Search Publications
GRO J1744-28: an intermediate B-field pulsar in a low-mass X-ray binary
Sanna, A.; Robba, N. R.; Dauser, T. +10 more
The bursting pulsar, GRO J1744-28, went again in outburst after ∼18 yr of quiescence in 2014 mid-January. We studied the broad-band, persistent, X-ray spectrum using X-ray data from a XMM-Newton observation, performed almost at the peak of the outburst, and from a close INTEGRAL observation, performed 3 d later, thus covering the 1.3-70.0 keV band…
Investigating powerful jets in radio-loud narrow-line Seyfert 1s
Larsson, J.; Giroletti, M.; Dallacasa, D. +5 more
We report results on multiband observations from radio to γ-rays of the two radio-loud narrow-line Seyfert 1 (NLSy1) galaxies PKS 2004-447 and J1548+3511. Both sources show a core-jet structure on parsec scale, while they are unresolved at the arcsecond scale. The high core dominance and the high variability brightness temperature make these NLSy1…
Study of the reflection spectrum of the accreting neutron star GX 3+1 using XMM-Newton and INTEGRAL
Sanna, A.; Di Salvo, T.; Burderi, L. +6 more
Broad emission features of abundant chemical elements, such as iron, are commonly seen in the X-ray spectra of accreting compact objects and their studies can provide useful information about the geometry of the accretion processes. In this work, we focus our attention on GX 3+1, a bright, persistent accreting low-mass X-ray binary, classified as …
What powers the 3000-day light curve of SN 2006gy?
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Cenko, S. Bradley +11 more
SN 2006gy was the most luminous supernova (SN) ever observed at the time of its discovery and the first of the newly defined class of superluminous supernovae (SLSNe). The extraordinary energetics of SN 2006gy and all SLSNe (>1051 erg) require either atypically large explosion energies (e.g. pair-instability explosion) or the efficie…
Optical confirmation and redshift estimation of the Planck cluster candidates overlapping the Pan-STARRS Survey
Price, P. A.; Desai, S.; Chambers, K. C. +16 more
We report results of a study of Planck Sunyaev-Zel'dovich effect selected galaxy cluster candidates using the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) imaging data. We first examine 150 Planck-confirmed galaxy clusters with spectroscopic redshifts to test our algorithm for identifying optical counterparts and measuring t…
The stellar kinematics of corotating spiral arms in Gaia mock observations
Cropper, Mark; Grand, Robert J. J.; Minchev, Ivan +3 more
We have observed an N-body/smoothed particle hydrodynamics simulation of a Milky Way-like barred spiral galaxy. We present a simple method that samples N-body model particles into mock Gaia stellar observations and takes into account stellar populations, dust extinction and Gaia's science performance estimates. We examine the kinematics of stars w…
Globular cluster interstellar media: ionized and ejected by white dwarfs
Zijlstra, A. A.; McDonald, I.
Ultraviolet radiation from white dwarfs can efficiently clear Galactic globular clusters (GCs) of their intracluster medium (ICM). This solves the problem of the missing ICM in clusters, which is otherwise expected to build up to easily observable quantities. To show this, we recreate the ionizing flux in 47 Tuc, following randomly generated stars…
CoRoT space photometry of seven Cepheids
Poretti, E.; Rainer, M.; Baglin, A. +4 more
A few Galactic classical Cepheids were observed in the programmes of space missions as Coriolis, MOST, and Kepler. An appealing opportunity was to detect additional non-radial modes, thus opening the possibility to perform asteroseismic studies and making the pulsational content of Galactic Cepheids more similar to that of Magellanic Clouds ones. …
The first pre-supersoft X-ray binary
Bayo, A.; Gänsicke, B. T.; Pala, A. F. +8 more
We report the discovery of an extremely close white dwarf plus F dwarf main-sequence star in a 12 h binary identified by combining data from the Radial Velocity Experiment survey and the Galaxy Evolution Explorer survey. A combination of spectral energy distribution fitting and optical and Hubble Space Telescope ultraviolet spectroscopy allowed us…
Evolution of the brightest cluster galaxies: the influence of morphology, stellar mass and environment
Conselice, Christopher J.; Zhao, Dongyao; Aragón-Salamanca, Alfonso
Using a sample of 425 nearby brightest cluster galaxies (BCGs) from von der Linden et al., we study the relationship between their internal properties (stellar masses, structural parameters and morphologies) and their environment. More massive BCGs tend to inhabit denser regions and more massive clusters than lower mass BCGs. Furthermore, cDs, whi…