0000000000121961
AUTHOR
S. Jeong
Ultra-Fast Flash Observatory for observation of early photons from gamma ray bursts
We describe the space project of Ultra-Fast Flash Observatory (UFFO) which will observe early optical photons from gamma-ray bursts (GRBs) with a sub-second optical response, for the first time. The UFFO will probe the early optical rise of GRBs, opening a completely new frontier in GRB and transient studies, using a fast response Slewing Mirror Telescope (SMT) that redirects optical path to telescope instead of slewing of telescopes or spacecraft. In our small UFFO-Pathfinder experiment, scheduled to launch aboard the Lomonosov satellite in 2012, we use a motorized mirror in our Slewing Mirror Telescope instrument to achieve less than one second optical response after X-ray trigger. We des…
A Decade of GRB Follow-Up by BOOTES in Spain (2003–2013)
This article covers ten years of GRB follow-ups by the Spanish BOOTES stations: 71 follow-ups providing 23 detections. Follow-ups by BOOTES-1B from 2005 to 2008 were given in a previous article and are here reviewed and updated, and additional detection data points are included as the former article merely stated their existence. The all-sky cameras CASSANDRA have not yet detected any GRB optical afterglows, but limits are reported where available.
The Ultra-Fast Flash Observatory's space GRB mission and science
AbstractThe Ultra-Fast Flash Observatory (UFFO) is a space mission to detect the early moments of an explosion from Gamma-ray bursts (GRBs), thus enhancing our understanding of the GRB mechanism. It consists of the UFFO Burst & Trigger telescope (UBAT) for the recognition of GRB positions using hard X-ray from GRBs. It also contains the Slewing Mirror Telescope (SMT) for the fast detection of UV-optical photons from GRBs. It is designed to begin the UV-optical observations in less than a few seconds after the trigger. The UBAT is based on a coded-mask X-ray camera with a wide field of view (FOV) and is composed of the coded mask, a hopper and a detector module. The SMT has a fast rotata…
Development of Motorized Slewing Mirror Stage for the UFFO Project
The Ultra-Fast Flash Observatory (UFFO) is a space observatory for optical follow-ups of gamma ray bursts (GRBs), aiming to explore the first 60 seconds of GRBs optical emission. UFFO is utilized to catch early optical emissions from GRBs within few sec after trigger using a Gimbal mirror which redirects the optical path rather than slewing entire spacecraft. We have developed a 15 cm two-axis Gimbal mirror stage for the UFFO-Pathfinder which is going to be on board the Lomonosov satellite which is to be launched in 2013. The stage is designed for fast and accurate motion with given budgets of 3 kg of mass and 3 Watt of power. By employing stepping motors, the slewing mirror can rotate fast…
Ultra-Fast Flash Observatory for detecting the early photons from gamma-ray bursts
Gamma-ray bursts (GRBs) are the most luminous transient events with short intense flashes that have been detected in random directions in the sky once or twice per day. Their durations have been measured in seconds, especially short GRBs with duration of < 2 sec. The Ultra-Fast Flash Observatory (UFFO) space mission aims to detect the earliest moments of an explosion which presents the nature of GRBs, resulting into the enhancement of GRB mechanism understanding. The UFFO consists of a couple of wide Field-of-View (FOV) trigger telescopes, a narrow-FOV Slewing Mirror Telescope (SMT) for the fast measurement of the UV-optical photons from GRBs, and a gamma-ray monitor for energy measurement.…
The Status of the Ultra Fast Flash Observatory - Pathfinder
On behalf of the UFFO Collaboration; International audience; The Ultra Fast Flash Observatory (UFFO) is a project to study early optical emissions from Gamma Ray Bursts (GRBs). The primary scientific goal of UFFO is to see if GRBs can be calibrated with their rising times, so that they could be used as new standard candles. In order to minimize delay in optical follow-up measurements, which is now about 100 sec after trigger from the Swift experiment, we rotate a mirror to redirect light path so that optical measurement can be performed within a second after the trigger. We have developed a pathfinder mission, UFFO-pathfinder to launch on board the Lomonosov satellite in 2012. In this talk,…
