Search Publications
Gaia Data Release 1. Cross-match with external catalogues. Algorithm and results
Marinoni, S.; Marrese, P. M.; Fabrizio, M. +1 more
Context. Although the Gaia catalogue on its own will be a very powerful tool, it is the combination of this highly accurate archive with other archives that will truly open up amazing possibilities for astronomical research. The advanced interoperation of archives is based on cross-matching, leaving the user with the feeling of working with one si…
Determining the torus covering factors for a sample of type 1 AGN in the local Universe
Done, Chris; Gandhi, Poshak; Dewangan, Gulab C. +4 more
In the unified scheme of active galactic nuclei, a dusty torus absorbs and then reprocesses a fraction of the intrinsic luminosity which is emitted at longer wavelengths. Thus, subject to radiative transfer corrections, the fraction of the sky covered by the torus as seen from the central source (known as the covering factor fc) can be …
Galactoseismology and the local density of dark matter
Widrow, Lawrence M.; Banik, Nilanjan; Dodelson, Scott
We model vertical breathing mode perturbations in the Milky Way's stellar disc and study their effects on estimates of the local dark matter density, surface density, and vertical force. Evidence for these perturbations, which involve compression and expansion of the Galactic disc perpendicular to the mid-plane, comes from three different surveys …
Polarization due to rotational distortion in the bright star Regulus
Bailey, Jeremy; Cotton, Daniel V.; Howarth, Ian D. +4 more
Polarization in stars was first predicted by Chandrasekhar1, who calculated a substantial linear polarization at the stellar limb for a pure electron-scattering atmosphere. This polarization will average to zero when integrated over a spherical star but could be detected if the symmetry was broken, for example, by the eclipse of a binar…
X-ray constraints on the fraction of obscured active galactic nuclei at high accretion luminosities
Georgakakis, A.; Salvato, M.; Liu, Z. +9 more
The wide-area XMM-XXL X-ray survey is used to explore the fraction of obscured active galactic nuclei (AGNs) at high accretion luminosities, LX(2-10 keV) ≳ 1044 erg s - 1, and out to redshift z ≈ 1.5. The sample covers an area of about 14 deg2 and provides constraints on the space density of powerful AGN…
Red but not dead: unveiling the star-forming far-infrared spectral energy distribution of SpARCS brightest cluster galaxies at 0 < z < 1.8
Lidman, C.; Surace, J.; Muzzin, A. +8 more
We present the results of a Spitzer/Herschel infrared photometric analysis of the largest (716) and the highest-redshift (z = 1.8) sample of brightest cluster galaxies (BCGs), those from the Spitzer Adaptation of the Red-Sequence Cluster Survey Given the tension that exists between model predictions and recent observations of BCGs at z < 2, we …
Two Small Transiting Planets and a Possible Third Body Orbiting HD 106315
de Pater, Imke; Knutson, Heather A.; Schlieder, Joshua E. +21 more
The masses, atmospheric makeups, spin-orbit alignments, and system architectures of extrasolar planets can be best studied when the planets orbit bright stars. We report the discovery of three bodies orbiting HD 106315, a bright (V = 8.97 mag) F5 dwarf targeted by our K2 survey for transiting exoplanets. Two small transiting planets are found to h…
Type 2 AGN Host Galaxies in the Chandra-COSMOS Legacy Survey: No Evidence of AGN-driven Quenching
Schawinski, Kevin; Elvis, Martin; Lusso, Elisabeta +16 more
We investigate the star formation properties of a large sample of ∼2300 X-ray-selected Type 2 Active Galactic Nuclei (AGNs) host galaxies out to z∼ 3 in the Chandra COSMOS Legacy Survey in order to understand the connection between the star formation and nuclear activity. Making use of the existing multi-wavelength photometric data available in th…
ALMA imaging of C2H emission in the disk of NGC 1068
Tacconi, L. J.; Hunt, L. K.; Krips, M. +16 more
Aims: We study the feedback of star formation and nuclear activity on the chemistry of molecular gas in NGC 1068, a nearby (D = 14 Mpc) Seyfert 2 barred galaxy, by analyzing whether the abundances of key molecular species such as ethynyl (C2H), which is a classical tracer of photon dominated regions (PDR), change in the different e…
First Scattered-light Images of the Gas-rich Debris Disk around 49 Ceti
Debes, John H.; Roberge, Aki; Schneider, Glenn +31 more
We present the first scattered-light images of the debris disk around 49 Ceti, a ∼40 Myr A1 main-sequence star at 59 pc, famous for hosting two massive dust belts as well as large quantities of atomic and molecular gas. The outer disk is revealed in reprocessed archival Hubble Space Telescope NICMOS-F110W images, as well as new coronagraphic H-ban…