических проявлений гамма-всплесков: излучения в их активной фазе (GRB 060111B), послесвечения (GRB 060111B, GRB 070419A, GRB 080319B), поиска и исследования родительских галактик (GRB 920925C, GRB 051008, GRB 060111B) и исследование загадочных 'темных' гамма-всплесков, не обладающих оптическим послесвечением (GRB 051008). В заключительной работе цикла (The Afterglows of Swift-era Gamma-ray Bursts. I. ) статистически исследованы кривые блеска большого числа гамма-всплесков и найдены характерные особенности оптического излучения в различных его фазах. Причем около 20% данных для данного статистического анализа было получено на телескопах сети наблюдения за гамма-всплесками, организованной ИКИ РАН и объединяющей следующие телескопы (обсерватории): 50 см телескоп (Уссурийская Астрофизическая обсерватория), АЗТ-33ИК (ИСЗФ СО РАН), АЗТ-22 (г.Майданак, Институт Астрономии Уз. АН), Цейсс-2000, Цейсс-600 (пик Терскол, ИНАСАН), АЗТ-8, АЗТ-11, Цейсс-1000, ЗТШ (КрАО), Цейсс-600, ЗТЭ (Южная станция ГАИШ), а также наблюдения, проводимые на телескопе NOT (Испания) по заявкам ИКИ РАН.
1.
Stratta, G.;
Pozanenko, A.; Atteia, J.-L.;
Klotz, A.;
Basa, S.;
Gendre, B.;
Verrecchia, F.;
Boër, M.;
Cutini, S.;
Henze, M.;
Holland, S.;
Ibrahimov, M.;
Ienna, F.;
Khamitov, I.;
Klose, S.;
Rumyantsev, V.;
Biryukov, V.;
Sharapov, D.;
Vachier, F.;
Arnouts, S.;
Perley, D. A.
A
multiwavelength study of Swift GRB 060111B constraining the origin of its
prompt optical emission
Astronomy
and Astrophysics, Volume 503, Issue 3, 2009, pp.783-795
Publication Date: 09/2009
Context:
The detection of bright optical emission measured with good temporal resolution
during the prompt phase of GRB 060111Bmakes this GRB a rare event that is
especially useful for constraining theories of the prompt emission.
Aims: For this reason an extended multi-wavelength campaign was performed to
further constrain the physical interpretation of the observations.
Methods: In this work, we present the results obtained from our
multi-wavelength campaign, as well as from the public Swift/BAT, XRT, and UVOT
data.
Results: We identified the host galaxy at R˜25 mag from deep R-band
exposures taken 5 months after the trigger. Its featureless spectrum and
brightness, as well as the non-detection of any associated supernova 16 days
after the trigger, enabled us to constrain the distance scale of GRB 060111B11
within 0.4≤ z ≤3 in the most conservative case. The host galaxy
spectral continuum is best fit with a redshift of z~2, and other independent
estimates converge to z~1-2. From the analysis of the early afterglow SED, we
find that non-negligible host galaxy dust extinction, in addition to the
Galactic one, affects the observed flux in the optical regime. The
extinction-corrected optical-to-gamma-ray SED during the prompt emission shows
a flux density ratio Fγ/F_opt=10-2-10-4 with
spectral index βγ,opt > βγ, strongly suggesting a separate
origin of the optical and gamma-ray components. This result is supported by the
lack of correlated behavior in the prompt emission light curves observed in the
two energy domains. The temporal properties of the prompt optical emission
observed during GRB 060111B11 and their similarities to other rapidly-observed
events favor interpretation of this optical light as radiation from the reverse
shock. Observations are in good agreement with theoretical expectations for a
thick shell limit in slow cooling regime. The expected peak flux is consistent
with the observed one corrected for the host extinction, likely indicating that
the starting time of the TAROT observations is very near to or coincident with
the peak time. The estimated fireball initial Lorentz factor is Γ≥260-360 at z=1-2, similar to
the Lorentz factors obtained from other GRBs. GRB 060111B11 is a rare case of a
GRB with both a bright, well-observed optical counterpart and a 'canonical'
early X-ray light curve, thus providing a good test case of the reverse shock
emission mechanism in both energy ranges.
2.
Pozanenko, A. S.; Rumyantsev, V. V.; Loznikov, V. M.; Volnova, A. A.; Shulga, A. P.
Searching for the host galaxy of GRB 920925C
Astronomy
Letters, Volume 34, Issue 3, pp.141-144
Publication Date: 03/2008
GRB 920925C
is probably the first cosmic gamma-ray burst with an optical afterglow detected
from archival data. We present the results of our observations with the Shajn
mirror telescope of the Crimean Astrophysical Observatory aimed at searching
for the host galaxy at the afterglow location; we have determined the
boundaries of distances to the possible host galaxy.
