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WHIMs along the line of sight to Markarian 421
Tutor. Dr. Andy Pollock
In the context of the current cosmological model, recent observations show that the amount of baryons is consistent with theoretical predictions for redshifts >2. At smaller redshifts, however, the number of baryons detected is much smaller than expected. Some scientists believe these 'missing' baryons could lay undetected in the intergalactic space, forming filamental gas structures between the galaxies: the so-called WHIMs (Warm-Hot Intergalactic Medium).
Previous studies on XMM Newton and Chandra (NASA satellite) data have given birth to a great controversy between the scientists who say they have found WHIM absorption lines and those who say the lines are not there. We are going to use the data retrieved by XMM Newton from Markarian 421, a very bright and close (z=0.03) blazar that emits a continuum source of light, and we will search for absorption lines in this spectrum. Since the source emits a continuum spectrum, any absorption lines we find must come from the matter between us and Mrk 421, either local matter (no redshift on the absorption lines) or WHIMs (redshifted lines). Our purpose is to contribute to solve the controversy about the existence of the WHIM.
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Beatriz Mingo
Universidad Autónoma de Madrid
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Universidad Complutense de Madrid
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XMM-Newton Cross-Calibration
Tutor. Dr. M.G.F Kirsch & Dr. Martin Stuhlinger
The goal of this project is a check of the calibration of the x-ray instruments pn, MOS and RGS on board the XMM-Newton satellite. In order to do this certain calibration relevant targets are chosen and processed with the XMM-SAS. The main aim of the project is to define optimum extraction regions avoiding pile-up in order to produce reliable source and background spectra in combination with correlated response matrices.
Fitting models to those spectra using XSPEC and determining the flux in various energy bands will allow to provide some insight into the cross calibration situation of the above mentioned instruments. Our work aims to increase the number of targets that can be automatically processed in
the XMM-Newton calibration archive such that the calibration evaluation will be based on a bigger
statistical sample.
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Using likelihood statistics as goodness-of-fit measures in X-ray astronomy
Tutor. Dr. Andy Pollock
We want to know the Goodness of fit measures in X-ray astronomy using Poisson statitics processes -which can model a sequence of photons arriving at random times- then, Goodness-of-fit tests can at best tell us whether one distribution is or is not the same as the other, and they say even that only with some probability. Finaly, parameter estimates is derived minimising chi-squared or maximising likelihood statistics.
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Alicia Martínez
Universidad Complutense de Madrid
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Pablo Marcos
Universidad Complutense de Madrid
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XMM-Newton Cross-Calibration
Tutor. Dr. M.G.F Kirsch & Dr. Martin Stuhlinger
The goal of this project is a check of the calibration of the x-ray instruments pn, MOS and RGS on board the XMM-Newton satellite. In order to do this certain calibration relevant targets are chosen and processed with the XMM-SAS. The main aim of the project is to define optimum extraction regions avoiding pile-up in order to produce reliable source and background spectra in combination with correlated response matrices.
Fitting models to those spectra using XSPEC and determining the flux in various energy bands will allow to provide some insight into the cross calibration situation of the above mentioned instruments. Our work aims to increase the number of targets that can be automatically processed in
the XMM-Newton calibration archive such that the calibration evaluation will be based on a bigger
statistical sample.
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Model PSF effects of pile-up on 3D
Tutor. Dr. Martin Stuhlinger
Severe pile-up can significantly affect the shape of the PSF (point spread function). In case of many photons arriving in neighboring pixels within a readout frame the on-board software cannot distinguish individual photons. In this case single events are summarized as multiple events so the pattern distribution changes and thus the number of photons at the center of the PSF decreases. This change can be used to estimate the amount of pile-up. The goal of the project is to study the shape of the PSF using the observation data and its change with pile-up. Finally a 3D model of the PSF will be created.
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Jonathan Gimeno
Universidad Complutense de Madrid |
Pablo Cassatella
Università degli Studi Roma Tre |
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General relativistic effects through X-ray spectroscopy of Active Galactic Nuclei: the case of 1ES1615+061
Tutor. Dr. Matteo Guainazzi
During his stage at ESAC, Pablo Cassatella will carry out the full timing and spectral analysis of several XMM-Newton observations of the Seyfert 1 galaxy 1ES1615+061. The main goal of this study is the physical characterization of the high-energy emission in this object, for which claims of an extreme variability of an intervening ionized absorber have been discussed in the literature on the basis of moderate-quality spectra obtained prior to the launch of XMM-Newton. This study will allow Pablo to clarify the location and possible distribution of AGN-influenced gas in the nuclear surroundings, as well as the origin of other reprocessing features - K-alpha fluorescence iron line,
Compton-reflection - imprinting the X-ray spectrum.
