Search Publications
The Parallax Zero-point of Gaia Early Data Release 3 from LAMOST Primary Red Clump Stars
Huang, Yang; Beers, Timothy C.; Yuan, Haibo +1 more
We present an independent examination of the parallax zero-point of the Third Gaia Early Data Release (hereafter EDR3), using the LAMOST primary red clump (PRC) stellar sample. A median parallax offset of around 26 µas, slightly larger than that found by examination of distant quasars, is found for both the five- and six-parameter solutions …
The TW Hya Rosetta Stone Project. III. Resolving the Gaseous Thermal Profile of the Disk
Zhang, Ke; Öberg, Karin; Walsh, Catherine +16 more
The thermal structure of protoplanetary disks is a fundamental characteristic of the system that has wide-reaching effects on disk evolution and planet formation. In this study, we constrain the 2D thermal structure of the protoplanetary disk TW Hya structure utilizing images of seven CO lines. This includes new ALMA observations of 12C…
The Magnetic Origin of Solar Campfires
Tiwari, Sanjiv K.; Cheung, Mark C. M.; Berghmans, David +4 more
Solar campfires are fine-scale heating events, recently observed by Extreme Ultraviolet Imager (EUI) on board Solar Orbiter. Here we use EUI 174 Å images, together with EUV images from Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA), and line-of-sight magnetograms from SDO/Helioseismic and Magnetic Imager (HMI) to investigate t…
Evidence of a Dwarf Galaxy Stream Populating the Inner Milky Way Halo
Malhan, Khyati; Ibata, Rodrigo A.; Martin, Nicolas F. +3 more
Stellar streams produced from dwarf galaxies provide direct evidence of the hierarchical formation of the Milky Way. Here, we present the first comprehensive study of the LMS-1 stellar stream, that we detect by searching for wide streams in the Gaia EDR3 data set using the STREAMFINDER algorithm. This stream was recently discovered by Yuan et al. …
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 …