Search Publications
Ejecta from the DART-produced active asteroid Dimorphos
Granvik, Mikael; Kolokolova, Ludmilla; Weaver, Harold A. +61 more
Some active asteroids have been proposed to be formed as a result of impact events1. Because active asteroids are generally discovered by chance only after their tails have fully formed, the process of how impact ejecta evolve into a tail has, to our knowledge, not been directly observed. The Double Asteroid Redirection Test (DART) miss…
A structured jet explains the extreme GRB 221009A
Kouveliotou, Chryssa; Buckley, David A. H.; Hammerstein, Erica +29 more
Long-duration gamma-ray bursts (GRBs) are powerful cosmic explosions, signaling the death of massive stars. Among them, GRB 221009A is by far the brightest burst ever observed. Because of its enormous energy ( E iso ≈ 10 55 erg) and proximity ( z ≈ 0.15), GRB 221009A is an exceptionally rare event that pushes the limits of our theories. We present…
Cold Jupiters and improved masses in 38 Kepler and K2 small planet systems from 3661 HARPS-N radial velocities. No excess of cold Jupiters in small planet systems
Vanderburg, A.; Poretti, E.; Sozzetti, A. +31 more
The exoplanet population characterized by relatively short orbital periods (P < 100 d) around solar-type stars is dominated by super-Earths and sub-Neptunes. However, these planets are missing in our Solar System and the reason behind this absence is still unknown. Two theoretical scenarios invoke the role of Jupiter as the possible culprit: Ju…
Finding Peas in the Early Universe with JWST
Kim, Keunho J.; Malhotra, Sangeeta; Pharo, John +6 more
The Early Release Observations (EROs) of JWST beautifully demonstrate the promise of JWST in characterizing the universe at Cosmic Dawn. We analyze the Near Infrared Spectrograph ERO spectra of three z ~ 8 galaxies to determine their metallicities, gas temperatures, and ionization. These galaxies offer the first opportunity to understand the physi…
JADES: Discovery of extremely high equivalent width Lyman-α emission from a faint galaxy within an ionized bubble at z = 7.3
Chevallard, Jacopo; Maseda, Michael V.; Carniani, Stefano +44 more
We report the discovery of a remarkable Lyα emitting galaxy at z = 7.2782, JADES-GS+53.16746−27.7720 (shortened to JADES-GS-z7-LA), with rest-frame equivalent width, EW0(Lyα) = 388.0 ± 88.8 Å and UV magnitude −17.0. The spectroscopic redshift is confirmed via rest-frame optical lines [O II], Hβ and [O III] in its JWST/NIRSpec Micro-Shut…
Constraints on the Hubble constant from supernova Refsdal's reappearance
Treu, Tommaso; Broadhurst, Tom; Filippenko, Alexei V. +27 more
The gravitationally lensed supernova Refsdal appeared in multiple images produced through gravitational lensing by a massive foreground galaxy cluster. After the supernova appeared in 2014, lens models of the galaxy cluster predicted that an additional image of the supernova would appear in 2015, which was subsequently observed. We use the time de…
The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems I: High-contrast Imaging of the Exoplanet HIP 65426 b from 2 to 16 µm
Henning, Thomas; Fortney, Jonathan J.; Carter, Aarynn L. +108 more
We present JWST Early Release Science coronagraphic observations of the super-Jupiter exoplanet, HIP 65426b, with the Near-Infrared Camera (NIRCam) from 2 to 5 µm, and with the Mid-Infrared Instrument (MIRI) from 11 to 16 µm. At a separation of ~0.″82 (87 ${}_{-31}^{+108}$ au), HIP 65426b is clearly detected in all seven of our observa…
A 3D Drizzle Algorithm for JWST and Practical Application to the MIRI Medium Resolution Spectrometer
Law, David R.; Vandenbussche, Bart; Patapis, Polychronis +4 more
We describe an algorithm for application of the classic "drizzle" technique to produce 3D spectral cubes using data obtained from the slicer-type integral field unit (IFU) spectrometers on board the James Webb Space Telescope. This algorithm relies upon the computation of overlapping volume elements (composed of two spatial dimensions and one spec…
Gaia Data Release 3. Specific processing and validation of all sky RR Lyrae and Cepheid stars: The Cepheid sample
Szabados, L.; Audard, M.; Plachy, E. +19 more
Context. Cepheids are pulsating stars that play a crucial role in several astrophysical contexts. Among the different types, the Classical Cepheids are fundamental tools for the calibration of the extragalactic distance ladder. They are also powerful stellar population tracers in the context of Galactic studies. The Gaia Third Data Release (DR3) p…
On the ages of bright galaxies 500 Myr after the big bang: insights into star formation activity at z ≳ 15 with JWST
Charlot, Stéphane; Chen, Zuyi; Stark, Daniel P. +3 more
With JWST, new opportunities to study the evolution of galaxies in the early Universe are emerging. Spitzer constraints on rest-optical properties of z ≳ 7 galaxies demonstrated the power of using galaxy stellar masses and star formation histories (SFHs) to indirectly infer the cosmic star formation history. However, only the brightest individual …