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Search for thermonuclear X-ray bursts in neutron star
Tutor. Dr. Celia Sanchez & Dr. Erik Kuulkers
The project aims to investigate variable X-ray sources found in the Integral Galactic Bulge Monitoring Program of the Integral Satellite.More precisely we want to investigate the variability of these sources in different timescales, using the data of the ISGRI detector onboard the Satellite. We want to look as well for X-ray bursters (known or unknown) using this data.This task has been already achieved for JEMX data and shall now be extended to the ISGRI data. ISGRI, which is a detector of the IBIS camera, has a wider field of view and works in a higher energy range then the JEMX detector. The work is the merger of the projects Integral-1 and Integral-2.
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Martin Willitsch
Technische Universität Wien
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Celia Perez
Universidad Complutense de Madrid
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A study of gamma-ray selected AGN with INTEGRAL
Tutor. Dr. Rees Williams
My project consists in an alalysis of gamma-ray in selected Active Galaxies Nuclei with INTEGRAL data from MeV selected blazars. To avoid the project becomes a project with mainly upper limits we have included the source PG 1416-129 wich is the highest luminosity radio quiet quasar listed in the first INTEGRAL AGN catalogue.
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Security Scripts for the Computer Support Group
Tutor. Ruben Alvarez
Due to the increasing number of servers in the Science DMZ, for both security and system administration reasons, there is the need to consolidate the logs from those servers and in some cases the applications that run inside them onto a central Log Server. That Log Server will be built using already existing hardware and free tools.
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Adolfo Vazquez
Universidad Complutense de Madrid
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Jose Vicente Hernandez
Universidad Autonoma de Barcelona
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VO compliance of the Open Cluster Database
Tutor. Dr. David Barroso
This project has the philosophy that has been used in the Spanish Virtual Observatory. A tool that permits to integrate information(astronomical archives) of different data bases, in a main data base. One of the main goals is to maximize the accessibility to the information for any person, and to obtain an efficient information processing. The platform independence and the minimization of the software requirements are also desirable. The project is based in a web application using the http protocol. We will use the Internet technologies, like Java, JSP, SQL, PL/SQL. The only requirements with the end user are an internet connection and a web browser.
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Studying the stellar wind in the Vela X-1 system with XMM RGS
Tutor. Dr. Andy Pollock
Vela X-1 is the archetypical neutron star high-mass X-ray binary. A neutron star orbits a supergiant star and sweeps up part of the strong stellar wind. This accretion releases much gravitational energy in the form of X-rays. In this project, a spectroscopic analysis of an observation of Vela X-1 with XMM's reflection grating spectrometer (and other archived observations) will be performed to study the emission lines from the circumstellar wind material. The geometry of the accretion flow and the dynamics of the wind is still unknown; recent simulations show a highly complex behaviour due to the interaction of the photoionizing radiation from the neutron star and the photoabsorption-driven wind that powers the accretion,
and all that within the rotating binary system.
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Manfred Hanke
Universität Erlangen-Nuremberg |
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Harsit Patel
University of Leicester
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XMM-Newton Cross-calibration: Archive data processing
Tutor. Dr. M.G.F Kirsch & Dr. Martin Stuhlinger
The aim of this project is to check calibration for the instruments MOS1, MOS2, pn , RGS1 and RGS2 on board the satellite XMM-Newton. We carry out the calibration on relevant targets contained in the cross calibration archive by processing them with a data reduction package. The goals of my project are to test and extend the current data reduction package – XARV - and to include extended sources i.e./ Galaxy clusters, SNR in the calibration archive. Our work will increase the number of objects in the calibration archive so that the calibration of the above instruments is based on bigger statistical sample.
The calibration process involves defining optimum extraction regions avoiding pile-up in order to produce reliable source and background spectra in combination with correlated response matrices. We fit models to these spectra using XSPEC and determine the flux in various energy bands to provide an insight in to the calibration situation of the aforementioned instruments.