3.
Melandri, A.; Guidorzi, C.; Kobayashi, S.; Bersier, D.; Mundell, C. G.; Milne, P.; Pozanenko, A.; Li, W.; Filippenko, A. V.; Urata, Y.; Ibrahimov, M.; Steele, I. A.; Gomboc, A.; Smith, R. J.; Tanvir, N. R.; Rol, E.; Huang, K.
Evidence
for energy injection and a fine-tuned central engine at optical wavelengths in
GRB 070419A
Monthly Notices of the Royal Astronomical Society, Volume 395, Issue 4, pp. 1941-1949
Publication Date: 06/2009
We present
a comprehensive multiwavelength temporal and spectral analysis of the `fast
rise exponential decay' GRB 070419A. The early-time emission in the γ-ray and X-ray bands can be
explained by a central engine active for at least 250 s, while at late times
the X-ray light curve displays a simple power-law
decay. In contrast, the observed behaviour in the optical band is complex (from
102 up to 106 s). We investigate the light-curve
behaviour in the context of the standard forward/reverse shock model;
associating the peak in the optical light curve at ~450 s with the fireball
deceleration time results in a Lorenz factor Γ ~ 350 at this time. In contrast, the shallow
optical decay between 450 and 1500 s remains problematic, requiring a reverse
shock component whose typical frequency is above the optical band at the
optical peak time for it to be explained within the standard model. This
predicts an increasing flux density for the forward shock component until t ~ 4
× 106 s, inconsistent with the observed decay of the optical
emission from t ~ 104 s. A highly magnetized fireball is also ruled
out due to unrealistic microphysic parameters and predicted light-curve
behaviour that is not observed. We conclude that a long-lived central engine
with a finely tuned energy injection rate and a sudden cessation of the
injection is required to create the observed light curves, consistent with the
same conditions that are invoked to explain the plateau phase of canonical
X-ray light curves of γ-ray bursts.
4.
Kann, D. A.;
Klose, S.;
Zhang, B.;
Malesani, D.;
Nakar, E.;
Pozanenko, A.;
Wilson, A. C.;
Butler, N. R.;
Jakobsson, P.;
Schulze, S.;
Andreev, M.;
Antonelli, L. A.;
Bikmaev, I. F.;
Biryukov, V.;
Böttcher, M.;
Burenin, R. A.;
Castro Cerón, J. M.;
Castro-Tirado, A. J.;
Chincarini, G.;
Cobb, B. E.;
Covino, S.;
D'Avanzo, P.;
D'Elia, V.;
Della Valle, M.;
de Ugarte Postigo, A.;
Efimov, Yu.;
Ferrero, P.;
Fugazza, D.;
Fynbo, J. P. U.;
Gålfalk, M.;
Grundahl, F.;
Gorosabel, J.;
Gupta, S.;
Guziy, S.;
Hafizov, B.;
Hjorth, J.;
Holhjem, K.;
Ibrahimov, M.;
Im, M.;
Israel, G. L.;
Jeĺinek, M.;
Jensen, B. L.;
Karimov, R.;
Khamitov, I. M.;
Kiziloǧlu, Ü.; Klunko, E.;
Kubánek, P.;
Kutyrev, A. S.;
Laursen, P.;
Levan, A. J.;
Mannucci, F.;
Martin, C. M.;
Mescheryakov, A.;
Mirabal, N.;
Norris, J. P.;
Ovaldsen, J.-E.; Paraficz, D.;
Pavlenko, E.;
Piranomonte, S.;
Rossi, A.;
Rumyantsev, V.;
Salinas, R.;
Sergeev, A.;
Sharapov, D.;
Sollerman, J.;
Stecklum, B.;
Stella, L.;
Tagliaferri, G.;
Tanvir, N. R.;
Telting, J.;
Testa, V.;
Updike, A. C.;
Volnova, A.;
Watson, D.;
Wiersema, K.;
Xu, D.
