Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userFirst flight of the Gamma-Ray Imager/Polarimeter for Solar flares (GRIPS) instrument
65
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The Gamma-Ray Imager/Polarimeter for Solar flares (GRIPS) is a balloon-borne telescope designed to study solar-flare particle acceleration and transport. We describe GRIPSs first Antarctic long-duration flight in Jan 2016 and report preliminary calibration and science results. Electron and ion dynamics, particle abundances and the ambient plasma conditions in solar flares can be understood by examining hard X-ray (HXR) and gamma-ray emission (20 keV to 10 MeV) with enhanced imaging, spectroscopy and polarimetry. GRIPS is specifically designed to answer questions including: What causes the spatial separation between energetic electrons producing HXRs and energetic ions producing gamma-ray lines? How anisotropic are the relativistic electrons, and why can they dominate in the corona? How do the compositions of accelerated and ambient material vary with space and time, and why? GRIPSs key technological improvements over the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) include 3D position-sensitive germanium detectors (3D-GeDs) and a single-grid, multi-pitch rotating modulator (MPRM) collimator. The 3D-GeDs have spectral FWHM resolution of a few hundred keV and spatial resolution $<$1 mm$^3$. For photons that Compton scatter, usually $gtrsim$150 keV, the energy deposition sites can be tracked, providing polarization measurements as well as enhanced background reduction. The MPRM single-grid design provides twice the throughput of a bi-grid imaging system like RHESSI. The grid is composed of 2.5 cm thick W/Cu slats with 1-13 mm variable slit pitch, achieving quasi-continuous FWHM angular coverage over 12.5-162 arcsecs. This resolution is capable of imaging the separate magnetic loop footpoint emissions in a variety of flare sizes. (Abstract edited down from source.)
rate research
Read More
The Sun is the nearest astrophysical source with a very intense emission in the X-ray band. The study of energetic events, such as solar flares, can help us to understand the behaviour of the magnetic field of our star. There are in the literature numerous studies published about polarization predictions, for a wide range of solar flares models involving the emission from thermal and/or non-thermal processes, but observations in the X-ray band have never been exhaustive. The gas pixel detector (GPD) was designed to achieve X-ray polarimetric measurements as well as X-ray images for far astrophysical sources. Here we present the possibility to employ this instrument for the observation of our Sun in the X-ray band.
As a Near-IR instrument to PRLs upcoming 2.5 m telescope, NISP is designed indigeniously at PRL to serve as a multifaceted instrument. Optical, Mechanical and Electronics subsystems are being designed and developed in-house at PRL. It will consist of imaging, spectroscopy and imaging-polarimetry mode in the wavelength bands Y, J, H, Ks i.e. 0.8 - 2.5 micron. The detector is an 2K x 2K H2RG (MCT) array detector from Teledyne, which will give a large FOV of 10 x 10 in the imaging mode. Spectroscopic modes with resolving power of R ~ 3000, will be achieved using grisms. Spectroscopy will be available in single order and a cross-dispersed mode shall be planned for simultaneous spectra. The instrument enables multi-wavelength imaging-polarimetry using Wedged-Double Wollaston (WeDoWo) prisms to get single shot Stokes parameters (I, Q, U) for linear polarisation simultaneously, thus increasing the efficiency of polarisation measurements and reducing observation time.
The prompt emission of GRBs has been investigated for more than 50 years but remains poorly understood. Commonly, spectral and temporal profiles of {gamma}-ray emission are analysed. However, they are insufficient for a complete picture on GRB-related physics. The addition of polarization measurements provides invaluable information towards the understanding of these astrophysical sources. In recent years, dedicated polarimeters, such as POLAR and GAP, were built. The former of which observed low levels of polarization as well as a temporal evolution of the polarization angle. It was understood that a larger sample of GRB polarization measurements and time resolved studies are necessary to constrain theoretical models. The POLAR-2 mission aims to address this by increasing the effective area by an order of magnitude compared to POLAR. POLAR-2 is manifested for launch on board the China Space Station in 2024 and will operate for at least 2 years. Insight from POLAR will aid in the improvement of the overall POLAR-2 design. Major improvements (compared to POLAR) will include the replacement of multi-anode PMTs (MAPMTs) with SiPMs, increase in sensitive volume and further technological upgrades. POLAR-2 is projected to measure about 50 GRBs per year with equal or better quality compared to the best seen by POLAR. The instrument design, preliminary results and anticipated scientific potential of this mission will be discussed.
As an in-house instrument developmental activity at ARIES, the 4Kx4K CCD Imager is designed and developed as a first-light instrument for the axial port of the 3.6m DOT. The f/9 beam of the telescope having a plate-scale of ~ 6.4 arc-sec/mm is utilized to conduct deeper photometry within the central 10 arc-min field of view. The pixel size of the blue-enhanced liquid Nitrogen cooled STA4150 4Kx4K CCD chip is 15 micron, with options to select gain and speed values to utilize the dynamic range. Using the Imager, it is planned to image the central ~ 6.5x6.5 arc-min^2 field of view of the telescope for various science goals by getting deeper images in several broad-band filters for point sources and objects with low surface brightness. The fully assembled Imager along with automated filter wheels having Bessel UBVRI and SDSS ugriz filters was tested in late 2015 at the axial port of the 3.6m DOT. This instrument was finally mounted at the axial port of the 3.6m DOT on 30th March 2016 when the telescope was technically activated jointly by the Prime Ministers of India and Belgium. This instrument is expected to serve as a general purpose multi-band deep imaging instrument for variety of science goals including studies of cosmic transients, active galaxies, star clusters and optical monitoring of X-ray sources discovered by the newly launched Indian space-mission called ASTROSAT and follow-up of radio bright objects discovered by the GMRT.
We describe plans for the development of the Southern Wide-field Gamma-ray Observatory (SWGO), a next-generation instrument with sensitivity to the very-high-energy (VHE) band to be constructed in the Southern Hemisphere. SWGO will provide wide-field coverage of a large portion of the southern sky, effectively complementing current and future instruments in the global multi-messenger effort to understand extreme astrophysical phenomena throughout the universe. A detailed description of science topics addressed by SWGO is available in the science case white paper [1]. The development of SWGO will draw on extensive experience within the community in designing, constructing, and successfully operating wide-field instruments using observations of extensive air showers. The detector will consist of a compact inner array of particle detection units surrounded by a sparser outer array. A key advantage of the design of SWGO is that it can be constructed using current, already proven technology. We estimate a construction cost of 54M USD and a cost of 7.5M USD for 5 years of operation, with an anticipated US contribution of 20M USD ensuring that the US will be a driving force for the SWGO effort. The recently formed SWGO collaboration will conduct site selection and detector optimization studies prior to construction, with full operations foreseen to begin in 2026. Throughout this document, references to science white papers submitted to the Astro2020 Decadal Survey with particular relevance to the key science goals of SWGO, which include unveiling Galactic particle accelerators [2-10], exploring the dynamic universe [11-21], and probing physics beyond the Standard Model [22-25], are highlighted in red boldface.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
