70 citations · 1k across the 46 of their papers we have counts for
46 papers
Varstrometry for Off-nucleus and Dual Subkiloparsec AGN (VODKA): Three Quadruply Lensed Quasars at Cosmic Noon in HST and JWST
Mingrui Liu, Yu-Ching Chen, Nadia L. Zakamska +7
We present results from imaging observations of three quadruply lensed quasars by Hubble Space Telescope (HST) and James Webb Space Telescope (JWST) at redshifts , 2.975…
White dwarfs in wide binaries: the strong effects of stellar evolution and mass loss
Hsiang-Chih Hwang, Nadia Zakamska
We examine the statistics of main-sequence / main-sequence, main-sequence / white-dwarf and white-dwarf / white-dwarf wide binaries at 10^2.5-10^4 AU separations in Gaia data. For…
Sloan Digital Sky Survey-V: Pioneering Panoptic Spectroscopy
Juna A. Kollmeier, Hans-Walter Rix, Conny Aerts +217
The Sloan Digital Sky Survey-V (SDSS-V) is pioneering panoptic spectroscopy: it is the first all-sky, multi-epoch, optical-to-infrared spectroscopic survey. SDSS-V is mapping the s…
VODKA: Complex molecular gas dynamics in a kpc-separation z=2.17 dual quasar with ALMA
Yuzo Ishikawa, Nadia L. Zakamska, Yu-Ching Chen +6
In galaxy mergers, dual quasars - two actively accreting supermassive black holes (SMBHs) - provide a unique opportunity to study the interplay between galaxy dynamics and quasar a…
Varstrometry for Off-nucleus and Dual sub-Kpc AGN (VODKA): A Mix of Singles, Lenses, and True Duals at Cosmic Noon
Arran C. Gross, Yu-Ching Chen, Masamune Oguri +8
Dual Active Galactic Nuclei (dual AGNs), a phase in some galaxy mergers during which both central supermassive black holes (SMBHs) are active, are expected to be a key observable s…
Varstrometry for Off-nucleus and Dual sub-Kpc AGN (VODKA): Long-slit optical spectroscopic follow-up with Gemini/GMOS and HST/STIS
Yu-Ching Chen, Arran C. Gross, Xin Liu +4
High spatial and spectral resolution observations are essential for identifying sub-arcsecond dual and lensed quasars and confirming their redshifts. We present Gemini/GMOS and HST…
VODKA-JWST: A 3.8 kpc dual quasar at cosmic noon in a powerful starburst galaxy with JWST/MIRI IFU
Yu-Ching Chen, Yuzo Ishikawa, Nadia L. Zakamska +12
Dual quasars, two active supermassive black holes at galactic scales, represent crucial objects for studying the impact of galaxy mergers and quasar activity on the star formation…
VODKA-JWST: Synchronized growth of two SMBHs in a massive gas disk? A 3.8 kpc separation dual quasar at cosmic noon with NIRSpec IFU
Yuzo Ishikawa, Nadia L. Zakamska, Yue Shen +10
The search for dual supermassive black holes (SMBHs) is of immense interest in modern astrophysics. Galaxy mergers may fuel and produce SMBH pairs. Actively accreting SMBH pairs ar…
Measuring The Mass-Radius Relation of White Dwarfs Using Wide Binaries
Stefan Arseneau, Vedant Chandra, Hsiang-Chih Hwang +10
Measuring the mass-radius relation of individual white dwarfs is an empirically challenging task that has been performed for only a few dozen stars. We measure the white dwarf mass…
Discovery of a Proto-White Dwarf with a Massive Unseen Companion
Gautham Adamane Pallathadka, Vedant Chandra, Nadia L. Zakamska +8
We report the discovery of SDSS~J022932.28+713002.7, a nascent extremely low-mass (ELM) white dwarf (WD) orbiting a massive ( at 2 confidence) companion with a per…
Dynamical masses across the Hertzsprung-Russell diagram
Hsiang-Chih Hwang, Yuan-Sen Ting, Sihao Cheng +1
We infer the dynamical masses of stars across the Hertzsprung-Russell (H-R) diagram using wide binaries from the Gaia survey. Gaia's high-precision astrometry measures the wide bin…
Varstrometry for Off-nucleus and Dual Sub-kpc AGN (VODKA): Very Long Baseline Array Searches for Dual or Off-nucleus Quasars and Small-scale Jets
Yu-Ching Chen, Xin Liu, Joseph Lazio +5
