Search Publications
HCN and HCO+ in Planetary Nebulae: The Next Level
Ziurys, L. M.; Schmidt, D. R.; Gold, K. R. +2 more
Observations of HCN and HCO+ have been carried out toward 13 planetary nebulae (PNe) using the facilities of the Arizona Radio Observatory (ARO). These nebulae represent a wide range of morphologies and ages (~2000-28,000 yr). For both molecules, the J = 1 → 0 transitions at 88-89 GHz and the J = 3 → 2 lines at 265-267 GHz were measured…
Pulse Timing Discovery of a Three-day Companion to the Hot Subdwarf BPM 36430
Hermes, J. J.; Barlow, Brad N.; Schaffenroth, Veronika +2 more
Hot subdwarf B stars are core-helium-burning objects that have undergone envelope stripping, likely by a binary companion. Using high-speed photometry from the Transiting Exoplanet Survey Satellite, we have discovered the hot subdwarf BPM 36430 is a hybrid sdBVrs pulsator exhibiting several low-amplitude g-modes and a strong p-mode puls…
An EUV Jet Driven by a Series of Transition Region Microjets
Fu, Hui; Xia, Lidong; Huang, Zhenghua +5 more
Jets are one of the most common eruptive events in the solar atmosphere, and they are believed to be important in the context of coronal heating and solar wind acceleration. We present an observational study on a sequence of jets with the data acquired with the Solar Dynamics Observatory and the Interface Region Imaging Spectrograph. This sequence…
The Ages of Optically Bright Subclusters in the Serpens Star-forming Region
Fang, Min; Herczeg, Gregory J.; Liu, Yao +2 more
The Serpens Molecular Cloud is one of the most active star-forming regions within 500 pc, with over 1000 young stellar objects (YSOs) at different evolutionary stages. The ages of the member stars inform us about the star formation history of the cloud. In this paper, we develop a spectral energy distribution (SED) fitting method for nearby evolve…
Optical Studies of 10 Hard X-Ray-selected Cataclysmic Binaries
Thorstensen, John R.; Halpern, Jules P.
We conducted time-resolved optical spectroscopy and/or photometry of 10 cataclysmic binaries that were discovered in hard X-ray surveys, with the goal of measuring their orbital periods and searching for evidence that they are magnetic. Four of the objects in this study are new optical identifications: IGR J18017-3542, PBC J1841.1+0138, IGR J18434…
Discrepancy between the Low-frequency Cutoffs of Type III Radio Bursts Based on Simultaneous Observations by WIND and PSP
Bale, Stuart D.; Pulupa, Marc; Wu, Dejin +2 more
The cutoff frequency is an important characteristic parameter of type III radio bursts. Employing the radio data of the Parker Solar Probe (PSP) in the encounter phases of its first five orbits, our previous work revealed that the maximum probability distribution of the cutoff frequency f lo (~680 kHz) is remarkably higher than that b…
The Central 300 pc of the Galaxy Probed by Infrared Spectra of H3 + and CO. III. Locations of Sgr B2 and Star Iota
Geballe, T. R.; Oka, Takeshi
Using a simple relation between the radial expansion velocity of diffuse gas in the Central Molecular Zone (CMZ) of the Galaxy and its distance from Sgr A* we estimate the physical depths within the CMZ of Star ι (2MASS J17470898-2829561) and two Sgr B2 far-infrared continuum sources with respect to the location of Sgr A*. To do this we…
Revisiting the Circumnuclear X-Ray Emission of NGC 2992 in a Historically Low State
Wang, Junfeng; Xu, Xiaoyu
The innermost region of the Seyfert galaxy NGC 2992 has long been suspected to be the location of intense AGN-host galaxy interaction, but photon pile up in previous high-resolution observations hampered the study of the soft X-ray excess and the interaction near its nucleus. We present an X-ray imaging and spectroscopic analysis of the circumnucl…
Numerical Modeling of Suprathermal Electron Transport in the Solar Wind: Effects of Whistler Turbulence with a Full Diffusion Tensor
Zank, Gary P.; Tang, Bofeng; Kolobov, Vladimir I.
The electron VDF in the solar wind consists of a Maxwellian core, a suprathermal halo, a field-aligned component strahl, and an energetic superhalo that deviates from the equilibrium. Whistler wave turbulence is thought to resonantly scatter the observed electron velocity distribution. Wave-particle interactions that contribute to Whistler wave tu…
Expediting DECam Multimessenger Counterpart Searches with Convolutional Neural Networks
Bechtol, K.; García-Bellido, J.; Soares-Santos, M. +11 more
Searches for counterparts to multimessenger events with optical imagers use difference imaging to detect new transient sources. However, even with existing artifact-detection algorithms, this process simultaneously returns several classes of false positives: false detections from poor-quality image subtractions, false detections from low signal-to…