Search Publications
Enhanced Localization of Transients Based on a Novel Cross-correlation Method
Huang, Y.; Zhang, S. N.; Zhao, Y. +12 more
Locating gamma-ray transients including gamma-ray bursts (GRBs) and soft gamma repeater (SGR) bursts is of great importance in multi-messenger and multi-wavelength astronomy, such as guiding optical and radio follow-up observations and evaluating the association of a GRB with a gravitational wave or an SGR with a galaxy or fast radio burst (FRB). …
Systematic Study of Acceleration Efficiency in Young Supernova Remnants with Nonthermal X-Ray Observations
Uchiyama, Yasunobu; Aharonian, Felix; Khangulyan, Dmitry +1 more
Cutoff energy in a synchrotron radiation spectrum of a supernova remnant (SNR) contains a key parameter of ongoing particle acceleration. We systematically analyze 11 young SNRs, including all historical SNRs, to measure the cutoff energy, thus shedding light on the nature of particle acceleration at the early stage of SNR evolution. The nontherma…
The Remnant and Origin of the Historical Supernova 1181 AD
Parker, Quentin A.; Ritter, Andreas; Guerrero, Martín A. +3 more
The guest star of AD 1181 is the only historical supernova of the past millennium that is without a definite counterpart. The previously proposed association with supernova remnant G130.7+3.1 (3C 58) is in strong doubt because of the inferred age of this remnant. Here we report a new identification of SN 1181 with our codiscovery of the hottest kn…
The Architecture of the V892 Tau System: The Binary and Its Circumbinary Disk
Henning, Thomas; Wilner, David J.; Kwon, Woojin +11 more
We present high-resolution millimeter continuum and CO line observations for the circumbinary disk around V892 Tau to constrain the stellar and disk properties. The total mass of the two near-equal-mass A stars is estimated to be 6.0 ± 0.2 M⊙ based on our models of the Keplerian-dominated gas disk rotation. The detection of strong ioniz…
NICER Detection of Thermal X-Ray Pulsations from the Massive Millisecond Pulsars PSR J0740+6620 and PSR J1614-2230
Bogdanov, Slavko; Ray, Paul S.; Wolff, Michael T. +11 more
We report the detection of X-ray pulsations from the rotation-powered millisecond-period pulsars PSR J0740+6620 and PSR J1614-2230, two of the most massive neutron stars known, using observations with the Neutron Star Interior Composition Explorer (NICER). We also analyze X-ray Multi-Mirror Mission (XMM-Newton) data for both pulsars to obtain thei…
Filament Rotation in the California L1482 Cloud
Klessen, R. S.; Stutz, A. M.; Law, C. Y. +5 more
We analyze the gas mass distribution, the gas kinematics, and the young stellar objects of the California Molecular Cloud L1482 filament. The mean Gaia DR2 YSO distance is ${511}_{-16}^{+17}$ pc. In terms of the gas, the line-mass (M/L) profiles are symmetric scale-free power laws consistent with cylindrical geometry. We calculate the gravitationa…
Ancient Very Metal-poor Stars Associated with the Galactic Disk in the H3 Survey
Conroy, Charlie; Ting, Yuan-Sen; Cargile, Phillip A. +8 more
Ancient, very metal-poor (VMP) stars offer a window into the earliest epochs of galaxy formation and assembly. We combine data from the H3 Spectroscopic Survey and Gaia to measure metallicities, abundances of α elements, stellar ages, and orbital properties of a sample of 482 VMP ([Fe/H] < -2) stars in order to constrain their origins. This sam…
ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): Detection of Extremely High-density Compact Structure of Prestellar Cores and Multiple Substructures Within
Sanhueza, Patricio; Kwon, Woojin; Soam, Archana +38 more
Prestellar cores are self-gravitating dense and cold structures within molecular clouds where future stars are born. They are expected, at the stage of transitioning to the protostellar phase, to harbor centrally concentrated dense (sub)structures that will seed the formation of a new star or the binary/multiple stellar systems. Characterizing thi…
An ALMA Gas-dynamical Mass Measurement of the Supermassive Black Hole in the Local Compact Galaxy UGC 2698
Ho, Luis C.; Gebhardt, Karl; Barth, Aaron J. +9 more
We present 0"14 resolution Atacama Large Millimeter/submillimeter Array (ALMA) CO(2-1) observations of the circumnuclear gas disk in UGC 2698, a local compact galaxy. The disk exhibits regular rotation with projected velocities rising to 450 km s-1 near the galaxy center. We fit gas-dynamical models to the ALMA data cube, assuming the C…
Correction to the Photometric Colors of the Gaia Data Release 2 with the Stellar Color Regression Method
Niu, Zexi; Liu, Jifeng; Yuan, Haibo
The second Gaia data release (DR2) delivers accurate and homogeneous photometry data of the whole sky of an exquisite quality, reaching down to the unprecedented millimagnitude (mmag) level for the G, GRP, and GBP passbands. However, the presence of magnitude-dependent systematic effects at the 10 mmag level limits its power …