Dual and off-nucleus active supermassive black holes are expected to be common in the hierarchical structure formation paradigm, but their identification at parsec scales remains a…
Discovery and Characterization of Galactic-scale Dual Supermassive Black Holes Across Cosmic Time
Yue Shen, J. Andrew Casey-Clyde, Yu-Ching Chen +10
The hierarchical structure formation paradigm predicts the formation of pairs of supermassive black holes in merging galaxies. When both (or one) members of the SMBH pair are unobs…
Varstrometry for Off-nucleus and Dual sub-Kpc AGN (VODKA): Investigating the Nature of J0823+2418 at : a Likely Lensed Quasar
Arran C. Gross, Yu-Ching Chen, Adi Foord +8
Dual quasars at small physical separations are an important precursor phase of galaxy mergers, ultimately leading to the coalescence of the two supermassive black holes. Starting f…
Varstrometry for Off-nucleus and Dual sub-Kpc AGN (VODKA). SDSS J1608+2716: A Sub-arcsec Quadruply Lensed Quasar at z=2.575
Junyao Li, Xin Liu, Yue Shen +5
We report Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) deep IR (F160W) imaging of SDSS J1608+2716. This system, located at a redshift of z=2.575, was recently reported a…
Cataclysmic Variables from Sloan Digital Sky Survey V -- the search for period bouncers continues
K. Inight, Boris T. Gänsicke, A. Schwope +25
SDSS-V is carrying out a dedicated survey for white dwarfs, single and in binaries, and we report the analysis of the spectroscopy of cataclysmic variables (CVs) and CV candidates…
Wide binary stars formed in the turbulent interstellar medium
Siyao Xu, Hsiang-Chih Hwang, Chris Hamilton +1
The ubiquitous interstellar turbulence regulates star formation and the scaling relations between the initial velocity differences and the initial separations of stars. We propose…
CSS1603+19: a low-mass polar near the cataclysmic variable period minimum
Yiqi Liu, Hsiang-Chih Hwang, Nadia L. Zakamska +1
CSS1603+19 is a cataclysmic variable (CV) with an orbital period of 81.96 min, near the minimal period of cataclysmic variables. It is unusual in having a strong mid-infrared exces…
A close quasar pair in a disk-disk galaxy merger at z = 2.17
Yu-Ching Chen, Xin Liu, Adi Foord +7
Galaxy mergers produce pairs of supermassive black holes (SMBHs), which may be witnessed as dual quasars if both SMBHs are rapidly accreting. The kiloparsec (kpc)-scale separation…
Statistics of Galactic-Scale Quasar Pairs at Cosmic Noon
Yue Shen, Hsiang-Chih Hwang, Masamune Oguri +8
The statistics of galactic-scale quasar pairs can elucidate our understanding of the dynamical evolution of supermassive black hole (SMBH) pairs, the duty cycles of quasar activity…
The mystery in Gaia DR3 triples: occurrence rates, orientations, and eccentricities of wide tertiaries around close binaries
Hsiang-Chih Hwang
The formation of close binaries has been an open question for decades. A large fraction of close binaries are in triple systems, suggesting that their formation may be associated w…
Wide twin binaries are extremely eccentric: evidence of twin binary formation in circumbinary disks
Hsiang-Chih Hwang, Kareem El-Badry, Hans-Walter Rix +3
The Gaia mission recently revealed an excess population of equal-mass "twin" wide binaries, with mass ratio , extending to separations of at least 1000 AU. The origi…
Enhancement of Double-Close-Binary Quadruples
Gavin B. Fezenko, Hsiang-Chih Hwang, Nadia L. Zakamska
Double-close-binary quadruples (2+2 systems) are hierarchical systems of four stars where two short-period binary systems move around their common center of mass on a wider orbit.…
TOI-3714 b and TOI-3629 b: Two gas giants transiting M dwarfs confirmed with HPF and NEID
Caleb I. Cañas, Shubham Kanodia, Chad F. Bender +36
We confirm the planetary nature of two gas giants discovered by TESS to transit M dwarfs. TOI-3714 () is an M2 dwarf hosting a hot Jupiter ($M_p=0.70 \pm 0.03~\ma…