Search Publications
A physical model of the broad-band continuum of AGN and its implications for the UV/X relation and optical variability
Done, Chris; Kubota, Aya
We develop a new spectral model for the broad-band spectral energy distribution (SED) of active galactic nuclei (AGN). This includes an outer standard disc, an inner warm Comptonizing region to produce the soft X-ray excess and a hot corona. We tie these together energetically by assuming Novikov-Thorne emissivity, and use this to define a size sc…
Confirming chemical clocks: asteroseismic age dissection of the Milky Way disc(s)
Serenelli, A. M.; Johnson, J. A.; Lund, M. N. +22 more
Investigations of the origin and evolution of the Milky Way disc have long relied on chemical and kinematic identifications of its components to reconstruct our Galactic past. Difficulties in determining precise stellar ages have restricted most studies to small samples, normally confined to the solar neighbourhood. Here, we break this impasse wit…
Global Climate and Atmospheric Composition of the Ultra-hot Jupiter WASP-103b from HST and Spitzer Phase Curve Observations
Fortney, Jonathan J.; Stevenson, Kevin B.; Désert, Jean-Michel +13 more
We present thermal phase curve measurements for the hot Jupiter WASP-103b observed with Hubble/WFC3 and Spitzer/IRAC. The phase curves have large amplitudes and negligible hotspot offsets, indicative of poor heat redistribution to the nightside. We fit the phase variation with a range of climate maps and find that a spherical harmonics model gener…
A detached stellar-mass black hole candidate in the globular cluster NGC 3201
Brinchmann, Jarle; Weilbacher, Peter M.; Kamann, Sebastian +7 more
As part of our massive spectroscopic survey of 25 Galactic globular clusters with MUSE, we performed multiple epoch observations of NGC 3201 with the aim of constraining the binary fraction. In this cluster, we found one curious star at the main-sequence turn-off with radial velocity variations of the order of 100 km s- 1, indicating th…
MICROSCOPE Mission: First Constraints on the Violation of the Weak Equivalence Principle by a Light Scalar Dilaton
Bergé, Joel; Pernot-Borràs, Martin; Uzan, Jean-Philippe +3 more
The existence of a light or massive scalar field with a coupling to matter weaker than gravitational strength is a possible source of violation of the weak equivalence principle. We use the first results on the Eötvös parameter by the MICROSCOPE experiment to set new constraints on such scalar fields. For a massive scalar field of mass smaller tha…
Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2015
Oberst, J.; A'Hearn, M. F.; Klioner, S. A. +15 more
This report continues the practice where the IAU Working Group on Cartographic Coordinates and Rotational Elements revises recommendations regarding those topics for the planets, satellites, minor planets, and comets approximately every 3 years. The Working Group has now become a "functional working group" of the IAU, and its membership is open to…
Rotation in [C II]-emitting gas in two galaxies at a redshift of 6.8
Holwerda, Benne W.; Carniani, Stefano; Maiolino, Roberto +10 more
The earliest galaxies are thought to have emerged during the first billion years of cosmic history, initiating the ionization of the neutral hydrogen that pervaded the Universe at this time. Studying this ‘epoch of reionization’ involves looking for the spectral signatures of ancient galaxies that are, owing to the expansion of the Universe, now v…
The [C II] emission as a molecular gas mass tracer in galaxies at low and high redshifts
Daddi, E.; Elbaz, D.; Dickinson, M. +19 more
We present ALMA Band 9 observations of the [C II]158 µm emission for a sample of 10 main-sequence galaxies at redshift z ∼ 2, with typical stellar masses (log M⋆/M⊙ ∼ 10.0-10.9) and star formation rates (∼35-115 M⊙ yr-1). Given the strong and well-understood evolution of the interstellar medium fro…
A massive core for a cluster of galaxies at a redshift of 4.3
Béthermin, M.; Murphy, E. J.; Greve, T. R. +35 more
Massive galaxy clusters have been found that date to times as early as three billion years after the Big Bang, containing stars that formed at even earlier epochs1-3. The high-redshift progenitors of these galaxy clusters—termed `protoclusters'—can be identified in cosmological simulations that have the highest overdensities (greater-th…
GAMA/G10-COSMOS/3D-HST: the 0 < z < 5 cosmic star formation history, stellar-mass, and dust-mass densities
Wilkins, Stephen M.; Holwerda, Benne; Conselice, Christopher J. +30 more
We use the energy-balance code MAGPHYS to determine stellar and dust masses, and dust corrected star formation rates for over 200 000 GAMA galaxies, 170 000 G10-COSMOS galaxies, and 200 000 3D-HST galaxies. Our values agree well with previously reported measurements and constitute a representative and homogeneous data set spanning a broad range in…