Search Publications
Giant Planets, Tiny Stars: Producing Short-period Planets around White Dwarfs with the Eccentric Kozai-Lidov Mechanism
Gaudi, B. Scott; Naoz, Smadar; Stephan, Alexander P.
The recent discoveries of WD J091405.30+191412.25 (WD J0914 hereafter), a white dwarf (WD) likely accreting material from an ice-giant planet, and WD 1856+534 b (WD 1856 b hereafter), a Jupiter-sized planet transiting a WD, are the first direct evidence of giant planets orbiting WDs. However, for both systems, the observations indicate that the pl…
Zero-metallicity Hypernova Uncovered by an Ultra-metal-poor Star in the Sculptor Dwarf Spheroidal Galaxy
Helmi, Amina; Tolstoy, Eline; Hill, Vanessa +9 more
Although true metal-free "Population III" stars have so far escaped discovery, their nature, and that of their supernovae, is revealed in the chemical products left behind in the next generations of stars. Here we report the detection of an ultra-metal-poor star in the Sculptor dwarf spheroidal galaxy AS0039. With [Fe/H]LTE = -4.11, it …
Evolution of Accretor Stars in Massive Binaries: Broader Implications from Modeling ζ Ophiuchi
Renzo, M.; Götberg, Y.
Most massive stars are born in binaries close enough for mass transfer episodes. These modify the appearance, structure, and future evolution of both stars. We compute the evolution of a 100-day-period binary, consisting initially of a 25 M ⊙ star and a 17 M ⊙ star, which experiences stable mass transfer. We focus on the impa…
Aurora: A Generalized Retrieval Framework for Exoplanetary Transmission Spectra
Madhusudhan, Nikku; Welbanks, Luis
Atmospheric retrievals of exoplanetary transmission spectra provide important constraints on various properties, such as chemical abundances, cloud/haze properties, and characteristic temperatures, at the day-night atmospheric terminator. To date, most spectra have been observed for giant exoplanets due to which retrievals typically assume hydroge…
The Sizes of Quasar Host Galaxies in the Hyper Suprime-Cam Subaru Strategic Program
Schramm, Malte; Strauss, Michael A.; Xue, Yongquan +11 more
The relationship between quasars and their host galaxies provides clues on how supermassive black holes (SMBHs) and massive galaxies are jointly assembled. To elucidate this connection, we measure the structural and photometric properties of the host galaxies of ~5000 Sloan Digital Sky Survey quasars at 0.2 < z < 1 using five-band (grizy) op…
The Carnegie-Chicago Hubble Program. IX. Calibration of the Tip of the Red Giant Branch Method in the Megamaser Host Galaxy, NGC 4258 (M106)
Madore, Barry F.; Freedman, Wendy L.; Beaton, Rachael L. +7 more
In the nearby galaxy NGC 4258, the well-modeled orbital motion of H2O masers about its supermassive black hole provides the means to measure a precise geometric distance. As a result, NGC 4258 is one of a few "geometric anchors" available to calibrate the true luminosities of stellar distance indicators such as the Tip of the Red Giant …
Evaluating Rotation Periods of M Dwarfs across the Ages
Angus, Ruth; Kiman, Rocio; Faherty, Jacqueline K. +5 more
In this work we examine M dwarf rotation rates at a range of ages to establish benchmarks for M dwarf gyrochronology. This work includes a sample of 713 spectroscopically classified M0-M8 dwarfs with new rotation rates measured from K2 light curves. We analyze data and recover rotation rates for 179 of these objects. We add these to rotation rates…
A Dynamical Measurement of the Disk Mass in Elias 227
Testi, Leonardo; Lodato, Giuseppe; Pérez, Laura M. +4 more
Recent multi-wavelength Atacama Large Millimeter/submillimeter Array (ALMA) observations of the protoplanetary disk orbiting around Elias 227 revealed a two-armed spiral structure. The observed morphology, together with the young age of the star and the disk-to-star mass ratio estimated from dust-continuum emission, make this system a perfect labo…
ALMA Lensing Cluster Survey: Bright [C II] 158 µm Lines from a Multiply Imaged Sub-L⋆ Galaxy at z = 6.0719
Ono, Yoshiaki; Ouchi, Masami; Richard, Johan +31 more
We present bright [C II] 158 µm line detections from a strongly magnified and multiply imaged (µ ∼ 20-160) sub-L* ( ${M}_{\mathrm{UV}}=-{19.75}_{-0.44}^{+0.55}$ ) Lyman-break galaxy (LBG) at z = 6.0719 ± 0.0004, drawn from the ALMA Lensing Cluster Survey (ALCS). Emission lines are identified at 268.7 GHz at ≥8σ exactly at th…
The Per-Tau Shell: A Giant Star-forming Spherical Shell Revealed by 3D Dust Observations
Alves, João; Zucker, Catherine; Goodman, Alyssa +6 more
A major question in the field of star formation is how molecular clouds form out of the diffuse interstellar medium (ISM). Recent advances in 3D dust mapping are revolutionizing our view of the structure of the ISM. Using the highest-resolution 3D dust map to date, we explore the structure of a nearby star-forming region, which includes the well-k…