Search Publications
GS-TEC: the Gaia spectrophotometry transient events classifier
Wyrzykowski, Łukasz; Blagorodnova, Nadejda; Irwin, Mike +2 more
We present an algorithm for classifying the nearby transient objects detected by the Gaia satellite. The algorithm will use the low-resolution spectra from the blue and red spectrophotometers on board the satellite. Taking a Bayesian approach, we model the spectra using the newly constructed reference spectral library and literature-driven priors.…
Pulse phase-coherent timing and spectroscopy of CXOU J164710.2-45521 outbursts
Esposito, Paolo; Turolla, Roberto; Rea, Nanda +5 more
We present a long-term phase-coherent timing analysis and pulse-phase resolved spectroscopy for the two outbursts observed from the transient anomalous X-ray pulsar CXOU J164710.2-455216. For the first outburst we used 11 Chandra and XMM-Newton observations between 2006 September and 2009 August, the longest baseline yet for this source. We obtain…
Herschel far-IR counterparts of SDSS galaxies: analysis of commonly used star formation rate estimates
Berta, S.; Magnelli, B.; Lutz, D. +13 more
We study a hundred of galaxies from the spectroscopic Sloan Digital Sky Survey (SDSS) with individual detections in the far-infrared Herschel Photodetector Array Camera and Spectrometer bands (100 or 160 µm) and in the GALEX far-ultraviolet band up to z ∼ 0.4 in the COSMOS and Lockman Hole fields. The galaxies are divided into four spectral …
The quiescent state of the accreting X-ray pulsar SAX J2103.5+4545
Zezas, A.; Reig, P.; Doroshenko, V.
We present an X-ray timing and spectral analysis of the Be/X-ray binary SAX J2103.5+4545 at a time when the Be star's circumstellar disc had disappeared and thus the main reservoir of material available for accretion had extinguished. In this very low optical state, pulsed X-ray emission was detected at a level of LX ∼ 1033 e…
Constraining black hole masses in low-accreting active galactic nuclei using X-ray spectra
Titarchuk, L.; Gliozzi, M.; Jang, I. +1 more
In a recent work we demonstrated that a novel X-ray scaling method, originally introduced for Galactic black holes (BHs), can be reliably extended to estimate the mass of supermassive BHs accreting at a moderate to high level. Here we investigate the limits of applicability of this method to low-accreting active galactic nuclei (AGN), using a cont…
Spectral energy distributions of the BL Lac PKS 2155 - 304 from XMM-Newton
Bhagwan, Jai; Gupta, Alok C.; Papadakis, I. E. +1 more
We have used all 20 archival XMM-Newton observations of PKS 2155 - 304 with simultaneous X-ray and UV/optical data to study its long-term flux and spectral variability. We find significant variations, in all bands, on time-scales of years with an rms amplitude of ∼35-45 per cent, though the optical/UV variations are not correlated with those in th…
Masses of the components of SB2 binaries observed with Gaia - I. Selection of the sample and mass ratios of 20 new SB2s discovered with Sophie
Mazeh, T.; Tal-Or, L.; Halbwachs, J. -L. +7 more
In anticipation of the Gaia astrometric mission, a large sample of spectroscopic binaries has been observed since 2010 with the Sophie spectrograph at the Haute-Provence Observatory. Our aim is to derive the orbital elements of double-lined spectroscopic binaries (SB2s) with an accuracy sufficient finally to obtain the masses of the components wit…
The M 4 Core Project with HST - III. Search for variable stars in the primary field
van den Berg, M.; Anderson, J.; Milone, A. P. +14 more
We present the results of a photometric search for variable stars in the core of the Galactic globular cluster Messier 4 (M 4). The input data are a large and unprecedented set of deep Hubble Space Telescope WFC3 images (large programme GO-12911; 120 orbits allocated), primarily aimed at probing binaries with massive companions by detecting their …
A phenomenological model for the intracluster medium that matches X-ray and Sunyaev-Zel'dovich observations
Pfrommer, Christoph; Prada, Francisco; Zandanel, Fabio
Cosmological hydrodynamical simulations of galaxy clusters are still challenged to produce a model for the intracluster medium that matches all aspects of current X-ray and Sunyaev-Zel'dovich observations. To facilitate such comparisons with future simulations and to enable realistic cluster population studies for modelling e.g. non-thermal emissi…
The ultraviolet to far-infrared spectral energy distribution of star-forming galaxies in the redshift desert
Cepa, J.; Magdis, G.; Oteo, I. +6 more
We analyse the rest-frame ultraviolet (UV) to near-infrared (near-IR) spectral energy distribution (SED) of Lyman-break galaxies (LBGs), star-forming (SF) BzK (sBzK) and UV-selected galaxies at 1.5 ≲ z ≲ 2.5 in the COSMOS, GOODS-N and GOODS-S fields. Additionally, we complement the multiwavelength coverage of the galaxies located in the GOODS fiel…