Accurate early positions forSwiftGRBs: enhancing X-ray positions with UVOT astrometry
نویسندگان
چکیده
منابع مشابه
Radio astrometry with chromatic AGN core positions
Aims. The effect of frequency-dependent AGN core positions (“core-shifts”) on radio Very Long Baseline Interferometry (VLBI) global astrometry measurements is investigated. Methods. The basic equations relating to VLBI astrometry are reviewed, including the effects of source structure. A power-law representation of core-shifts, based on both observations and theoretical considerations of jet co...
متن کاملPositions and sizes of X-ray solar flare sources
Aims. The positions and source sizes of X-ray sources taking into account Compton backscattering (albedo) are investigated. Methods. Using a Monte Carlo simulation of X-ray photon transport including photo-electric absorption and Compton scattering, we calculate the apparent source sizes and positions of X-ray sources at the solar disk for various source sizes, spectral indices and directivitie...
متن کاملPeripheral Positions in Early Greek
This paper aims to provide a new approach to the development of clause structure in L1 acquisition on the basis of the distinction between LF-interpretable and LFuninterpretable features which is argued to have effects on learnability. The study concentrates on the acquisition of syntactic phenomena which are related to the syntax / pragmatics interface, namely focusing, dislocation and clitic-...
متن کاملLuminous Galaxies near Gamma-ray Burst Positions
The isotropic, inhomogeneous distribution of gamma-ray bursts (GRBs) suggests a cosmological origin. We are performing a deep J (1.25 mm), H (1.65 mm), and K9 (2.11 mm) imaging survey of the smallest GRB error boxes from the third Interplanetary Network to examine the extragalactic content of these regions. Relatively bright galaxies are seen in each of six GRB error boxes imaged to date. It is...
متن کاملAccurate and automatic surveying of beacon positions for a laserguided
In this paper we outline a system for automatic surveying of beacon positions for an autonomous guided vehicle. The vehicle measures the bearing to retro-reeective beacons using a laser scanner. As the vehicle moves, asynchronous measurements to unidenti-ed beacons are obtained. The goal of the system is to automatically group those measurements that belong to the same beacons, to nd all the er...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2007
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20078436