Search Publications
Characterization of Monosubstituted Benzene Ices
Öberg, Karin I.; Piacentino, Elettra L.; Balkanski, Aurelia +1 more
Aromatic structures are fundamental for key biological molecules such as RNA and metabolites and the abundances of aromatic molecules on young planets are therefore of high interest. Recent detections of benzonitrile and other aromatic compounds in interstellar clouds and comets have revealed a rich aromatic astrochemistry. In the cold phases of s…
Nonthermal Observations of a Flare Loop-top Using IRIS Fe XXI: Implications for Turbulence and Electron Acceleration
Polito, Vanessa; Yu, Sijie; Hayes, Laura A. +2 more
The excess broadening of high-temperature spectral lines, long observed near the tops of flare arcades, is widely considered to result from magnetohydrodynamic turbulence. According to different theories, plasma turbulence is also believed to be a candidate mechanism for particle acceleration during solar flares. However, the degree to which this …
Observations of Nonthermal Velocities and Comparisons with an Alfvén Wave Turbulence Model in Solar Active Regions
Hahn, M.; Savin, D. W.; Brooks, D. H. +3 more
We present a study of spectral line width measurements from the Extreme-ultraviolet Imaging Spectrometer on Hinode. We used spectral line profiles of Fe XVI 262.984 Å, Fe XIV 264.787 Å, Fe XIV 270.519 Å, Fe XIV 274.203 Å, and Fe XV 284.160 Å, and studied 11 active regions. Previous studies of spectral line widths have shown that in hot loops in th…
JADES: Spectroscopic Confirmation and Proper Motion for a T-Dwarf at 2 kpc
Carniani, Stefano; D'Eugenio, Francesco; Bunker, Andrew J. +15 more
Large area observations of extragalactic deep fields with the James Webb Space Telescope (JWST) have provided a wealth of candidate low-mass L- and T-class brown dwarfs. The existence of these sources, which are at derived distances of hundreds of parsecs to several kiloparsecs from the Sun, has strong implications for the low-mass end of the stel…
Multiwavelength Observations of Sgr A*. II. 2019 July 21 and 26
Smith, Howard A.; Fazio, Giovanni G.; Bushouse, Howard +6 more
We report on the final two days of a multiwavelength campaign of Sgr A* observing in the radio, submillimeter, infrared (IR), and X-ray bands in 2019 July. Sgr A* was remarkably active, showing multiple flaring events across the electromagnetic spectrum. We detect a transient ∼35 minute periodicity feature in Spitzer light curves on 2019 July 21. …
A Morphokinematic Study of the Enigmatic Emission Nebula NGC 6164/5 Surrounding the Magnetic O-type Star HD 148937
Lim, Beomdu; Nazé, Yaël; Chang, Seok-Jun +1 more
HD 148937 is a peculiar massive star (Of?p) with a strong magnetic field (1 kG). The hourglass-shaped emission nebula NGC 6164/5 surrounds this star. This nebula is presumed to originate from episodic mass-loss events of the central O-type star, but the detailed formation mechanism is not yet well understood. Grasping its three-dimensional structu…
A Complete 16 µm Selected Galaxy Sample at z ∼ 1. II. Morphological Analysis
Cheng, Cheng; Huang, Jia-Sheng; Dai, Y. Sophia +2 more
We present a morphological analysis of the 16 µm flux-density-limited galaxy sample at 0.8 < z < 1.3 from Huang et al. (2021). At the targeted redshift, the 16 µm emission corresponds to the polycyclic aromatic hydrocarbon feature from intense star formation, or dust heated by active galactic nuclei (AGN). Our sample of 479 galax…
Direct Observational Evidence of Multi-epoch Massive Star Formation in G24.47+0.49
Sanhueza, Patricio; Tej, Anandmayee; Hwang, Jihye +19 more
Using new continuum and molecular line data from the Atacama Large Millimeter/submillimeter Array Three-millimeter Observations of Massive Star-forming Regions (ATOMS) survey and archival Very Large Array, 4.86 GHz data, we present direct observational evidence of hierarchical triggering relating three epochs of massive star formation in a ringlik…
Relative Occurrence Rate between Hot and Cold Jupiters as an Indicator to Probe Planet Migration
Fulton, Benjamin J.; Gan, Tianjun; Mao, Shude +4 more
We propose a second-order statistic parameter ɛ, the relative occurrence rate between hot Jupiters (HJs) and cold Jupiters (CJs) (ɛ = η HJ/η CJ), to probe the migration of gas giants. Since the planet occurrence rate is the combined outcome of the formation and migration processes, a joint analysis of HJ and CJ frequency may …
Quasiperiodic Oscillations of Flare Loops and Slipping Motion of Ribbon Substructures during a C-class Flare
Li, Ting; Ye, Jing; Zhang, Yining
Quasiperiodic oscillations in solar-flaring emission have been observed over the past few decades. To date, the underpinning processes resulting in the quasiperiodic oscillations remain unknown. In this paper, we report a unique event that exhibits both the long-duration quasiperiodic intensity oscillations of flare loops and the quasiperiodic sli…