Ultra-Fast Flash Observatory: Fast Response Space Missions for Early Time Phase of Gamma Ray Bursts
One of the unexplored domains in the study of gamma-ray bursts (GRBs) is the early time phase of the optical light curve. We have proposed Ultra-Fast Flash Observatory (UFFO) to address this question through extraordinary opportunities presented by a series of small space missions. The UFFO is equipped with a fast-response Slewing Mirror Telescope that uses a rapidly moving mirror or mirror array to redirect the optical beam rather than slewing the entire spacecraft or telescope to aim the optical instrument at the GRB position. The UFFO will probe the early optical rise of GRBs with sub-second response, for the first time, opening a completely new frontier in GRB and transient studies. Its…
Calibration and Simulation of the GRB trigger detector of the Ultra Fast Flash Observatory
The UFFO (Ultra-Fast Flash Observatory) is a GRB detector on board the Lomonosov satellite, to be launched in 2013. The GRB trigger is provided by an X-ray detector, called UBAT (UFFO Burst Alarm & Trigger Telescope), which detects X-rays from the GRB and then triggers to determine the direction of the GRB and then alerts the Slewing Mirror Telescope (SMT) to turn in the direction of the GRB and record the optical photon fluxes. This report details the calibration of the two components: the MAPMTs and the YSO crystals and simulations of the UBAT. The results shows that this design can observe a GRB within a field of view of ±35° and can trigger in a time scale as short as 0.2 – 1.0 s af…
In-Flight Calibrations of UFFO-Pathfinder
The Ultra-Fast Flash Observatory (UFFO), which will be launched onboard the Lomonosov spacecraft, contains two crucial instruments: UFFO Burst Alert & Trigger Telescope (UBAT) for detection and localization of Gamma-Ray Bursts (GRBs) and the fast-response Slewing Mirror Telescope (SMT) designed for the observation of the prompt optical/UV counterparts. Here we discuss the in-space calibrations of the UBAT detector and SMT telescope. After the launch, the observations of the standard X-ray sources such as pulsar in Crab nebula will provide data for necessary calibrations of UBAT. Several standard stars will be used for the photometric calibration of SMT. The celestial X-ray sources, e.g.…
Design and implementation of electronics and data acquisition system for Ultra-Fast Flash Observatory
The Ultra-Fast Flash Observatory (UFFO) Pathfinder for Gamma-Ray Bursts (GRBs) consists of two telescopes. The UFFO Burst Alert & Trigger Telescope (UBAT) handles the detection and localization of GRBs, and the Slewing Mirror Telescope (SMT) conducts the measurement of the UV/optical afterglow. UBAT is equipped with an X-ray detector, analog and digital signal readout electronics that detects X-rays from GRBs and determines the location. SMT is equipped with a stepping motor and the associated electronics to rotate the slewing mirror targeting the GRBs identified by UBAT. First the slewing mirror points to a GRB, then SMT obtains the optical image of the GRB using the intensified CCD an…
The readout system and the trigger algorithm implementation for the UFFO Pathfinder
Since the launch of the SWIFT, Gamma-Ray Bursts (GRBs) science has been much progressed. Especially supporting many measurements of GRB events and sharing them with other telescopes by the Gamma-ray Coordinate Network (GCN) have resulted the richness of GRB events, however, only a few of GRB events have been measured within a minute after the gamma ray signal. This lack of sub-minute data limits the study for the characteristics of the UV-optical light curve of the short-hard type GRB and the fast-rising GRB. Therefore, we have developed the telescope named the Ultra-Fast Flash Observatory (UFFO) Pathfinder, to take the sub-minute data for the early photons from GRB. The UFFO Pathfinder has…
Design, Construction and Performance of the Detector for UFFO Burst Alert & Trigger Telescope
