Search Publications
The Semiforbidden C III] λ1909 Emission in the Rest-ultraviolet Spectra of Green Pea Galaxies
Ferguson, Henry C.; Ravindranath, Swara; Jaskot, Anne +2 more
We used the Space Telescope Imaging Spectrograph on the Hubble Space Telescope (HST) to observe the semiforbidden C III] λλ1907, 1909 doublet emission in green pea galaxies at 0.13 ≤ z ≤ 0.3. We detect C III] emission in 7/10 galaxies with C III] equivalent widths (EWs) that range from 2 to 10 Å, confirming that C III] emission is almost ubiquitou…
Evidence for a Highly Opaque Large-scale Galaxy Void at the End of Reionization
Ouchi, Masami; Shibuya, Takatoshi; Kashino, Daichi +2 more
We present evidence that a region of high effective Lyα optical depth at z ∼ 5.7 is associated with an underdense region at the tail end of cosmic reionization. We carried out a survey of Lyman-break Galaxies (LBGs) using Subaru Hyper Suprime-Cam in the field of the z = 5.98 quasar J0148+0600, whose spectrum presents an unusually long (∼160 cMpc) …
Improving galaxy clustering measurements with deep learning: analysis of the DECaLS DR7 data
Ross, Ashley J.; Seo, Hee-Jong; Rezaie, Mehdi +1 more
Robust measurements of cosmological parameters from galaxy surveys rely on our understanding of systematic effects that impact the observed galaxy density field. In this paper, we present, validate, and implement the idea of adopting the systematics mitigation method of artificial neural networks for modelling the relationship between the target g…
Five New Post-main-sequence Debris Disks with Gaseous Emission
Hermes, J. J.; Clemens, J. C.; Lai, Samuel +13 more
Observations of debris disks, the products of the collisional evolution of rocky planetesimals, can be used to trace planetary activity across a wide range of stellar types. The most common end points of stellar evolution are no exception, as debris disks have been observed around several dozen white dwarf stars. But instead of planetary formation…
A HARPS RV search for planets around young nearby stars
Meunier, N.; Messina, S.; Keppler, M. +11 more
Context. Young nearby stars are good candidates in the search for planets with both radial velocity (RV) and direct imaging techniques. This, in turn, allows for the computation of the giant planet occurrence rates at all separations. The RV search around young stars is a challenge as they are generally faster rotators than older stars of similar …
The synthetic Emission Line COSMOS catalogue: Hα and [O II] galaxy luminosity functions and counts at 0.3 < z < 2.5
Ilbert, Olivier; Saito, Shun; Yabe, Kiyoto +3 more
Star-forming galaxies with strong nebular and collisional emission lines are privileged target galaxies in forthcoming cosmological large galaxy redshift surveys. We use the COSMOS2015 photometric catalogue to model galaxy spectral energy distributions and emission-line fluxes. We adopt an empirical but physically motivated model that uses informa…
Ellerman bombs and UV bursts: reconnection at different atmospheric layers
Nóbrega-Siverio, Daniel; Ortiz, Ada; Hansteen, Viggo H. +1 more
The emergence of magnetic flux through the photosphere and into the outer solar atmosphere produces, amongst other dynamical phenomena, Ellerman bombs (EBs), which are observed in the wings of Hα and are due to magnetic reconnection in the photosphere below the chromospheric canopy. Signs of magnetic reconnection are also observed in other spectra…
The CARMENES search for exoplanets around M dwarfs. Characterization of the nearby ultra-compact multiplanetary system YZ Ceti
Amado, P. J.; Bauer, F. F.; Caballero, J. A. +38 more
Context. The nearby ultra-compact multiplanetary system YZ Ceti consists of at least three planets, and a fourth tentative signal. The orbital period of each planet is the subject of discussion in the literature due to strong aliasing in the radial velocity data. The stellar activity of this M dwarf also hampers significantly the derivation of the…
The Relative Emission from Chromospheres and Coronae: Dependence on Spectral Type and Age
Brown, Alexander; Wheatley, Peter J.; France, Kevin +12 more
Extreme-ultraviolet and X-ray emission from stellar coronae drives mass loss from exoplanet atmospheres, and ultraviolet emission from stellar chromospheres drives photochemistry in exoplanet atmospheres. Comparisons of the spectral energy distributions of host stars are, therefore, essential for understanding the evolution and habitability of exo…
Coordination within the remote sensing payload on the Solar Orbiter mission
Williams, D.; Woch, J.; Peter, H. +71 more
Context. To meet the scientific objectives of the mission, the Solar Orbiter spacecraft carries a suite of in-situ (IS) and remote sensing (RS) instruments designed for joint operations with inter-instrument communication capabilities. Indeed, previous missions have shown that the Sun (imaged by the RS instruments) and the heliosphere (mainly samp…