Search Publications
Ultra-faint high-redshift galaxies in the Frontier Fields
Salvaterra, R.; Vanzella, E.; Ferrara, A. +1 more
By combining cosmological simulations with Frontier Field (FF) project lens models, we find that, in the most optimistic case, galaxies as faint as m ≈ 33-34 (AB magnitude at 1.6 µm) can be detected in the Frontier Fields. Such faint galaxies are hosted by dark matter haloes of mass ~109 M⊙ and dominate the ionizing pho…
A signature of chromospheric activity in brown dwarfs revealed by 2.5-5.0 µm AKARI spectra
Yamamura, I.; Sorahana, S.; Suzuki, T. K.
We propose that the 2.7-µm H2O, 3.3-µm CH4 and 4.6-µm CO absorption bands can be good tracers of chromospheric activity in brown dwarfs. In our previous study, we found that there are difficulties in explaining entire spectra between 1.0 and 5.0 µm with the unified cloudy model (UCM), a brown dwarf atm…
Radio-gamma-ray connection and spectral evolution in 4C +49.22 (S4 1150+49): the Fermi, Swift and Planck view
D'Elia, V.; González-Nuevo, J.; Lähteenmäki, A. +22 more
The Large Area Telescope on board the Fermi Gamma-ray Space Telescope detected a strong γ-ray flare on 2011 May 15 from a source identified as 4C +49.22, a flat spectrum radio quasar (FSRQ) also known as S4 1150+49. This blazar, characterized by a prominent radio-optical-X-ray jet, was in a low γ-ray activity state during the first years of Fermi …
The PEP survey: infrared properties of radio-selected AGN
Berta, S.; Magnelli, B.; Lutz, D. +6 more
By exploiting the VLA-COSMOS and the Herschel-PEP surveys, we investigate the far-infrared (FIR) properties of radio-selected AGN. To this purpose, from VLA-COSMOS we considered the 1537, F1.4 GHz ≥ 0.06 mJy sources with a reliable redshift estimate, and sub-divided them into star-forming galaxies and AGN solely on the basis of their ra…
Broad absorption line variability in radio-loud quasars
Brandt, W. N.; Welling, C. A.; Miller, B. P. +2 more
We investigate C IV broad absorption line (BAL) variability within a sample of 46 radio-loud quasars (RLQs), selected from Sloan Digital Sky Survey (SDSS)/Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) data to include both core-dominated (39) and lobe-dominated (7) objects. The sample consists primarily of high-ionization BAL quasars,…
The physical nature of the 8 o'clock arc based on near-IR IFU spectroscopy with SINFONI
Vegetti, S.; Allam, S.; Brinchmann, J. +3 more
We present an analysis of near-infrared integral field unit spectroscopy of the 8 o'clock arc, a gravitationally lensed Lyman break galaxy, taken with SINFONI. We explore the shape of the spatially resolved Hβ profile and demonstrate that we can decompose it into three components that partially overlap (spatially) but are distinguishable when we i…
Fe Kα line in hard X-ray emitting symbiotic stars
Eze, R. N. C.
The 6.4 keV iron emission line is typically created by irradiation of the neutral (or low ionized) iron by a hard X-ray source. Whereas the 6.7 and 7.0 keV emission lines are mainly produced by photoionization and collisional excitation in hot plasma, the 6.4 keV fluorescence line is typically a signature of either reflection from an accretion dis…
M2M modelling of the Galactic disc via PRIMAL: fitting to Gaia error added data
Kawata, Daisuke; Hunt, Jason A. S.
We have adapted our made-to-measure (M2M) algorithm PRIMAL to use mock Milky Way like data constructed from an N-body barred galaxy with a boxy bulge in a known dark matter potential. We use M0 giant stars as tracers, with the expected error of the ESA (European Space Agency) space astrometry mission Gaia. We demonstrate the process of constructin…
The local standard of rest from data on young objects with account for the Galactic spiral density wave
Bobylev, V. V.; Bajkova, A. T.
To estimate the peculiar velocity of the Sun with respect to the local standard of rest (LSR), we used young objects in the Solar neighbourhood with distance measurement errors within 10-15 per cent. These objects were the nearest Hipparcos stars of spectral classes O-B2.5, masers with trigonometric parallaxes measured by means of very long baseli…
No shock across part of a radio relic in the merging galaxy cluster ZwCl 2341.1+0000?
Simionescu, A.; van Weeren, R. J.; Brüggen, M. +2 more
The galaxy cluster ZwCl 2341.1+0000 is a merging system at z = 0.27, which hosts two radio relics and a central, faint, filamentary radio structure. The two radio relics have unusually flat integrated spectral indices of -0.49 ± 0.18 and -0.76 ± 0.17, values that cannot be easily reconciled with the theory of standard diffusive shock acceleration …