Suchergebnisse

Several algorithms are used nowadays for detecting stellar objects in astronomical images, for example in the DAOPHOTprogram package and in SExtractor (Software for source extraction). Our team has become acquainted with the wavelet transform and its good localization properties. After studying the manual for DAOPHOT and SExtractor, and becoming familiar with the trous algorithm used for calculating the wavelet transform, we set ourselves the task to implement an algorithm for star detection on the basis of the wavelet transform. We focused on detecting stellar objects in complex fields, such as globular clusters and galaxies. This paper describes a stellar object detection algorithm with the help ofthe wavelet transform, and presents our results.

The European Space Agency ESA INTEGRAL satellite launched in October 2002 is the first astrophysical satellite of the European Space Agency (ESA) with Czech participation. The results of the first 8 years of investigations of various scientific targets are briefly presented and discussed here, with emphasis on cataclysmic variables and blazars with the ESA INTEGRAL satellite with Czech participation.

We report on our efforts to formulate algorithms for image signal processing with the spatially and time variant Point-Spread Function (PSF) and inhomogeneous noise of real imaging systems. In this paper we focus on application of the wavelet transform for denoising of the astronomical images with complicated conditions. They influence above all accuracy of the measurements and the new source detection ability. Our aim is to test the usefulness ofWavelet transform (as the standard image processing technique) for astronomical purposes.

The ESA INTEGRAL satellite, launched in October 2002, is the first astrophysical satellite of the European Space Agency ESA with Czech participation. The results of the first 7 years of investigations of various scientific targets e.g. cataclysmic variables, blazars, X-ray sources, and GRBs with the ESA INTEGRAL satellite with Czech participation are briefly presented and discussed.

We present the Global Rapid Advanced Network Devoted to the Multi-messenger Addicts (GRANDMA). The network consists of 21 telescopes with both photometric and spectroscopic facilities. They are connected together thanks to a dedicated infrastructure. The network aims at coordinating the observations of large sky position estimates of transient events to enhance their follow-up and reduce the delay between the initial detection and optical confirmation. The GRANDMA programme mainly focuses on follow-up of gravitational-wave alerts to find and characterize the electromagnetic counterpart during the third observational campaign of the Advanced LIGO and Advanced Virgo detectors. But it allows for follow-up of any transient alerts involving neutrinos or gamma-ray bursts, even those with poor spatial localization. We present the different facilities, tools, and methods we developed for this network and show its efficiency using observations of LIGO/Virgo S190425z, a binary neutron star merger candidate.We furthermore report on allGRANDMAfollow-up observations performed during the first six months of the LIGO-Virgo observational campaign, and we derive constraints on the kilonova properties assuming that the events' locations were imaged by our telescopes. © 2019 The Author(s). ; Parts of this research were conducted by the Australian Research Council Centre of Excellence for Gravitational Wave Discovery (OzGrav), through project number CE170100004. EJH acknowledges support from a Australian Research Council DECRA Fellowship (DE170100891). AdUP and CCT acknowledge support from Ramon y Cajal fellowships RyC-2012-09975 and RyC-201209984 and the Spanish Ministry of Economy and Competitiveness through project AYA2017-89384-P. DAK acknowledges support from the Spanish research projectAYA2017-89384-P. MBacknowledges funding as `personal tecnico de apoyo' under fellowship number PTA2016-13192-I. MC is supported by the David and Ellen Lee Postdoctoral Fellowship at the California Institute of Technology. SA is supported by the CNES Postdoctoral Fellowship at Laboratoire AstroParticule et Cosmologie. SA, AC, CL, and RM acknowledge the financial support of the UnivEarthS Labex program at Sorbonne Paris Cite (ANR-10-LABX-0023 and ANR-11-IDEX-0005-02). SA and NL acknowledge the financial support of the Programme National Hautes Energies (PNHE). DT acknowledges the financial support of the Chinese Academy of Sciences (CAS) PIFI post-doctoral fellowship program (program C). UBAI acknowledges support from the Ministry of Innovative Development through projects FA-Atech-2018-392 and VA-FAF-2-010. IRiS has been carried out thanks to the support of the OCEVU Labex (ANR-11-LABX-0060) and the A*MIDEX project (ANR-11-IDEX-0001-02) funded by the 'Investissements d'Avenir' French government program. IRiS and T120 thank all the Observatoire de Haute-Provence staff for the permanent support. SB, NK, RN, and MV acknowledge the Shota Rustaveli National Science Foundation (SRNSF grant No 218070). TAROT has been built with the support of the Institut National des Sciences de l'Univers, CNRS,France. TAROT is funded by theCNESand thanks the help of the technical staff of the Observatoire de Haute Provence, OSU-Pytheas.