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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…
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…
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…
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…
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…
Wide binaries from the H3 survey: the thick disk and halo have similar wide binary fractions
Hsiang-Chih Hwang, Yuan-Sen Ting, Charlie Conroy +8
Due to the different environments in the Milky Way's disk and halo, comparing wide binaries in the disk and halo is key to understanding wide binary formation and evolution. By usi…
A hidden population of high-redshift double quasars unveiled by astrometry
Yue Shen, Yu-Ching Chen, Hsiang-Chih Hwang +6
Galaxy mergers occur frequently in the early universe and bring multiple supermassive black holes (SMBHs) into the nucleus, where they may eventually coalesce. Identifying post-mer…
Evidence for the Accretion of Gas in Star-Forming Galaxies: High N/O Abundances in Regions of Anomalously-Low Metallicity
Yuanze Luo, Timothy Heckman, Hsiang-Chih Hwang +11
While all models for the evolution of galaxies require the accretion of gas to sustain their growth via on-going star formation, it has proven difficult to directly detect this inf…
Varstrometry for Off-nucleus and Dual sub-Kpc AGN (VODKA): How Well-centered Are Low-z AGN?
Yue Shen, Hsiang-Chih Hwang, Nadia Zakamska +1
Off-nucleus active galactic nuclei (AGN) can be signposts of inspiraling supermassive black holes (SMBHs) on galactic scales, or accreting SMBHs recoiling after the coalescence of…
Varstrometry for Off-nucleus and Dual sub-Kpc AGN (VODKA): Methodology and Initial Results with Gaia DR2
Hsiang-Chih Hwang, Yue Shen, Nadia Zakamska +1
Gaia's milli-arcsec (mas) astrometric precision allows systematic identification of optically-selected sub-kpc dual active galactic nuclei (AGN), off-nucleus AGN, and small-scale l…
A Pseudodisk Threaded with a Toroidal and Pinched Poloidal Magnetic Field Morphology in the HH 211 Protostellar System
Chin-Fei Lee, Woojin Kwon, Kai-Syun Jhan +6
The HH 211 protostellar system is currently the youngest Class 0 system found with a rotating disk. We have mapped it at ~ 50 au (0.16") resolution, studying its magnetic field mor…
Characterizing the local relation between star formation rate and gas-phase metallicity in MaNGA spiral galaxies
Laura Sánchez-Menguiano, Jorge Sánchez Almeida, Casiana Muñoz-Tuñón +4
The role of gas accretion in galaxy evolution is still a matter of debate. The presence of inflows of metal-poor gas that trigger star formation bursts of low metallicity has been…
Anomalously low metallicity regions in MaNGA star-forming galaxies: Accretion Caught in Action?
Hsiang-Chih Hwang, Jorge K. Barrera-Ballesteros, Timothy M. Heckman +14
We use data from 1222 late-type star-forming galaxies in the SDSS IV MaNGA survey to identify regions in which the gas-phase metallicity is anomalously-low compared to expectations…
SDSS-IV MaNGA: Spatially resolved star-formation histories and the connection to galaxy physical properties
K. Rowlands, T. Heckman, V. Wild +11
A key task of observational extragalactic astronomy is to determine where -- within galaxies of diverse masses and morphologies -- stellar mass growth occurs, how it depends on gal…
Winds as the origin of radio emission in radio-quiet extremely red quasars
Hsiang-Chih Hwang, Nadia L. Zakamska, Rachael M. Alexandroff +4
Most active galactic nuclei (AGNs) are radio-quiet, and the origin of their radio emission is not well-understood. One hypothesis is that this radio emission is a by-product of qua…
Angular momentum loss in the envelope-disk transition region of HH 111 protostellar system: evidence for magnetic braking?
Chin-Fei Lee, Hsiang-Chih Hwang, Zhi-Yun Li
HH 111 is a Class I protostellar system at a distance of ~ 400 pc, with the central source VLA 1 associated with a rotating disk deeply embedded in a flattened envelope. Here we pr…
Magnetic field structure in the Flattened Envelope and Jet in the young protostellar system HH 211
Chin-Fei Lee, Ramprasad Rao, Tao-Chung Ching +4
HH 211 is a young Class 0 protostellar system, with a flattened envelope, a possible rotating disk, and a collimated jet. We have mapped it with the Submillimeter Array in 341.6 GH…