Search Publications
NICER/NuSTAR Characterization of 4U 1957+11: A Near Maximally Spinning Black Hole Potentially in the Mass Gap
Steiner, James F.; Remillard, Ronald A.; Grinberg, Victoria +5 more
4U 1957+11 is a black hole candidate system that has been in a soft X-ray spectral state since its discovery. We present analyses of recent joint NICER and NuSTAR spectra, which are extremely well described by a highly inclined disk accreting into a near maximally spinning black hole. Owing to the broad X-ray coverage of NuSTAR, the fitted spin an…
No Surviving SN Ia Companion in SNR 0509-67.5: Stellar Population Characterization and Comparison to Models
Hughes, John P.; Shields, Joshua V.; Kerzendorf, Wolfgang +4 more
The community agrees that Type Ia supernovae arise from carbon/oxygen white dwarfs undergoing thermonuclear runaway. However, the full progenitor system and the process that prompts the white dwarf to explode remain unknown. Most current models suggest that the white dwarf explodes because of interaction with a binary companion that may survive th…
An X-Ray Census of Fast Radio Burst Host Galaxies: Constraints on Active Galactic Nuclei and X-Ray Counterparts
Tejos, N.; Dong, Y.; Fong, W. +16 more
We present the first X-ray census of fast radio burst (FRB) host galaxies to conduct the deepest search for active galactic nuclei (AGN) and X-ray counterparts to date. Our sample includes seven well-localized FRBs with unambiguous host associations and existing deep Chandra observations, including two events for which we present new observations.…
Weighing the Darkness. II. Astrometric Measurement of Partial Orbits with Gaia
Breivik, Katelyn; Andrews, Jeff J.; Chawla, Chirag +2 more
Over the course of several years, stars trace helical trajectories as they traverse across the sky due to the combined effects of proper motion and parallax. It is well known that the gravitational pull of an unseen companion can cause deviations to these tracks. Several studies have pointed out that the astrometric mission Gaia will be able to id…
First BISTRO Observations of the Dark Cloud Taurus L1495A-B10: The Role of the Magnetic Field in the Earliest Stages of Low-mass Star Formation
Zhang, Yapeng; Pattle, Kate; Karoly, Janik +155 more
We present BISTRO Survey 850 µm dust emission polarization observations of the L1495A-B10 region of the Taurus molecular cloud, taken at the James Clerk Maxwell Telescope (JCMT). We observe a roughly triangular network of dense filaments. We detect nine of the dense starless cores embedded within these filaments in polarization, finding that…
The Subtle Effects of Mergers on Star Formation in Nearby Galaxies
Ho, Luis C.; Shangguan, Jinyi; Li, Yang A.
Interactions and mergers play an important role in regulating the physical properties of galaxies, such as their morphology, gas content, and star formation rate (SFR). Controversy exists as to the degree to which these events, even gas-rich major mergers, enhance star formation activity. We study merger pairs selected from a sample of massive (M …
First Infrared Coronal Spectra from DKIST/Cryo-NIRSP: Comparisons with Global MHD Models
Tritschler, Alexandra; Schad, Thomas A.; Kuhn, Jeffrey R. +4 more
The Cryogenic Near-Infrared Spectropolarimeter (Cryo-NIRSP) is now conducting science operations at the National Science Foundation's Daniel K. Inouye Solar Telescope (DKIST). We report results obtained during instrument commissioning that advance multiwavelength coronagraphic observations in the infrared. This includes the first observations of t…
A Study of Stellar Spins in 15 Open Clusters
Schlaufman, Kevin C.; Healy, Brian F.; McCullough, P. R. +1 more
We analyze spectroscopic and photometric data to determine the projected inclinations of stars in 11 open clusters, placing constraints on the spin-axis distributions of six clusters. We combine these results with four additional clusters studied by Healy & McCullough and Healy et al. to perform an ensemble analysis of their spins. We find tha…
The Evaporating Massive Embedded Stellar Cluster IRS 13 Close to Sgr A*. I. Detection of a Rich Population of Dusty Objects in the IRS 13 Cluster
Eckart, Andreas; Zajaček, Michal; Labadie, Lucas +6 more
A detailed analysis of the nuclear star cluster not only concedes the existence of the S cluster, with its fast-moving stars and the supermassive black hole Sgr A*. It also reveals an embedded region of gas and dust with an exceptionally high stellar density called IRS 13. The IRS 13 cluster can be divided into the northern and eastern counterpart…
ALMA Measurement of 10 kpc Scale Lensing-power Spectra toward the Lensed Quasar MG J0414+0534
Matsushita, Satoki; Minezaki, Takeo; Nakanishi, Kouichiro +1 more
The lensing power spectra for gravitational potential, astrometric shift, and convergence perturbations are powerful probes to investigate dark matter structures on small scales. We report the first lower and upper bounds of these lensing power spectra on angular scale ~1″ toward the anomalous quadruply lensed quasar MG J0414+0534 at a redshift z …