Search Publications
Unveiling the nature of RXJ0002+6246 with XMM-Newton
Caraveo, P. A.; Tiengo, A.; de Luca, A. +3 more
The X-ray source RXJ0002+6246 was discovered close to the supernova remnant CTB1 in a ROSAT observation performed in 1992. The source phenomenology (soft spectrum, apparent lack of counterparts, possible pulsations at 242 ms, hints for surrounding diffuse emission) led to interpret it as an isolated neutron star in a new supernova remnant. We have…
The X-ray spectrum of RX J1914.4+2456 revisited
Ramsay, Gavin
It has been proposed that RX J1914.4+2456 is a stellar binary system with an orbital period of 9.5 min. As such it shares many similar properties with RX J0806.3+1527 (5.4 min). However, while the X-ray spectrum of RX J0806.3+1527 can be modelled using a simple absorbed blackbody, the X-ray spectrum of RX J1914.4+2456 has proved difficult to fit u…
The Compton-thick quasar at the heart of the high-redshift giant radio galaxy 6C0905+39
Fabian, A. C.; Erlund, M. C.; Blundell, Katherine M. +1 more
Our XMM-Newton spectrum of the giant, high-redshift (z = 1.88) radio galaxy 6C0905+39 shows that it contains one of the most powerful, high redshift, Compton-thick quasars known. Its spectrum is very hard above 2keV. The steep XMM-Newton spectrum below that energy is shown to be due to extended emission from the radio bridge using Chandra data. Th…
A multi-coloured survey of NGC 253 with XMM-Newton: testing the methods used for creating luminosity functions from low-count data
Kolb, U.; Barnard, R.; Greening, L. Shaw
NGC 253 is a local, starbursting spiral galaxy with strong X-ray emission from hot gas, as well as many point sources. We have conducted a spectral survey of the X-ray population of NGC 253 using a deep XMM-Newton observation. NGC 253 only accounts for ~20 per cent of the XMM-Newton EPIC field of view, allowing us to identify ~100 X-ray sources th…
Weak localization of electromagnetic waves and radar polarimetry of Saturn's rings
Mishchenko, Michael I.; Dlugach, Janna M.
We use a state-of-the-art physics-based model of electromagnetic scattering to analyse average circular polarization ratios measured for the A and B rings of Saturn at a wavelength of 12.6 cm. This model is directly based on the Maxwell equations and accounts for the effects of polarization, multiple scattering, weak localization of electromagneti…
Dissecting the star formation history of starburst galaxies: the case of NGC 7673
Pasquali, A.; Castangia, P.
We have collected archival data on NGC 7673 to constrain the star formation history that produced the young star clusters and the field stellar population in this galaxy during the last 2 Gyr. We have considered the sample of 50 star clusters detected by Hubble Space Telescope/WFPC2 in the UV,V and I bands and estimated their age, intrinsic redden…
A three-dimensional automated classification scheme for the TAUVEX data pipeline
Singh, Harinder P.; Murthy, Jayant; Gupta, Ranjan +3 more
In order to develop a pipeline for automated classification of stars to be observed by the Tel-Aviv University Ultra-Violet Experiment (TAUVEX) ultraviolet space telescope, we employ an artificial neural network (ANN) technique for classifying stars by using synthetic spectra in the ultraviolet (UV) region from 1250 to 3220 Å as the training set a…
Timeline analysis and wavelet multiscale analysis of the AKARI All-Sky Survey at 90µm
Goto, Tomotsugu; Nakagawa, Takao; Shirahata, Mai +17 more
We present a careful analysis of the point-source detection limit of the AKARI All-Sky Survey in the WIDE-S 90-µm band near the North Ecliptic Pole (NEP). Timeline analysis is used to detect IRAS (Infrared Astronomy Satellite) sources and then a conversion factor is derived to transform the peak timeline signal to the interpolated 90-µ…
Periodicity search for possible X-ray counterparts to radio-quiet gamma-ray pulsar candidates
Chang, Hsiang-Kuang; Lin, Lupin Chun-Che
A periodicity search of gamma-ray data is usually difficult because of the small number of detected photons. A periodicity in the timing signal at other energy bands from the counterpart to the gamma-ray source may help to establish the periodicity in the gamma-ray emission and strengthen the identification of the source in different energy bands.…
ISINA: INTEGRAL Source Identification Network Algorithm
Hill, A. B.; Bird, A. J.; Scaringi, S. +4 more
We give an overview of ISINA: INTEGRAL Source Identification Network Algorithm. This machine learning algorithm, using random forests, is applied to the IBIS/ISGRI data set in order to ease the production of unbiased future soft gamma-ray source catalogues. First, we introduce the data set and the problems encountered when dealing with images obta…