One of the key aspects of the upcoming Ultra-Fast Flash Observatory (UFFO) pathfinder for Gamma Ray Bursts (GRBs) identification is the UFFO Burst Alert & Trigger Telescope (UBAT). The scientific propose of UBAT is to detect and locate as fast as possible the GRBs in the sky. This is achieved by using a coded mask aperture camera scheme with a wide field of view (FOV) and selecting a X-ray detector of high quantum efficiency and large detection area. This X-ray detector of high quantum efficiency and large detection area is called the UBAT detector. The UBAT detector consists of 48 × 48 Yttrium Oxyorthosilicate (YSO) scintillator crystal arrays and Multi Anode Photomultiplier Tubes (MAPMTs)…
Readout of the UFFO Slewing Mirror Telescope to detect UV/optical photons from Gamma-Ray Bursts
The Slewing Mirror Telescope (SMT) was proposed for rapid response to prompt UV/optical photons from Gamma-Ray Bursts (GRBs). The SMT is a key component of the Ultra-Fast Flash Observatory (UFFO)-pathfinder, which will be launched aboard the Lomonosov spacecraft at the end of 2013. The SMT utilizes a motorized mirror that slews rapidly forward to its target within a second after triggering by an X-ray coded mask camera, which makes unnecessary a reorientation of the entire spacecraft. Subsequent measurement of the UV/optical is accomplished by a 10 cm aperture Ritchey-Chretien telescope and the focal plane detector of Intensified Charge-Coupled Device (ICCD). The ICCD is sensitive to UV/opt…
Development of Slewing Mirror Telescope Optical System for the UFFO-pathfinder
The Slewing Mirror Telescope (SMT) is the UV/optical telescope of UFFO-pathfinder. The SMT optical system is a Ritchey-Chretien (RC) telescope of 100 mm diameter pointed by means of a gimbal-mounted flat mirror in front of the telescope. The RC telescope has a 17 × 17arcmin2 in Field of View and 4.3 arcsec resolution (full width half maximum of the point spread function) The beam-steering mirror enables the SMT to access a 35 × 35degree region and point and settle within 1 sec. All mirrors were fabricated to about 0.02 wavelengths RMS in wave front error (WFE) and 84.7% average reflectivity over 200 nm ~ 650 nm. The RC telescope was aligned to 0.05 wavelengths RMS in WFE (test wavelength 63…
ULTRA-FAST FLASH OBSERVATORY (UFFO) FOR OBSERVATION OF EARLY PHOTONS FROM GAMMA RAY BURSTS
I.H. Park, S. Ahmad, P. Barrillon, S. Brandt, C. Budtz-Jorgensen, A.J. Castro-Tirado, P. Chen, Y.J. Choi, P. Connell, S. Dagoret-Campagne, C. Eyles, B. Grossan, M.–H.A. Huang, A. Jung, S. Jeong, J.E. Kim, M.B. Kim, S.-W. Kim, Y.W. Kim, A.S. Krasnov, J. Lee, H. Lim, E.V. Linder, T.–C. Liu, N. Lund, K.W. Min, G.W. Na, J.W. Nam, M.I. Panasyuk, J. Ripa, V. Reglero, J.M. Rodrigo, G.F. Smoot, J.E. Suh, S. Svertilov, N. Vedenkin, M.–Z. Wang, I. Yashin Ewha Womans University, Seoul, Korea University of Paris-Sud 11, Orsay, France Technical University of Denmark, Copenhagen, Denmark Instituto de Astrofisica de Andalucia CSIC, Granada, Spain National Taiwan University, Taipei, Taiwan Korea Advanced I…
The slewing mirror telescope of the Ultra Fast Flash Observatory Pathfinder
The Slewing Mirror Telescope (SMT) is a key telescope of Ultra-Fast Flash Observatory (UFFO) space project to explore the first sub-minute or sub-seconds early photons from the Gamma Ray Bursts (GRBs) afterglows. As the realization of UFFO, 20kg of UFFO-Pathfinder (UFFO-P) is going to be on board the Russian Lomonosov satellite in November 2012 by Soyuz-2 rocket. Once the UFFO Burst Alert & Trigger Telescope (UBAT) detects the GRBs, Slewing mirror (SM) will slew to bring new GRB into the SMT’s field of view rather than slewing the entire spacecraft. SMT can give a UV/Optical counterpart position rather moderated 4arcsec accuracy. However it will provide a important understanding of the GRB …
In-Situ Calibration of UFFO/Lomonosov for Observation of GRBs
The UFFO/Lomonosov has been successfully launched into Sun synchronous orbit and is operational through tests and calibrations since its launch on Apr. 28, 2016. As a pathfinder of UFFO, it will be the first space instrument to use a fast slewing mirror which reduce the trigger latency of optical telescope, less than a second, to explore early time domain of GRB evolution. In this article, we will report in detail the first mission, UFFO/Lomonosov, for the rapid response to observe early photons from GRBs in orbit.
