7 research outputs found
BDRG and shok instruments for study of GRB prompt emission in michaylo lomonosov space mission
The study of GRB prompt emission (PE) is one of the main goals of the Lomonosov
space mission, which is being prepared at Moscow State University. The GRB
monitor (BDRG) and the wide-field optical cameras (SHOK) are intended for detection of GRB
prompt emission as well as optical counterparts. The BDRG instrument consists of three
identical NaI(Tl)/CsI(Tl) (13.0Â ĂÂ 2.0cm ) phoswich detectors, whose axes determine the
Cartesian coordinate system. This allows to localize any GRB source on the sky by means of
the count rate seen by each detector with an accuracy of ~2 deg. The SHOK
instrument consists of two identical wide-field cameras (WFC) directed in such a way that
the field of view (FOV) of each WFC overlaps by the corresponding BDRG FOV, which produces
a trigger on the WFC in case of a GRB detection. With this setup, the GRB prompt light
curve will be obtained in the visible without any delay with respect to gamma-rays, which
is crucial for a GRB central engine understanding
Space experiments on-board of lomonosov mission to study gamma-ray bursts and UHECRS
The number of experiments on-board Lomonosov spacecraft are preparing now at SINP MSU in
co-operation with other organisations. The main idea of Lomonosov mission is to study
extreme astrophysical phenomena, such as cosmic gamma-ray bursts and ultra-high energy
cosmic rays. These phenomena connect with processes occurred in very distant astrophysical
objects of the Early Universe and give us information about first stages of Universe
evolution. Thus, the Lomonosov mission scientific equipment includes several instruments
for gamma-ray burst observation in optics, ultra-violet, X-rays and gamma-rays and the
wide aperture telescope for ultra-high energy particle study by detection of ionisation
light along its tracks in the atmosphere. The main parameters and a brief description of
these instruments are presented
Early polarization observations of the optical emission of gamma-ray bursts: GRB 150301B and GRB 150413A
We report early optical linear polarization observations of two gamma-ray burstsmade with the MASTER robotic telescope network. We found the minimum polarization for GRB 150301B to be 8 per cent at the beginning of the initial stage, whereas we detected no polarization for GRB 150413A either at the rising branch or after the burst reached the power-law afterglow stage. This is the earliest measurement of the polarization (in cosmological rest frame) of gamma-ray bursts. The primary intent of the paper is to discover optical emission and publish extremely rare (unique) high-quality light curves of the prompt optical emission of gammaray bursts during the non-monotonic stage of their evolution. We report that our team has discovered the optical counterpart of one of the bursts, GRB 150413A.Fil: Gorbovskoy, E.S.. Lomonosov Moscow State University; Rusia. Moscow State University; RusiaFil: Lipunov, V.M.. Lomonosov Moscow State University; . Moscow State University; RusiaFil: Buckley, D. A. H.. South African Astronomical Observatory; SudĂĄfricaFil: Kornilov, V. G.. Lomonosov Moscow State University; Rusia. Moscow State University; RusiaFil: Balanutsa, P. V.. Lomonosov Moscow State University; Rusia. Moscow State University; RusiaFil: Tyurina, N. V.. Lomonosov Moscow State University; Rusia. Moscow State University; RusiaFil: Kuznetsov, A. S.. Lomonosov Moscow State University; Rusia. Moscow State University; RusiaFil: Kuvshinov, D. A.. Lomonosov Moscow State University; Rusia. Moscow State University; RusiaFil: Gorbunov, I. A.. Lomonosov Moscow State University
; Rusia. Sternberg Astronomical Institute, Moscow State University; RusiaFil: Vlasenko, D.. Lomonosov Moscow State University; RusiaFil: Popova, E.. Lomonosov Moscow State University; Ruanda. Sternberg Astronomical Institute; RusiaFil: Chazov, V. V.. Sternberg Astronomical Institute; Rusia. Lomonosov Moscow State University; RusiaFil: Potter, S.. South African Astronomical Observatory; SudĂĄfricaFil: Kotze, M.. South African Astronomical Observatory; SudĂĄfricaFil: Kniazev, A. Y.. South African Astronomical Observatory; SudĂĄfrica. Southern African Large Telescope Foundation; SudĂĄfricaFil: Gress, O. A.. Irkutsk State University; RusiaFil: Budnev, N. M.. Irkutsk State University; RusiaFil: Ivanov, K. I.. Irkutsk State University; RusiaFil: Yazev, S. A.. Irkutsk State University; RusiaFil: Tlatov, A. G.. Kislovodsk Solar Station of the Pulkovo Observatory RAS; RusiaFil: Senik, V. A.. Lomonosov Moscow State University; Rusia. Sternberg Astronomical Institute; Rusia. Kislovodsk Solar Station of the Pulkovo Observatory RAS; RusiaFil: Dormidontov, D. V.. Lomonosov Moscow State University; Rusia. Sternberg Astronomical Institute; Rusia. Kislovodsk Solar Station of the Pulkovo Observatory RAS; RusiaFil: Parhomenko, A. V.. Lomonosov Moscow State University; . Pulkovo Observatory Of The Russian Academy Of Sciences; . Sternberg Astronomical Institute; RusiaFil: Krushinski, V. V.. Kislovodsk Solar Station of the Pulkovo Observatory RAS; RusiaFil: Zalozhnich, I. S.. Kislovodsk Solar Station of the Pulkovo Observatory RAS; RusiaFil: Castro Tirado, R. Alberto. Consejo Superior de Investigaciones CientĂficas; EspañaFil: SĂĄnchez RamĂrez, R.. Consejo Superior de Investigaciones CientĂficas; EspañaFil: Sergienko, Yu.P.. Blagoveschensk Educational State University; RusiaFil: Gabovich, A.. Blagoveschensk Educational State University; RusiaFil: Yurkov, V.V.. Blagoveschensk Educational State University; RusiaFil: Levato, Orlando Hugo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan. Instituto de Ciencias AstronĂłmicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias AstronĂłmicas, de la Tierra y del Espacio; ArgentinaFil: Saffe, Carlos. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan. Instituto de Ciencias AstronĂłmicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias AstronĂłmicas, de la Tierra y del Espacio; ArgentinaFil: Mallamaci, Claudio Carlos. Observatorio Astronmico FĂ©lix Aguilar; ArgentinaFil: Lopez, C.. Universidad Nacional de San Juan. Facultad de Ciencias Exactas FĂsicas y Naturales. Departamento de InformĂĄtica. Observatorio AstronĂłmico FĂ©lix Aguilar; ArgentinaFil: Podesta, F.. Universidad Nacional de San Juan. Facultad de Ciencias Exactas FĂsicas y Naturales. Departamento de InformĂĄtica. Observatorio AstronĂłmico FĂ©lix Aguilar; ArgentinaFil: Vladimirov, V. V.. Lomonosov Moscow State University; Rusia. Sternberg Astronomical Institute, Moscow State University; Rusi
Multi-messenger Observations of a Binary Neutron Star Merger
International audienceOn 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg(2) at a luminosity distance of Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 . An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over âŒ10 days. Following early non-detections, X-ray and radio emission were discovered at the transientâs position and days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta