Search Publications
IGR J14257-6117, a magnetic accreting white dwarf with a very strong strong X-ray orbital modulation
Mukai, K.; de Martino, D.; Bernardini, F. +1 more
IGR J14257-6117 is an unclassified source in the hard X-ray catalogues. Optical follow-ups suggest it could be a Cataclysmic Variable (CV) of the magnetic type. We present the first high signal-to-noise (S/N) X-ray observation performed by XMM-Newton at 0.3-10 keV, complemented with 10-80 keV coverage by Swift/BAT, aimed at revealing the source na…
Infall and outflow motions towards a sample of massive star-forming regions from the RMS survey
Cunningham, N.; Lumsden, S. L.; Moore, T. J. T. +2 more
We present the results of an outflow and infall survey towards a distance-limited sample of 31 massive star-forming regions drawn from the Red MSX source (RMS) survey. The presence of young, active outflows is identified from SiO (8-7) emission and the infall dynamics are explored using HCO+/H13CO+ (4-3) emission. …
A Gaia DR2 search for dwarf galaxies towards Fermi-LAT sources: implications for annihilating dark matter
Calore, Francesca; Ciucǎ, Ioana; Kawata, Daisuke +3 more
We make the first attempt to find dwarf galaxies in eight Fermi-LAT extended, unassociated, source fields using Gaia DR2. After probing previously unexplored heliocentric distances of d < 20 kpc with an extreme-deconvolution (XD) technique, we find no sign of a dwarf galaxy in any of these fields despite Gaia's excellent astrometric accuracy. O…
Testing statistical isotropy in cosmic microwave background polarization maps
Rath, Pranati K.; Samal, Pramoda Kumar; Panda, Srikanta +2 more
We apply our symmetry based Power tensor technique to test conformity of PLANCK Polarization maps with statistical isotropy. On a wide range of angular scales (l = 40 - 150), our preliminary analysis detects many statistically anisotropic multipoles in foreground cleaned full sky PLANCK polarization maps viz., COMMANDER and NILC. We also study the…
The two ultraluminous X-ray sources in the galaxy NGC 925
Mereghetti, S.; Wolter, A.; Esposito, P. +7 more
NGC 925 ULX-1 and ULX-2 are two ultraluminous X-ray sources (ULXs) in the galaxy NGC 925, at a distance of 8.5 Mpc. For the first time, we analysed high quality, simultaneous XMM-Newton and NuSTAR data of both sources. Although at a first glance ULX-1 resembles an intermediate mass black hole candidate (IMBH) because of its high X-ray luminosity […
Unveiling the inner morphology and gas kinematics of NGC 5135 with ALMA
Cimatti, A.; Pozzi, F.; Massardi, M. +5 more
The local Seyfert 2 galaxy NGC 5135, thanks to its almost face-on appearance, a bulge overdensity of stars, the presence of a large-scale bar, an active galactic nucleus (AGN) and a supernova remnant, is an excellent target to investigate the dynamics of inflows, outflows, star formation, and AGN feedback. Here, we present a reconstruction of the …
A photometric analysis of Abell 1689: two-dimensional multistructure decomposition, morphological classification and the Fundamental Plane
Dalla Bontà, E.; Davies, R. L.; D'Eugenio, F. +2 more
We present a photometric analysis of 65 galaxies in the rich cluster Abell 1689 at z = 0.183, using the Hubble Space Telescope Advanced Camera for Surveys archive images in the rest-frame V band. We perform two-dimensional multicomponent photometric decomposition of each galaxy adopting different models of the surface-brightness distribution. We p…
LCO observations of a super-critical distorted pulsation in the roAp star J0855 (TYC 2488-1241-1)
Bowman, Dominic M.; Sefako, Ramotholo R.; Holdsworth, Daniel L. +1 more
We report the results of a 60-h photometric campaign of a rapidly oscillating Ap star, J0855 (TYC 2488-1241-1). We have utilized the multi-site Las Cumbres Observatory's (LCO) 0.4-m telescopes to obtain short cadence B-band observations of an roAp star previously lacking detailed study. Our observations confirm the rotation period presented in the…
Electron-impact excitation of diatomic hydride cations II: OH+ and SH+
Tennyson, Jonathan; Faure, Alexandre; Hamilton, James R.
R-matrix calculations combined with the adiabatic-nuclei-rotation and Coulomb-Born approximations are used to compute electron-impact rotational rate coefficients for two open-shell diatomic cations of astrophysical interest: the hydoxyl and sulphanyl ions, OH+ and SH+. Hyperfine resolved rate coefficients are deduced using t…
The gas and stellar mass of low-redshift damped Lyman-α absorbers
Prochaska, J. Xavier; Neeleman, Marcel; Kanekar, Nissim +1 more
We report Hubble Space Telescope Cosmic Origins Spectrograph far-ultraviolet and Arecibo Telescope H I 21 cm spectroscopy of six damped and sub-damped Lyman-α absorbers (DLAs and sub-DLAs, respectively) at z ≲ 0.1, which have yielded estimates of their H I column density, metallicity and atomic gas mass. This significantly increases the number of …