Search Publications
IGR J14488-4008: an X-ray peculiar giant radio galaxy discovered by INTEGRAL
Venturi, T.; Dallacasa, D.; Bird, A. J. +5 more
In this paper, we report the discovery and detailed radio/X-ray analysis of a peculiar giant radio galaxy (GRG) detected by INTEGRAL, IGR J14488-4008. The source has been recently classified as a Seyfert 1.2 galaxy at redshift 0.123; the radio data denote the source to be a type II Fanaroff-Riley radio galaxy, with a linear projected size exceedin…
Morpho-kinematics of the planetary nebula NGC 3242: an analysis beyond its multiple-shell structure
Gómez-Muñoz, M. A.; Vázquez, R.; Ayala, S. +3 more
In this paper we present the results of optical high-resolution imaging and spectroscopy of the complex planetary nebula (PN) NGC 3242. Our study is based on the analysis of the narrow-band Hα λ6563, [O III] λ5007, [N II] λ6584, and [S II] λ6724 Å images, and high-resolution spectroscopy using spectral ranges centred on the Hα λ6564, [N II] λ6583,…
Linearized iterative least-squares (LIL): a parameter-fitting algorithm for component separation in multifrequency cosmic microwave background experiments such as Planck
Khatri, Rishi
We present an efficient algorithm for least-squares parameter fitting, optimized for component separation in multifrequency cosmic microwave background (CMB) experiments. We sidestep some of the problems associated with non-linear optimization by taking advantage of the quasi-linear nature of the foreground model. We demonstrate our algorithm, lin…
X-ray emission from charge exchange in the Cygnus Loop SNR
Wang, Q. Daniel; Roberts, Shawn R.
The Cygnus Loop has been the focus of substantial debate concerning the contribution of charge exchange (CX) to supernova remnant (SNR) X-ray emission. We take advantage of a distinct feature of CX, enhanced Kα forbidden line emission, and employ the energy centroid of the O VII Kα triplet as a diagnostic. Based on X-ray spectra extracted from an …
Constraining the parameters of the pulsar wind nebula DA 495 and its pulsar with Chandra and XMM-Newton
Zyuzin, D.; Danilenko, A.; Shibanov, Yu. +1 more
We present spectral and timing analyses of the X-ray emission from the pulsar wind nebula DA 495 and its central object, J1952.2+2925, suggested to be the pulsar, using archival Chandra and XMM-Newton data. J1952.2+2925 has a pure thermal spectrum which is equally well fitted either by the blackbody model with a temperature of ≈215 eV and an emitt…
36 new, high-probability, damped Lyα absorbers at redshift 0.42 < z < 0.70
Turnshek, David A.; Rao, Sandhya M.; Monier, Eric M. +3 more
Quasar damped Lyα (DLA) absorption-line systems with redshifts z < 1.65 are used to trace neutral gas over approximately 70 per cent of the most recent history of the Universe. However, such systems fall in the UV and are rarely found in blind UV spectroscopic surveys. Therefore, it has been difficult to compile a moderate-sized sample of UV DL…
Constraints on Ωm and σ8 from the potential-based cluster temperature function
Bartelmann, Matthias; Angrick, Christian; Pace, Francesco +1 more
The abundance of galaxy clusters is in principle a powerful tool to constrain cosmological parameters, especially Ωm and σ8, due to the exponential dependence in the high-mass regime. While the best observables are the X-ray temperature and luminosity, the abundance of galaxy clusters, however, is conventionally predicted as …
Suzaku observation of supernova remnant G332.5-5.6
Zhu, H.; Tian, W. W.; Wu, D.
We analyse the Suzaku X-ray Imaging Spectrometer data of the central region of supernova remnant G332.5-5.6. The X-ray data are well described by a single non-equilibrium ionization thermal model, <monospace>vnei</monospace>, with an absorbing hydrogen column density of 1.4^{+0.4}_{-0.1} × 1021 cm-2. The plasma is…
Evolutionary status of the active star PZ Mon
Semenko, E. A.; Bondar', N. I.; Gorynya, N. A. +2 more
We use original spectra and available photometric data to recover the parameters of the stellar atmosphere of PZ Mon, formerly referred to as an active red dwarf. The derived effective temperature Teff = 4700 K and gravity log g = 2.8 suggest that PZ Mon is a K2III giant. Stellar atmosphere parameters (Teff and log g), along …
Sulphur-bearing species in molecular clouds
Bilalbegović, G.; Baranović, G.
We study several molecules that could help in the solution of the missing sulphur problem in dense clouds and circumstellar regions, as well as in the clarification of the sulphur chemistry in comets. These sulphur molecules are the trimer (CH2S)3 and the tetramer (CH2S)4 of thioformaldehyde, pentathian …