Search Publications
Calibrating the cosmic distance scale ladder: the role of the sound-horizon scale and the local expansion rate as distance anchors
Verde, Licia; Riess, Adam; Jimenez, Raul +1 more
We exploit cosmological model-independent measurements of the expansion history of the Universe to provide a cosmic distance ladder. These are supernovae Type Ia used as standard candles (at redshift between 0.01 and 1.3) and baryon acoustic oscillations (at redshifts between 0.1 and 0.8) as standard rulers. We calibrate (anchor) the ladder in two…
Faint dwarfs as a test of DM models: WDM versus CDM
Mayer, L.; Behroozi, P.; Madau, P. +12 more
We use high-resolution Hydro+N-Body cosmological simulations to compare the assembly and evolution of a small field dwarf (stellar mass ∼106-7 M⊙, total mass 1010 M⊙) in Λ-dominated cold dark matter (CDM) and 2 keV warm dark matter (WDM) cosmologies. We find that star formation (SF) in the WDM model is r…
The evolution of the cold interstellar medium in galaxies following a starburst
da Cunha, E.; Nesvadba, N.; Mortier, A. +4 more
We present the evolution of dust and molecular gas properties in a sample of 11 z ∼ 0.03 starburst to post-starburst (PSB) galaxies selected to span an age sequence from ongoing starburst to 1 Gyr after the starburst ended. All PSBs harbour significant molecular gas and dust reservoirs and residual star formation, indicating that complete quenchin…
The composition of a disrupted extrasolar planetesimal at SDSS J0845+2257 (Ton 345)
Gänsicke, B. T.; Pala, A. F.; Breedt, E. +4 more
We present a detailed study of the metal-polluted DB white dwarf SDSS J0845+2257 (Ton 345). Using high-resolution Hubble Space Telescope/Cosmic Origins Spectrograph and Very Large Telescope spectroscopy, we have detected hydrogen and 11 metals in the atmosphere of the white dwarf. The origin of these metals is almost certainly the circumstellar di…
The dust grain size-stellar luminosity trend in debris discs
Pawellek, Nicole; Krivov, Alexander V.
The cross-section of material in debris discs is thought to be dominated by the smallest grains that can still stay in bound orbits despite the repelling action of stellar radiation pressure. Thus the minimum (and typical) grain size smin is expected to be close to the radiation pressure blowout size sblow. Yet a recent analy…
Effect of primordial magnetic fields on the ionization history
Finelli, F.; Paoletti, D.; Rubiño-Martín, J. A. +1 more
Primordial magnetic fields (PMF) damp at scales smaller than the photon diffusion and free-streaming scale. This leads to heating of ordinary matter (electrons and baryons), which affects both the thermal and ionization history of our Universe. Here, we study the effect of heating due to ambipolar diffusion and decaying magnetic turbulence. We fin…
Low-level accretion in neutron star X-ray binaries
Altamirano, D.; Degenaar, N.; Wijnands, R. +5 more
We search the literature for reports on the spectral properties of neutron star low-mass X-ray binaries when they have accretion luminosities between 1034 and 1036 erg s-1, corresponding to roughly 0.01-1 per cent of the Eddington accretion rate for a neutron star. We found that in this luminosity range the photon …
Hubble Frontier Fields: the geometry and dynamics of the massive galaxy cluster merger MACSJ0416.1-2403
Richard, Johan; Massey, Richard; Kneib, Jean-Paul +13 more
We use a joint optical/X-ray analysis to constrain the geometry and history of the ongoing merging event in the massive galaxy cluster MACSJ0416.1-2403 (z = 0.397). Our investigation of cluster substructure rests primarily on a combined strong- and weak-lensing mass reconstruction based on the deep, high-resolution images obtained for the Hubble F…
Detection of two power-law tails in the probability distribution functions of massive GMCs.
Abergel, A.; Hill, T.; Arzoumanian, D. +20 more
We report the novel detection of complex high column density tails in the probability distribution functions (PDFs) for three high-mass star-forming regions (CepOB3, MonR2, NGC 6334), obtained from dust emission observed with Herschel. The low column density range can be fitted with a lognormal distribution. A first power-law tail starts above an …
Suzaku observations of Mrk 335: confronting partial covering and relativistic reflection
Fabian, A. C.; Komossa, S.; Gallo, L. C. +7 more
We report on the deepest X-ray observation of the narrow-line Seyfert 1 galaxy Mrk 335 in the low-flux state obtained with Suzaku. The data are compared to a 2006 high-flux Suzaku observation when the source was ∼10 times brighter. Describing the two flux levels self-consistently with partial covering models would require extreme circumstances, as…