Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userA citizen science exploration of the X-ray transient sky using the EXTraS science gateway
108
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Modern soft X-ray observatories can yield unique insights into time domain astrophysics, and a huge amount of information is stored - and largely unexploited - in data archives. Like a treasure-hunt, the EXTraS project harvested the hitherto unexplored temporal domain information buried in the serendipitous data collected by the European Photon Imaging Camera instrument onboard the XMM- Newton satellite in 20 years of observations. The result is a vast catalogue, describing the temporal behaviour of hundreds of thousands of X-ray sources. But the catalogue is just a starting point because it has to be, in its turn, further analysed. During the project an education activity has been defined and run in several workshops for high school students in Italy, Germany and UK. The final goal is to engage the students, and in perspective citizen scientists, to go through the whole validation process: they look into the data and try to discover new sources, or to characterize already known sources. This paper describes how the EXTraS science gateway is used to accomplish these tasks and highlights the first discovery, a flaring X-ray source in the globular cluster NGC 6540.
rate research
Read More
Temporal variability in flux and spectral shape is ubiquitous in the X-ray sky and carries crucial information about the nature and emission physics of the sources. The EPIC instrument on board the XMM-Newton observatory is the most powerful tool for studying variability even in faint sources. Each day, it collects a large amount of information about hundreds of new serendipitous sources, but the resulting huge (and growing) dataset is largely unexplored in the time domain. The project called Exploring the X-ray transient and variable sky (EXTraS) systematically extracted all temporal domain information in the XMM-Newton archive. This included a search and characterisation of variability, both periodic and aperiodic, in hundreds of thousands of sources spanning more than eight orders of magnitude in timescale and six orders of magnitude in flux, and a search for fast transients that were missed by standard image analysis. All results, products, and software tools have been released to the community in a public archive. A science gateway has also been implemented to allow users to run the EXTraS analysis remotely on recent XMM datasets. We give details on the new algorithms that were designed and implemented to perform all steps of EPIC data analysis, including data preparation, source and background modelling, generation of time series and power spectra, and search for and characterisation of different types of variabilities. We describe our results and products and give information about their basic statistical properties and advice on their usage. We also describe available online resources. The EXTraS database of results and its ancillary products is a rich resource for any kind of investigation in almost all fields of astrophysics. Algorithms and lessons learnt from our project are also a very useful reference for any current and future experiment in the time domain.
The Vanishing & Appearing Sources during a Century of Observations (VASCO) project investigates astronomical surveys spanning a 70 years time interval, searching for unusual and exotic transients. We present herein the VASCO Citizen Science Project, that uses three different approaches to the identification of unusual transients in a given set of candidates: hypothesis-driven, exploratory-driven and machine learning-driven (which is of particular benefit for SETI searches). To address the big data challenge, VASCO combines methods from the Virtual Observatory, a user-aided machine learning and visual inspection through citizen science. In this article, we demonstrate the citizen science project, the new and improved candidate selection process and give a progress report. We also present the VASCO citizen science network led by amateur astronomy associations mainly located in Algeria, Cameroon and Nigeria. At the moment of writing, the citizen science project has carefully examined 12,000 candidate image pairs in the data, and has so far identified 713 objects classified as vanished. The most interesting candidates will be followed up with optical and infrared imaging, together with the observations by the most potent radio telescopes.
The Zwicky Transient Facility (ZTF), a public-private enterprise, is a new time domain survey employing a dedicated camera on the Palomar 48-inch Schmidt telescope with a 47 deg$^2$ field of view and 8 second readout time. It is well positioned in the development of time domain astronomy, offering operations at 10% of the scale and style of the Large Synoptic Survey Telescope (LSST) with a single 1-m class survey telescope. The public surveys will cover the observable northern sky every three nights in g and r filters and the visible Galactic plane every night in g and r. Alerts generated by these surveys are sent in real time to brokers. A consortium of universities which provided funding (partnership) are undertaking several boutique surveys. The combination of these surveys producing one million alerts per night allows for exploration of transient and variable astrophysical phenomena brighter than r $sim$ 20.5 on timescales of minutes to years. We describe the primary science objectives driving ZTF including the physics of supernovae and relativistic explosions, multi-messenger astrophysics, supernova cosmology, active galactic nuclei and tidal disruption events, stellar variability, and Solar System objects.
The MAXI (Monitor of All-sky X-ray Image) mission is the first astronomical payload to be installed on the Japanese Experiment Module-Exposed Facility (JEM-EF) on the ISS. It is scheduled for launch in the middle of 2009 to monitor all-sky X-ray objects on every ISS orbit. MAXI will be more powerful than any previous X-ray All Sky Monitor (ASM) payloads, being able to monitor hundreds of AGN. MAXI will provide all sky images of X-ray sources of about 20 mCrab in the energy band of 2-30 keV from observation on one ISS orbit (90 min), about 4.5 mCrab for one day, and about 1 mCrab for one month. A final detectability of MAXI could be 0.2 mCrab for 2 year observations.
We investigate the development of scientific content knowledge of volunteers participating in online citizen science projects in the Zooniverse (www.zooniverse.org), including the astronomy projects Galaxy Zoo (www.galaxyzoo.org) and Planet Hunters (www.planethunters.org). We use econometric methods to test how measures of project participation relate to success in a science quiz, controlling for factors known to correlate with scientific knowledge. Citizen scientists believe they are learning about both the content and processes of science through their participation. Wont dont directly test the latter, but we find evidence to support the former - that more actively engaged participants perform better in a project-specific science knowledge quiz, even after controlling for their general science knowledge. We interpret this as evidence of learning of science content inspired by participation in online citizen science.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
