Search Publications
Lyman-α spectral properties of five newly discovered Lyman continuum emitters
Schaerer, D.; Thuan, T. X.; Verhamme, A. +4 more
Aims: We have recently reported the discovery of five low redshift Lyman continuum (LyC) emitters (LCEs) with absolute escape fractions fescLyC that range from 6 to 13%, higher than previously found and that more than double the number of low redshift LCEs. We use these observations to test theoretical predictions about …
Echo of interactions in the dark sector
Nunes, Rafael C.; Kumar, Suresh
We investigate the observational constraints on an interacting vacuum energy scenario with two different neutrino schemes (with and without a sterile neutrino) using the most recent data from cosmic microwave background (CMB) temperature and polarization anisotropy, baryon acoustic oscillations (BAO), type Ia supernovae from JLA sample and structu…
The MUSE Hubble Ultra Deep Field Survey. VIII. Extended Lyman-α haloes around high-z star-forming galaxies
Bacon, Roland; Blaizot, Jérémy; Garel, Thibault +17 more
We report the detection of extended Lyα haloes around 145 individual star-forming galaxies at redshifts 3 ≤ z ≤ 6 in the Hubble Ultra Deep Field observed with the Multi-Unit Spectroscopic Explorer (MUSE) at ESO-VLT. Our sample consists of continuum-faint (- 15 ≥ MUV ≥ -22) Lyα emitters (LAEs). Using a 2D, two-component (continuum-like a…
The e-ASTROGAM mission. Exploring the extreme Universe with gamma rays in the MeV - GeV range
Ghisellini, G.; Hanlon, L.; Mereghetti, S. +71 more
e-ASTROGAM (`enhanced ASTROGAM') is a breakthrough Observatory space mission, with a detector composed by a Silicon tracker, a calorimeter, and an anticoincidence system, dedicated to the study of the non-thermal Universe in the photon energy range from 0.3 MeV to 3 GeV - the lower energy limit can be pushed to energies as low as 150 keV, albeit w…
ALMA unveils rings and gaps in the protoplanetary system HD 169142 : signatures of two giant protoplanets
Fedele, D.; Henning, Th.; Miotello, A. +6 more
The protoplanetary system HD 169142 is one of the few cases where a potential candidate protoplanet has recently been detected by direct imaging in the near-infrared. To study the interaction between the protoplanet and the disk itself, observations of the gas and dust surface density structure are needed. This paper reports new ALMA observations …
Cosmological constraints on exotic injection of electromagnetic energy
Lesgourgues, Julien; Poulin, Vivian; Serpico, Pasquale D.
We compute cosmic microwave background (CMB) anisotropy constraints on exotic forms of energy injection in electromagnetic (e.m.) channels over a large range of timescales. We show that these constraints are very powerful around or just after recombination, although CMB keeps some sensitivity e.g. to decaying species with lifetimes as long as 10
An ultrahot gas-giant exoplanet with a stratosphere
Deming, Drake; Knutson, Heather; Nikolov, Nikolay +24 more
Infrared radiation emitted from a planet contains information about the chemical composition and vertical temperature profile of its atmosphere. If upper layers are cooler than lower layers, molecular gases will produce absorption features in the planetary thermal spectrum. Conversely, if there is a stratosphere—where temperature increases with al…
Growing supermassive black holes in the late stages of galaxy mergers are heavily obscured
Sanders, D. B.; Harrison, F.; Stern, D. +10 more
Mergers of galaxies are thought to cause significant gas inflows to the inner parsecs, which can activate rapid accretion on to supermassive black holes (SMBHs), giving rise to active galactic nuclei (AGN). During a significant fraction of this process, SMBHs are predicted to be enshrouded by gas and dust. Studying 52 galactic nuclei in infrared-s…
HD 209458b in new light: evidence of nitrogen chemistry, patchy clouds and sub-solar water
Madhusudhan, Nikku; MacDonald, Ryan J.
Interpretations of exoplanetary transmission spectra have been undermined by apparent obscuration due to clouds/hazes. Debate rages on whether weak H2O features seen in exoplanet spectra are due to clouds or inherently depleted oxygen. Assertions of solar H2O abundances have relied on making a priori model assumptions, for ex…
iPTF16geu: A multiply imaged, gravitationally lensed type Ia supernova
Sollerman, J.; Kulkarni, S. R.; Sullivan, M. +31 more
We report the discovery of a multiply imaged, gravitationally lensed type Ia supernova, iPTF16geu (SN 2016geu), at redshift z = 0.409. This phenomenon was identified because the light from the stellar explosion was magnified more than 50 times by the curvature of space around matter in an intervening galaxy. We used high-spatial-resolution observa…