Search Publications
The electron-capture origin of supernova 2018zd
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Kelly, Patrick L. +27 more
In the transitional mass range (~8-10 solar masses) between white dwarf formation and iron core-collapse supernovae, stars are expected to produce an electron-capture supernova. Theoretically, these progenitors are thought to be super-asymptotic giant branch stars with a degenerate O + Ne + Mg core, and electron capture onto Ne and Mg nuclei shoul…
Evidence for GN-z11 as a luminous galaxy at redshift 10.957
Ho, Luis C.; Fan, Xiaohui; Jiang, Linhua +9 more
GN-z11 was photometrically selected as a luminous star-forming galaxy candidate at redshift z > 10 on the basis of Hubble Space Telescope imaging data1. Follow-up Hubble Space Telescope near-infrared grism observations detected a continuum break that was explained as the Lyα break corresponding to z =11.0 9−0.12+0.08<…
A gravitationally lensed supernova with an observable two-decade time delay
Richard, Johan; Whitaker, Katherine E.; Brammer, Gabriel B. +5 more
When the light from a distant object passes very near to a foreground galaxy or cluster, gravitational lensing can cause it to appear as multiple images on the sky1. If the source is variable, it can be used to constrain the cosmic expansion rate2 and dark energy models3. Achieving these cosmological goals requires…
A unique hot Jupiter spectral sequence with evidence for compositional diversity
Fortney, Jonathan J.; Sing, David K.; López-Morales, Mercedes +11 more
The emergent spectra of close-in, giant exoplanets (`hot Jupiters') are expected to be distinct from those of self-luminous objects with similar effective temperatures because hot Jupiters are primarily heated from above by their host stars rather than internally from the release of energy from their formation1. Theoretical models predi…
A hidden population of high-redshift double quasars unveiled by astrometry
Shen, Yue; Oguri, Masamune; Lazio, Joseph +6 more
Galaxy mergers occur frequently in the early Universe1 and bring multiple supermassive black holes (SMBHs) into the nucleus, where they may eventually coalesce. Identifying post-merger-scale (that is, less than around a few kpc) dual SMBHs is a critical pathway to understanding their dynamical evolution and successive mergers2
A new class of fossil fragments from the hierarchical assembly of the Galactic bulge
Dalessandro, E.; Saracino, S.; Valenti, E. +12 more
The formation and evolutionary processes of galaxy bulges are still unclear, and the presence of young stars in the bulge of the Milky Way is largely debated. We recently demonstrated that Terzan 5, in the Galactic bulge, is a complex stellar system hosting stars with very different ages and a striking chemical similarity to the field population. …
Haze evolution in temperate exoplanet atmospheres through surface energy measurements
Fortney, Jonathan J.; Moran, Sarah E.; Valenti, Jeff A. +13 more
Photochemical hazes are important opacity sources in temperate exoplanet atmospheres, hindering current observations from characterizing exoplanet atmospheric compositions. The haziness of an atmosphere is determined by the balance between haze production and removal. However, the material-dependent removal physics of the haze particles are curren…
A sublimated water atmosphere on Ganymede detected from Hubble Space Telescope observations
Saur, Joachim; Roth, Lorenz; Grodent, Denis +5 more
Ganymede's atmosphere is produced by charged particle sputtering and sublimation of its icy surface. Previous far-ultraviolet observations of the O I 1,356 å and O I 1,304 å oxygen emissions were used to infer sputtered molecular oxygen (O2) as an atmospheric constituent, but an expected sublimated water (H2O) component remai…
Transforming gas-rich low-mass disky galaxies into ultra-diffuse galaxies by ram pressure
Fabricant, Daniel; Yagi, Masafumi; Afanasiev, Anton V. +4 more
Faint extended elliptically shaped ultra-diffuse galaxies and slightly brighter and more compact dwarf elliptical and lenticular stellar systems are common in galaxy clusters. Their poorly constrained evolutionary paths can be studied by identifying young ultra-diffuse galaxy and dwarf elliptical analogues populated with bright, massive stars. Usi…
Slowly cooling white dwarfs in M13 from stable hydrogen burning
Cadelano, Mario; Pallanca, Cristina; Dalessandro, Emanuele +5 more
White dwarfs (WDs) are the final evolutionary product of the vast majority of stars in the Universe. They are electron-degenerate structures characterized by no stable thermonuclear activity, and their evolution is generally described as a pure cooling process. Their cooling rate is adopted as cosmic chronometer to constrain the age of several Gal…