Search Publications
Herschel-PACS measurements of nitrogen enrichment in nebulae around Wolf-Rayet stars
Barlow, M. J.; Stock, D. J.
For three nebulae that have early-WN Wolf-Rayet exciting stars, NGC 6888, WR 8 and Abell 48, we have obtained Herschel-PACS line scans of the [N III] 57-µm and [O III] 88-µm lines, along with the 122- and 205-µm lines of [N II]. From the former two lines we have derived N2+/O2+ abundance ratios, equal to the…
Discovery of X-ray pulsations in the Be/X-ray binary IGR J21343+4738
Zezas, A.; Reig, P.
We report on the discovery of X-ray pulsations in the Be/X-ray binary IGR J21343+4738 during an XMM-Newton observation. We obtained a barycentric corrected pulse period of 320.35 ± 0.06 s. The pulse profile displays a peak at low energy that flattens at high energy. The pulse fraction is 45 ± 3 per cent and independent of energy within the statist…
OMC/INTEGRAL photometric observations of pulsating components in eclipsing binaries and characterization of DY Aqr
Montesinos, B.; Mas-Hesse, J. M.; Martín-Ruiz, S. +2 more
We present the search for eclipsing binaries with a pulsating component in the first catalogue of optically variable sources observed by Optical Monitoring Camera (OMC)/INTEGRAL, which contains photometric data for more than 1000 eclipsing binaries. Five objects were found and a detailed analysis of one of them, DY Aqr, has been performed. Photome…
Probing mass segregation in the globular cluster NGC 6397
Kepler, S. O.; Costa, J. E. S.; Bonatto, C. +3 more
In this study, we present a detailed study of mass segregation in the globular cluster NGC 6397. First, we carry out a photometric analysis of projected European Southern Observatory (ESO)-Very Large Telescope (VLT) data (between 1 and 10 arcmin from the cluster centre), presenting the luminosity function corrected by completeness. The luminosity …
Detection of distinct power spectra in soft and hard X-ray bands in the hard state of GRS 1915+105
Stiele, H.; Yu, W.
The well-known black hole X-ray binary GRS 1915+105 is a unique source in the sense that it cannot be classified within the standard picture of black hole binary states. In this work, we study archival XMM-Newton observations taken between 2003 and 2004 of the χ variability class of GRS 1915+105, which corresponds to the hard state in the standard…
Evolutionary tracks of massive stars during formation
Smith, Michael D.
A model for massive stars is constructed by piecing together evolutionary algorithms for the protostellar structure, the environment, the inflow and the radiation feedback. We investigate specified accretion histories of constant, decelerating and accelerating forms and consider both hot and cold accretion, identified with spherical free-fall and …
Broad iron emission line and kilohertz quasi-periodic oscillations in the neutron star system 4U 1636-53
Hiemstra, Beike; Belloni, Tomaso; Méndez, Mariano +3 more
Both the broad iron (Fe) line and the frequency of the kilohertz quasi-periodic oscillations (kHz QPOs) in neutron star low-mass X-ray binaries (LMXBs) can potentially provide independent measures of the inner radius of the accretion disc. We use XMM-Newton and simultaneous Rossi X-ray Timing Explorer observations of the LMXB 4U 1636-53 to test th…
Herschel/PACS observations of the host galaxy of GRB 031203.
Page, M. J.; Symeonidis, M.; Schady, P. +6 more
We present Herschel/PACS observations of the nearby (z = 0.1055) dwarf galaxy that has hosted the long gamma-ray burst (LGRB) 031203. Using the PACS data, we have been able to place constraints on the dust temperature, dust mass, total infrared (IR) luminosity and IR-derived star formation rate (SFR) for this object. We find that the GRB host gala…
The innermost globular clusters of M87
Prieto, M. A.; Acosta-Pulido, J. A.; Fernández-Ontiveros, J. A. +1 more
We present a comprehensive multiwavelength photometric analysis of the innermost (∼3 × 3 kpc2) 110 globular clusters (GCs) of M87. Their spectral energy distributions (SEDs) were built taking advantage of new ground-based high-resolution near-infrared imaging aided by adaptive optics at the Very Large Telescope combined with Hubble Spac…
Clustering tomography: measuring cosmological distances through angular clustering in thin redshift shells
Baugh, Carlton M.; Sánchez, Ariel G.; Salazar-Albornoz, Salvador +1 more
We test the cosmological implications of studying galaxy clustering using a tomographic approach, by computing the galaxy two-point angular correlation function ω(θ) in thin redshift shells using a spectroscopic redshift galaxy survey. The advantages of this procedure are that it is not necessary to assume a fiducial cosmology in order to convert …