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On the Improvement of the Reddening Correction from Ultraviolet Spectra
Tutor. Dr. Carmen Morales & Dr. Angelo Cassatella
The interstellar dust hump localized at 2200 Å, presumably due to absorption by vibrational states of graphites and PAH nano-sized grains, is the strongest extinction feature and one of the most accurate tools to determine the reddening correction of stellar spectra. Its shape is highly dependant on the enviroment that produces it: density, grain size, total to selective extinction , etc. The best accuracy achieved in the colour excess E(B-V) is about ±0.05 dex, which still involves some flux uncertainties in the optical but very large in the ultraviolet. Our aim is to develop a new method to halve this accuracy, reducing the uncertainty from about 51% to about 18% at 1300 Å. We will study in a large sample of INES sources with low and high reddening: i) The correlation between E(B-V) and the parameters of shape of the 2200 Å hump: equivalent width, depth and area. ii) The adjustment of the spectra as a function of E(B-V) to a Kurucz model atmosphere in the Spectral Type, Metallicity and Gravity space.
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Illeana Gomez
Universidad Autonoma de Madrid
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Olof Tengstrand
Institute of Technology, Linköping
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GPS-project
Tutor. Dr. Matteo Guainazzi
The project consists of a X-ray study of a complete sample of GPS galaxies. These are galaxies with strong and small jets which are believed to represent the inital phase of giant jets that are often observed in the far universe. The goal is to analyze 5-7 recently taken observations of XMM-Newton data in order to calculate physical properties near to the cores which will be important in the trial to forsee the evolution of these jets and to create a link between small- and largescale radio structures.
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XMM-Newton Cross-Calibration
Tutor. Dr M.G.F Kirsch & Dr. Martin Stuhlinger
One of the main instruments onboard XMM-Newton is the European Photon Imaging Camera (EPIC). EPIC consists of two MOS and one pn-CCD camera. Both camera systems operate in the energy range from 0.2-15 keV and provide spatial, energy and timing information for the detected X-ray photons.
The EPIC MOS cameras can be operated in a special mode with very high time resolution. This mode has never been fully calibrated. We aim to assess the calibration of flux, energy and timing by a systematical analysis of a subset of all calibration observations. Chi-squared fit techniques will be used to evaluate the results of spectral fits on the basis of the in X-ray astronomical data analysis well established forward folding approach. For the timing calibration a special observation of the Crab nebula will be analysed using epoch folding techniques in order to determine the relative and absolute timing. In case of calibration deficits corrections will be developed and their implementation into software and calibration files will be tested.
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John-Olov Larsson
Institute of Technology, Linköping
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Ana Gonzalez
Universidad Complutense de Madrid
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Monitoring X-ray pulsars with INTEGRAL in the Galactic Bulge
Tutor. Dr. Erik Kuulkers & Dr. Peter Kretschmar
The central region of our Galaxy (=Galactic Bulge) is being watched regularly every couple of days with short observations at X-ray and gamma-ray wavelengths with INTEGRAL. While a quick analysis is being done in near-real time, more detailed analysis for most sources needs to
be done. The proposed project is to extract light curves and spectra of the several X-ray pulsars present in the Galactic Bulge running standard tools and to analyze them in a straightforward manner. The aim is to characterize the pulse history of selected sources and their spectral evolution as a function of pulse phase. We expect to arrive at published results from this project.
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Study of the X-ray components in a nearby active galaxy
Tutor: Dr. Nora Loiseau
The project consisted in extracting from the XSA archive X-ray data of the nearby barred spiral galaxy NGC 6221, observed serendipitously by XMM-Newton. This galaxy seems to be classified differently at different wavelengths. Depending if we analyse the optical (+IR) spectrum or the emission in the X-ray range, we can observe quite different characteristics of NGC 6221. From observations at optical wavelengths, this galaxy was classified as a Seyfert 2 with a strong *starburst *component; however, if we observe it at X-rays wavelengths, the contribution of the AGN itself seems to be more significant. The data were quite complicated to analyse because the galaxy was away from the centre of the field of view, in a region where the PSF is bigger and not circular. Anyway we could analyse the data of two observations taken in different dates and we could fit well the spectrum for the 3 EPIC cameras, and notice the variability of the nucleus.
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Beatriz Vega
Universidad Complutense de Madrid |