The Afterglows of Swift-era Gamma-ray Bursts. I. Comparing pre-Swift and
Swift-era Long/Soft (Type II) GRB Optical Afterglows
The
Astrophysical Journal, Volume 720, Issue 2, pp. 1513-1558 (2010)
Publication Date:
09/2010
We have gathered optical photometry data from the literature on a large sample of Swift-era gamma-ray burst (GRB) afterglows including GRBs up to 2009 September, for a total of 76 GRBs, and present an additional three pre-Swift GRBs not included in an earlier sample. Furthermore, we publish 840 additional new photometry data points on a total of 42 GRB afterglows, including large data sets for GRBs 050319, 050408, 050802, 050820A, 050922C, 060418, 080413A, and 080810. We analyzed the light curves of all GRBs in the sample and derived spectral energy distributions for the sample with the best data quality, allowing us to estimate the host-galaxy extinction. We transformed the afterglow light curves into an extinction-corrected z = 1 system and compared their luminosities with a sample of pre-Swift afterglows. The results of a former study, which showed that GRB afterglows clustered and exhibited a bimodal distribution in luminosity space, are weakened by the larger sample. We found that the luminosity distribution of the two afterglow samples (Swift-era and pre-Swift) is very similar, and that a subsample for which we were not able to estimate the extinction, which is fainter than the main sample, can be explained by assuming a moderate amount of line-of-sight host extinction. We derived bolometric isotropic energies for all GRBs in our sample, and found only a tentative correlation between the prompt energy release and the optical afterglow luminosity at 1 day after the GRB in the z = 1 system. A comparative study of the optical luminosities of GRB afterglows with echelle spectra (which show a high number of foreground absorbing systems) and those without, reveals no indication that the former are statistically significantly more luminous. Furthermore, we propose the existence of an upper ceiling on afterglow luminosities and study the luminosity distribution at early times, which was not accessible before the advent of the Swift satellite. Most GRBs feature afterglows that are dominated by the forward shock from early times on. Finally, we present the first indications of a class of long GRBs, which form a bridge between the typical high-luminosity, high-redshift events and nearby low-luminosity events (which are also associated with spectroscopic supernovae) in terms of energetics and observed redshift distribution, indicating a continuous distribution overall.
5.
Pandey, S. B.;
Castro-Tirado, A. J.;
Jelínek, M.;
Kamble, A. P.;
Gorosabel, J.;
de Ugarte Postigo, A.;
Prins, S.;
Oreiro, R.;
Chantry, V.;
Trushkin, S.;
Bremer, M.;
Winters, J. M.;
Pozanenko, A.;
Krugly, Yu.;
Slyusarev, I.;
Kornienko, G.;
Erofeeva, A.;
Misra, K.;
Ramprakash, A. N.;
Mohan, V.;
Bhattacharya, D.;
Volnova, A.;
Plá, J.;
Ibrahimov, M.;
Im, M.;
Volvach, A.;
Wijers, R. A. M. J.
Multi-wavelength observations of the GRB 080319B afterglow and the modeling constraints
Astronomy and Astrophysics, Volume 504, Issue 1, 2009, pp.45-51
Publication Date: 09/2009
Context: We
present observations of the GRB 080319B afterglow at optical, mm, and radio
frequencies between a few hours and 67 days after the burst.
Aims: We attempt to understand the nature of this extraordinarily bright
explosion based on the observed properties and its comparison with afterglow
models.
Methods: Our observations and other published multiwavelength data were used to
reconstruct the light curves and spectral energy distributions of the burst
afterglow.
Results: Our results indicate that the observed features of the afterglow
agrees equally well with the inter stellar matter and
the stellar wind density profiles of the circumburst medium. In the case of
both density profiles, the maximum synchrotron frequency νm is below optical value and the cooling break
frequency νc is below X-rays, ~104 s
after the burst. The derived value of the Lorentz factor at the time of
naked-eye brightness is also ~300 for a corresponding blast-wave size of ~1018
cm.
Conclusions: The numerical fit to the multiwavelength afterglow data
constraints the values of physical parameters and the emission mechanism of the
burst.
6.
А.А.
Вольнова, А.С. Позаненко, В.В.
Румянцев, В.В. Бирюков, М.А. Ибрагимов, Д.А. Шарапов, Д.А. Канн, Х. Горосабль,
A.Х. Кастро-Тирадо, A. де Угарте Постиго
Родительская галактика темного гамма-всплеска GRB 051008.
принято к публикации в Астрофизический
Бюллетень, 2010,
Найдена и исследована родительская
галактика "темного" гамма-всплеска GRB051008
(βOX < 0.18) - всплеска, от которого не было зарегистрировано оптического
послесвечения. Исследованы свойства и определено красное смещение родительской
галактики z=1.07
+ 0.13, изучено ее окружение.
Приводится сравнительный анализ свойств GRB051008 и его родительской галактики
с другими известными темными гамма-всплесками.
Проведен анализ причин отсутствия оптического послесвечения у
данного гамма-всплеска.