Search Publications
Unresolved X-ray emission in M31 and constraints on progenitors of classical novae
Bogdán, Á.; Gilfanov, M.
We investigate unresolved X-ray emission from M31 based on an extensive set of archival XMM-Newton and Chandra data. We show that extended emission, found previously in the bulge and thought to be associated with a large number of faint compact sources, extends to the disc of the galaxy with similar X-ray to K-band luminosity ratio. We also detect…
A multiwavelength view of the protostellar binary IRAS 04325+2402: a case for turbulent fragmentation
Scholz, A.; Saviane, I.; Jayawardhana, R. +6 more
IRAS 04325+2402 (hereinafter IRAS 04325) is a complex protostellar system hosting two young stellar objects (AB and C) at a separation of 1250 au. Here, we present a new deep Gemini imaging and spectroscopy for the system covering the wavelength regime from 1 to 12 µm as well as Submillimeter Array interferometry at 870 µm, in combinat…
The Algol binary system KZ Pavonis revisited
Erdem, A.; Budding, E.; Sürgit, D.
We present results from analysing new spectroscopic and photometric observations of the KZ Pav (IDS 20490-7048 A-BC) multiple system. High-resolution spectra were taken at the Mt John University Observatory in 2007 and 2008. Radial velocities for the close binary were determined from cross-correlation and spectral disentangling methods. The result…
Quantitative measure of evolution of bright cluster galaxies at moderate redshifts
Kembhavi, Ajit K.; Wadadekar, Yogesh; Vikram, Vinu +1 more
Using archival data from the Hubble Space Telescope, we study the quantitative morphological evolution of spectroscopically confirmed bright galaxies in the core regions of nine clusters ranging in redshift from z = 0.31 to 0.84. We use morphological parameters derived from two-dimensional bulge-disc decomposition to study the evolution. We find a…
Root mean square variability properties of iron lines in Seyferts
Nandra, Kirpal; Bhayani, Shyam
We present an analysis of the rms variability spectra of a sample of 18 observations of 14 Seyfert galaxies observed by XMM-Newton, which exhibit sufficient variability and signal-to-noise ratio to examine the variations in the iron K band. The narrow core of the Kα line at 6.4keV, seen universally in Seyferts, shows minimal evidence for variabili…
Be/X-ray binary SXP6.85 undergoes large Type II outburst in the Small Magellanic Cloud
Haberl, F.; Udalski, A.; Coe, M. J. +6 more
The Small Magellanic Cloud (SMC) Be/X-ray binary pulsar SXP6.85 = XTE J0103-728 underwent a large Type II outburst beginning on 2008 August 10. The source was consistently seen for the following 20 weeks (MJD = 54688-54830). We present X-ray timing and spectroscopic analysis of the source as a part of our ongoing Rossi X-ray Timing Explorer (RXTE)…
The z = 0.0777 CIII absorber towards PHL 1811 as a case study of a low-redshift weak metal line absorber
Charlton, J. C.; Lacki, B. C.
We consider the physical conditions and origin of the z = 0.0777 absorption system observed in CIII, CII, SiIII, CIV, OVI and HI absorption along the line of sight towards the quasar PHL 1811. We analysed the Hubble Space Telescope/Space Telescope Imaging Spectrograph and Far Ultraviolet Spectroscopic Explorer spectra of this quasar and compared t…
An X-ray bright nucleus in the low-surface-brightness galaxy UGC 6614
Naik, Sachindra; Das, M.; Jain, C. +1 more
We report a study of the X-ray emission from the nuclear region of the low-surface-brightness (LSB) galaxy UGC 6614. Very little is known about the central objects in LSB galaxies, especially their X-ray properties and X-ray spectra. In this study we have used XMM-Newton archival data to study the characteristics of the X-ray spectrum and the X-ra…
High-velocity-resolution observations of OH main line masers in the M82 starburst
Muxlow, T. W. B.; Argo, M. K.; Beswick, R. J. +2 more
Using the Very Large Array, a series of high-velocity-resolution observations have been made of the M82 starburst at 1.6GHz. These observations follow up on previous studies of the main line OH maser emission in the central kiloparsec of this starburst region, but with far greater velocity resolution, showing significant velocity structure in some…
Chemical and radiative transfer modelling of the ISO-LWS Fabry-Perot spectra of Orion-KL water lines
Barlow, M. J.; Swinyard, B. M.; Viti, S. +2 more
We present chemical and radiative transfer models for the many far-infrared ortho- and para-H2O lines that were observed from the Orion-KL region in high resolution Fabry-Pérot (FP) mode by the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). The chemistry of the region was first studied by simulating th…