Design and implementation of the UFFO burst alert and trigger telescope
The Ultra Fast Flash Observatory pathfinder (UFFO-p) is a telescope system designed for the detection of the prompt optical/UV photons from Gamma-Ray Bursts (GRBs), and it will be launched onboard the Lomonosov spacecraft in 2012. The UFFO-p consists of two instruments: the UFFO Burst Alert and Trigger telescope (UBAT) for the detection and location of GRBs, and the Slewing Mirror Telescope (SMT) for measurement of the UV/optical afterglow. The UBAT isa coded-mask aperture X-ray camera with a wide field of view (FOV) of 1.8 sr. The detector module consists of the YSO(Yttrium Oxyorthosilicate) scintillator crystal array, a grid of 36 multi-anode photomultipliers (MAPMTs), and analog and digi…
Prompt and Follow-up Multi-wavelength Observations of the GRB 161017A
This paper presents data on the simultaneous and complementary observations of the gamma-ray burst (GRB) GRB 161017A for optical, X-ray, and gamma wavelengths obtained by the Russian multi-messenger Lomonosov space observatory and supplemented by additional data from the Swift satellite as well as the ground-based MASTER Global Robotic Net and the 10 m Gran Telescopio Canarias. Multifrequency spectra of this very powerful explosion indicate that it originated at a distance of 10 billion light years from Earth. Here, we present the results of the prompt, early, and afterglow optical observations. The light curves and spectra suggest that the prompt optical and high-energy emissions occur in …
Inverted-conical light guide for crosstalk reduction in tightly-packed scintillator matrix and MAPMT assembly
Abstract In this paper we present the Inverted-Conical light guide designed for optical crosstalk reduction in the scintillator-MAPMT assemblies. The research was motivated by the 30% crosstalk observed in UFFO X-ray telescope , UBAT, during the preliminary calibration with MAPMTs of 64 2.88 × 2.88 mm2 pixels and identically gridded YSO crystal matrices. We began the study with the energy and crosstalk calibrations of the detector, then we constructed a GEANT4 simulation with the customized metallic film model as the MAPMT photocathode . The simulation reproduced more than 70% of the crosstalk and explained it as a consequence of the total reflection produced by the photocathode. The result…
Ultra-Fast Flash Observatory for the observation of early photons from gamma-ray bursts
One of the least documented and understood aspects of gamma-ray bursts (GRBs) is the rise phase of the optical light curve. The Ultra-Fast Flash Observatory (UFFO) is an effort to address this question through extraordinary opportunities presented by a series of space missions including a small spacecraft observatory. The UFFO is equipped with a fast-response Slewing Mirror Telescope (SMT) that uses a rapidly moving mirror or mirror array to redirect the optical beam rather than slewing the entire spacecraft to aim the optical instrument at the GRB position. The UFFO will probe the early optical rise of GRBs with sub-second response, for the first time, opening a completely new frontier in …
A next generation Ultra-Fast Flash Observatory (UFFO-100) for IR/optical observations of the rise phase of gamma-ray bursts
The Swift Gamma-ray Burst (GRB) observatory responds to GRB triggers with optical observations in ~ 100 s, but cannot respond faster than ~ 60 s. While some ground-based telescopes respond quickly, the number of sub-60 s detections remains small. In mid- to late-2013, the Ultra-Fast Flash Observatory-Pathfinder is to be launched on the Lomonosov spacecraft to investigate early optical GRB emission. This pathfinder mission is necessarily limited in sensitivity and event rate; here we discuss a next generation rapid-response space observatory. We list science topics motivating our instruments, those that require rapid optical-IR GRB response, including: A survey of GRB rise shapes/times, meas…
Slewing Mirror Telescope and the Data-Acquisition System for the UFFO-Pathfinder
The Ultra-Fast Flash Observatory (UFFO) aims to detect the earliest moment of Gamma-Ray Bursts (GRBs) which is not well known, resulting into the enhancement of GRB mechanism understanding. The pathfinder mission was proposed to be a scaled-down version of UFFO, and only contains the UFFO Burst Alert & Trigger Telescope (UBAT) measuring the X-ray/gamma-ray with the wide-field of view and the Slewing Mirror Telescope (SMT) with a rapid-response for the UV/optical photons. Once the UBAT detects a GRB candidate with the position accuracy of 10 arcmin, the SMT steers the UV/optical photons from the candidate to the telescope by the fast rotatable mirror and provides the early UV/optical pho…
Design and Fabrication of Detector Module for UFFO Burst Alert & Trigger Telescope
The Ultra-Fast Flash Observatory (UFFO) pathfinder is a space mission devoted to the measurement of Gamma-Ray Bursts (GRBs), especially their early light curves which will give crucial information on the progenitor stars and central engines of the GRBs. It consists of two instruments: the UFFO Burst Alert & Trigger telescope (UBAT) for the detection of GRB locations and the Slewing Mirror Telescope (SMT) for the UV/optical afterglow observations, upon triggering by UBAT. The UBAT employs a coded-mask {\gamma}/X-ray camera with a wide field of view (FOV), and is comprised of three parts: a coded mask, a hopper, and a detector module (DM). The UBAT DM consists of a LYSO scintillator crystal a…
THE UFFO SLEWING MIRROR TELESCOPE FOR EARLY OPTICAL OBSERVATION FROM GAMMA RAY BURSTS
While some space born observatories, such as SWIFT and FERMI, have been operating, early observation of optical after grow of GRBs is still remained as an unexplored region. The Ultra-Fast Flash Observatory (UFFO) project is a space observatory for optical follow-ups of GRBs, aiming to explore the first 60 seconds of GRBs optical emission. Using fast moving mirrors to redirect our optical path rather than slewing the entire spacecraft, UFFO is utilized to catch early optical emissions from GRB within 1 sec. We have developed the UFFO Pathfinder Telescope which is going to be on board of the Lomonosov satellite and launched in middle of 2012. We will discuss about scientific potentials of t…