Search Publications
Dynamical Evolution of White Dwarfs in Triples in the Era of Gaia
Angelo, Isabel; Naoz, Smadar; Hansen, Bradley M. S. +3 more
The Gaia mission has detected many white dwarfs (WDs) in binary and triple configurations, and while observations suggest that triple-stellar systems are common in our Galaxy, not much attention was devoted to WDs in triples. For stability reasons, these triples must have hierarchical configurations, i.e., two stars are on a tight orbit (the inner…
Evidence for a Massive Andromeda Galaxy Using Satellite Galaxy Proper Motions
Patel, Ekta; Mandel, Kaisey S.
We present new mass estimates for Andromeda (M31) using the orbital angular momenta of four satellite galaxies (M33, NGC 185, NGC 147, and IC 10) derived from existing proper motions, distances, and line-of-sight velocities. We infer two masses for M31: ${M}_{\mathrm{vir}}={2.85}_{-0.77}^{+1.47}\times {10}^{12}\,{M}_{\odot }$ using satellite galax…
Fast Radio Bursts as Probes of Magnetic Fields in Galaxies at z < 0.5
Simha, Sunil; Prochaska, J. Xavier; Rafelski, Marc +6 more
We present a sample of nine fast radio bursts (FRBs) from which we derive magnetic field strengths of the host galaxies represented by normal, z < 0.5 star-forming galaxies with stellar masses M * ≈ 108-1010.5 M ⊙. We find no correlation between the FRB rotation measure (RM) and redshift, which indica…
Reconstructing the Assembly of Massive Galaxies. II. Galaxies Develop Massive and Dense Stellar Cores as They Evolve and Head toward Quiescence at Cosmic Noon
Giavalisco, Mauro; Ji, Zhiyuan
We use the spectral energy distribution fitting code PROSPECTOR to reconstruct the nonparametric star formation history (SFH) of massive ( $\mathrm{log}{M}_{* }\gt 10.3$ ) star-forming galaxies (SFGs) and quiescent galaxies (QGs) at redshift z obs ~ 2 to investigate the joint evolution of star formation activity and structural propertie…
JWST-TST Proper Motions. I. High-precision NIRISS Calibration and Large Magellanic Cloud Kinematics
Anderson, Jay; Stevenson, Kevin B.; MacDonald, Ryan J. +27 more
We develop and disseminate effective point-spread functions and geometric-distortion solutions for high-precision astrometry and photometry with the JWST NIRISS instrument. We correct field dependencies and detector effects, and assess the quality and the temporal stability of the calibrations. As a scientific application and validation, we study …
Star Formation and Molecular Gas Diagnostics with Mid- and Far-infrared Emission
Leroy, A.; Smith, J. -D. T.; Sandstrom, K. +1 more
With the start of JWST observations, mid-infrared (MIR) emission features from polycyclic aromatic hydrocarbons (PAHs), H2 rotational lines, fine structure lines from ions, and dust continuum will be widely available tracers of gas and star formation rate (SFR) in galaxies at various redshifts. Many of these tracers originate from dust …
Photochemical Hazes Dramatically Alter Temperature Structure and Atmospheric Circulation in 3D Simulations of Hot Jupiters
Kreidberg, Laura; Parmentier, Vivien; Zhang, Xi +5 more
Photochemical hazes are expected to form in hot Jupiter atmospheres and may explain the strong scattering slopes and muted spectral features observed in the transmission spectra of many hot Jupiters. Absorption and scattering by photochemical hazes have the potential to drastically alter temperature structure and atmospheric circulation of these p…
Nature and Nurture? Comparing Lyα Detections in UV-bright and Fainter [O III]+Hβ Emitters at z 8 with Keck/MOSFIRE
Santini, Paola; Fontana, Adriano; Treu, Tommaso +7 more
The 100% detection rate of Lyα emission in a sample of four luminous z ~ 8 galaxies with red Spitzer/IRAC colors suggests objects with unusual ionizing capabilities that created early ionized bubbles in a neutral era. Whether such bubbles reflect enhanced ionizing properties (nature) or an overdense environment (nurture), however, remains unclear.…
JWST's PEARLS: Bright 1.5-2.0 µm Dropouts in the Spitzer/IRAC Dark Field
Grogin, Norman A.; Hathi, Nimish P.; Pirzkal, Nor +35 more
Using the first epoch of four-band NIRCam observations obtained by the James Webb Space Telescope (JWST) Prime Extragalactic Areas for Reionization and Lensing Science Program in the Spitzer IRAC Dark Field, we search for F150W and F200W dropouts. In 14.2 arcmin2, we have found eight F150W dropouts and eight F200W dropouts, all brighter…
A High-resolution Optical Survey of Upper Sco: Evidence for Coevolution of Accretion and Disk Winds
Fang, Min; Pascucci, Ilaria; Edwards, Suzan +3 more
Magnetohydrodynamic (MHD) and photoevaporative winds are thought to play an important role in the evolution and dispersal of planet-forming disks. Here, we analyze high-resolution (Δv ~ 7 km s-1) optical spectra from a sample of 115 T Tauri stars in the ~5-10 Myr Upper Sco association and focus on the [O I] λ6300 and Hα lines to trace d…