Search Publications
Absorption of Millimeter-band CO and CN in the Early Universe: Molecular Clouds in the Radio Galaxy B2 0902+34 at Redshift 3.4
Lehnert, Matthew D.; Morganti, Raffaella; Villar-Martín, Montserrat +9 more
Using the Karl G. Jansky Very Large Array, we have detected absorption lines due to carbon monoxide, CO(J = 0 → 1), and the cyano radical, CN(N = 0 → 1), associated with radio galaxy B2 0902+34 at redshift z = 3.4. The detection of millimeter-band absorption observed 1.5 Gyr after the Big Bang facilitates studying molecular clouds down to gas mass…
Comparing SCUBA-2 and ALMA Selections of Faint Dusty Star-forming Galaxies in A2744
Barger, A. J.; Cowie, L. L.; McKay, S. J.
We make a comparison of deep SCUBA-2 450 and 850 µm imaging on the massive lensing cluster field A2744 with Atacama Large Millimeter/submillimeter Array (ALMA) 1.2 mm data. Our primary goal is to assess how effective the wider-field SCUBA-2 sample, in combination with red JWST priors, is for finding faint dusty star-forming galaxies (DSFGs) …
An X-Ray Shell Reveals the Supernova Explosion for Galactic Microquasar SS 433
Safi-Harb, Samar; Feng, Hua; Zhou, Ping +5 more
How black holes are formed remains an open and fundamental question in astrophysics. Despite theoretical predictions, it lacks observations to understand whether the black hole formation experiences a supernova explosion. Here we report the discovery of an X-ray shell north of the Galactic microquasar SS 433 harboring a stellar-mass black hole spa…
SAGUARO: Time-domain Infrastructure for the Fourth Gravitational-wave Observing Run and Beyond
Sand, David J.; Fong, Wen-fai; Paterson, Kerry +14 more
We present upgraded infrastructure for Searches After Gravitational waves Using ARizona Observatories (SAGUARO) during LIGO, Virgo, and KAGRA's fourth gravitational-wave (GW) observing run (O4). These upgrades implement many of the lessons we learned after a comprehensive analysis of potential electromagnetic counterparts to the GWs discovered dur…
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…