Search Publications
Further Sunyaev-Zel'dovich observations of two Planck ERCSC clusters with the Arcminute Microkelvin Imager
AMI Consortium; Olamaie, Malak; Davies, Matthew L. +16 more
We present follow-up observations of two galaxy clusters detected blindly via the Sunyaev-Zel'dovich (SZ) effect and released in the Planck Early Release Compact Source Catalogue. We use the Arcminute Microkelvin Imager, a dual-array 14-18 GHz radio interferometer. After radio source subtraction, we find a SZ decrement of integrated flux density -…
Puzzling thermonuclear burst behaviour from the transient low-mass X-ray binary IGR J17473-2721
Costa, E.; Altamirano, D.; Degenaar, N. +8 more
We investigate the thermonuclear bursting behaviour of IGR J17473-2721, an X-ray transient that in 2008 underwent a 6-month long outburst, starting (unusually) with an X-ray burst. We detected a total of 57 thermonuclear bursts throughout the outburst with AGILE, Swift, Rossi X-ray Timing Explorer (RXTE) and the INTErnational Gamma-Ray Astrophysic…
Very Large Telescope Interferometer observations of the dust geometry around R Coronae Borealis stars
Gallagher, J. S.; Chesneau, O.; De Marco, O. +4 more
We are investigating the formation and evolution of dust around the hydrogen-deficient supergiants known as R Coronae Borealis (RCB) stars. We aim to determine the connection between the probable merger past of these stars and their current dust-production activities.
We carried out high angular resolution interferometric observations of thre…A strongly star-forming group: three massive galaxies associated with a quasi-stellar object
Ivison, R. J.; Ebrero, J.; Page, M. J. +4 more
We present here photometric redshift confirmation of the presence of large-scale structure around the z= 1.82 quasi-stellar object (QSO) RX J0941, which shows an overdensity of submillimetre (submm) sources. Radio imaging confirms the presence of the submm sources and pinpoints their likely optical near-infrared (NIR) counterparts. Four of the fiv…
3C 390.3: more stable evidence that the double-peaked broad Balmer lines originate from an accretion disc near a central black hole
Zhang, Xue-Guang
In this paper, we study the structure of the broad emission-line regions (BLRs) of the well-known double-peaked emitter (an active galactic nucleus with broad double-peaked low-ionization emission lines) 3C 390.3. Besides the best-fitting results for the double-peaked broad optical Balmer lines of 3C 390.3 obtained from the theoretical disc model,…
The relationship between [O III]λ5007 Å equivalent width and obscuration in active galactic nuclei
Caccianiga, A.; Severgnini, P.
In this paper we study the relationship between the equivalent width (EW) of the [O III]λ5007 Å narrow emission line in active galactic nuclei (AGN) and the level of obscuration. To this end, we combine the results of a systematic spectral analysis, both in the optical and in the X-rays, on a statistically complete sample of ∼170 X-ray selected AG…
Chandra and XMM-Newton view of the warm absorbing gas in Mrk 290
Zhang, S. N.; Longinotti, A. L.; Marshall, H. L. +3 more
We present a detailed analysis of the Chandra High Energy Transmission Grating Spectrometer (HETGS) and XMM-Newton high-resolution spectra of the bright Seyfert 1 galaxy, Mrk 290.
The Chandra HETGS spectra reveal complex absorption features that can be best described by a combination of three ionized absorbers. The outflow velocities of these…Early-type stars observed in the ESO UVES Paranal Observatory Project - III. Sub-parsec and au-scale structure in the interstellar medium*
Fossati, L.; Keenan, F. P.; Smoker, J. V. +5 more
UVES interstellar observations from the Paranal Observatory Project are presented for early-type stars located in the line of sight to the nearby open clusters IC 2391 (Omni Vel) and NGC 6475 (M7), with spectroscopic resolution R∼ 80 000 and signal-to-noise ratios in the Ti ii (3383 Å), Ca ii K, CH+ (4232 Å), Na i D and K i (7698 Å) lin…
Distance and temperature from absolute light curves of three eclipsing binaries
Wilson, R. E.; Raichur, H.
Although solutions of arbitrarily scaled eclipsing binary (EB) light curves yield the temperature of only one component (given the other temperature), absolute light curves in two or more bands can directly give temperatures of both stars if combined with radial velocity data and matched to an absolute flux model. Accurate band-to-band flux calibr…
Pulsations in the atmosphere of the rapidly oscillating star 33 Lib
Shulyak, D.; Ryabchikova, T.; Hareter, M. +4 more
In 2009, the rapidly oscillating peculiar A-type (roAp) star 33 Lib was the target of an intense observing campaign, combining ground-based spectroscopy with space photometry obtained with the Microvariability and Oscillation of STars (MOST) satellite. We collected 780 spectra using the Echelle Spectro Polarimetric Device for the Observation of St…