Search Publications
HST optical polarimetry of the Vela pulsar and nebula
Mignani, R. P.; Moran, P.; Shearer, A.
Polarization measurements of pulsars offer a unique insight into the geometry of the emission regions in the neutron star magnetosphere. Therefore, they provide observational constraints on the different models proposed for the pulsar emission mechanisms. Optical polarization data of the Vela pulsar was obtained from the Hubble Space Telescope (HS…
Resolving different sources of fast X-ray variability of the dwarf nova RU Peg in quiescence
Ness, J. -U.; Dobrotka, A.; Mineshige, S.
We analysed an X-ray light curve of the dwarf nova RU Peg taken by XMM-Newton with a duration of 46300 s. The power density spectrum has a complicated shape with two red noise and two white noise components, indicating the presence of two turbulent regions. We developed a statistical `toy model' to study light curves with variability produced by a…
The evolution of star formation activity in galaxy groups
Finoguenov, A.; Berta, S.; Magnelli, B. +30 more
We study the evolution of the total star formation (SF) activity, total stellar mass (ΣM*) and halo occupation distribution (HOD) in massive haloes by using one of the largest X-ray selected sample of galaxy groups with secure spectroscopic identification in the major blank field surveys (ECDFS, CDFN, COSMOS, AEGIS). We provide an accur…
Globular clusters: DNA of early-type galaxies?
Forte, Juan C.; Vega, E. Irene; Escudero, Carlos +4 more
This paper explores if the mean properties of early-type galaxies (ETGs) can be reconstructed from `genetic' information stored in their globular clusters (GCs; i.e. in their chemical abundances, spatial distributions and ages). This approach implies that the formation of each globular occurs in very massive stellar environments, as suggested by s…
A radio characterization of Galactic compact bubbles
Paladini, R.; Umana, G.; Agliozzo, C. +6 more
We report the radio observations of a subsample of the 428 Galactic compact bubbles discovered at 24 µm with the MIPSGAL survey. Pervasive through the entire Galactic plane, these objects are thought to be different kinds of evolved stars. The very large majority of the bubbles (∼70 per cent) are however not yet classified. We conducted radi…
Hα photometry of low-mass stars in 47 Tucanae: chromospheric activity and exotica
Panagia, N.; Pasquini, L.; Beccari, G. +1 more
We have used archival Hubble Space Telescope observations obtained with the Advanced Camera for Surveys to study the Hα emission properties of main-sequence stars in the globular cluster 47 Tucanae. Using a combination of multiband observations in the F606W, F814W and F658N bands, we search for stars showing Hα excess emission. An accurate photome…
CoRoT-22 b: a validated 4.9 R⊕ exoplanet in 10-d orbit
Mazeh, T.; Aigrain, S.; Alonso, R. +37 more
The CoRoT satellite has provided high-precision photometric light curves for more than 163 000 stars and found several hundreds of transiting systems compatible with a planetary scenario. If ground-based velocimetric observations are the best way to identify the actual planets among many possible configurations of eclipsing binary systems, recent …
Disentangling a group of lensed submm galaxies at z∼ 2.9
Ivison, R. J.; Richard, Johan; Smail, Ian +17 more
MS 0451.6-0305 is a rich galaxy cluster whose strong lensing is particularly prominent at submm wavelengths. We combine new Submillimetre Common-User Bolometer Array (SCUBA)-2 data with imaging from Herschel Spectral and Photometric Imaging Receiver (SPIRE) and PACS and Hubble Space Telescope in order to try to understand the nature of the sources…
TYC 3159-6-1: a runaway blue supergiant
Miroshnichenko, A. S.; Gvaramadze, V. V.; Zharikov, S. V. +2 more
We report the results of optical spectroscopy of a candidate evolved massive star in the Cygnus-X region, TYC 3159-6-1, revealed via detection of its curious circumstellar nebula in archival data of the Spitzer Space Telescope. We classify TYC 3159-6-1 as an O9.5-O9.7 Ib star and derive its fundamental parameters by using the stellar atmosphere co…
Higher prevalence of X-ray selected AGN in intermediate-age galaxies up to z ∼ 1
Barro, Guillermo; Pérez-González, Pablo G.; Nandra, Kirpal +9 more
We analyse the stellar populations in the host galaxies of 53 X-ray selected optically dull active galactic nuclei (AGN) at 0.34 < z < 1.07 with ultradeep (mAB = 26.5, 3σ) optical medium-band (R ∼ 50) photometry from the Survey for High-z Absorption Red and Dead Sources (SHARDS). The spectral resolution of SHARDS allows us to cons…