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 …
Effect of temperature on measurement of fundamental constants using white dwarfs in Gaia-EDR3 survey
Uniyal, Akhil; Kalita, Surajit; Chakrabarti, Sayan
Fundamental constants are crucial for comprehending physical mechanisms, but their measurements contain uncertainties due to experimental limitations. We investigate the impact of system temperature on these uncertainties using nearby white dwarfs observed in the Gaia Early Data Release 3 (EDR3) survey. Using the structures of these white dwarfs, …
X-ray detection of the most extreme star-forming galaxies at the cosmic noon via strong lensing
Frye, Brenda L.; Yun, Min S.; Liu, Daizhong +11 more
Hyperluminous infrared galaxies (HyLIRGs) are the most extreme star-forming systems observed in the early Universe, and their properties still elude comprehensive understanding. We have undertaken a large XMM-Newton observing programme to probe the total accreting black hole population in three HyLIRGs at z = 2.12, 3.25, and 3.55, gravitationally …
Particle acceleration at the bow shock of runaway star LS 2355: non-thermal radio emission but no γ-ray counterpart
Motta, S.; van den Eijnden, J.; Mohamed, S. +3 more
Massive stars that travel at supersonic speeds can create bow shocks as their stellar winds interact with the surrounding interstellar medium (ISM). These bow shocks - prominent sites for mechanical feedback of individual massive stars - are predominantly observed in the infrared (IR) band. Confirmed high-energy emission from stellar bow shocks ha…
Unraveling the kinematics of IZw18: A detailed study of ionized gas with MEGARA/GTC
Kehrig, C.; Pérez-Montero, E.; Vílchez, J. M. +6 more
This study offers an in-depth analysis of the kinematic behavior of ionized gas in IZw18, a galaxy notable for its extremely low metallicity and close proximity, utilizing data from MEGARA/GTC. We explored the structure and dynamics of the galaxy through Hα line profiles, applying single and double Gaussian component fittings to create detailed ma…
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…