Search Publications
The Origin of Dust Polarization in the Orion Bar
Soam, Archana; Hoang, Thiem; Le Gouellec, Valentin J. M. +8 more
The linear polarization of thermal dust emission provides a powerful tool to probe interstellar and circumstellar magnetic fields, because aspherical grains tend to align themselves with magnetic field lines. While the Radiative Alignment Torque (RAT) mechanism provides a theoretical framework for this phenomenon, some aspects of this alignment me…
Probability Distribution Functions of Sunspot Magnetic Flux
Toriumi, Shin; Sakurai, Takashi
We investigated the probability distributions of sunspot area and magnetic flux by using data from the Royal Greenwich Observatory and USAF/NOAA. We constructed a sample of 2995 regions with maximum-development areas ≥500 MSH (millionths of solar hemisphere), covering 146.7 yr (1874-2020). The data were fitted by a power-law distribution and four …
Harnessing the Hubble Space Telescope Archives: A Catalog of 21,926 Interacting Galaxies
Mantha, Kameswara Bharadwaj; Simmons, Brooke D.; Merín, Bruno +13 more
Mergers play a complex role in galaxy formation and evolution. Continuing to improve our understanding of these systems requires ever larger samples, which can be difficult (even impossible) to select from individual surveys. We use the new platform ESA Datalabs to assemble a catalog of interacting galaxies from the Hubble Space Telescope science …
Morphology of Star-forming Clumps in Ram-pressure Stripped Galaxies as Seen by HST
Scarlata, Claudia; Calzetti, Daniela; Vulcani, Benedetta +9 more
We characterize the morphological properties of a statistically relevant sample of Hα and UV young star-forming clumps and optical complexes, observed with the Hubble Space Telescope in six galaxies of the GASP sample undergoing ram pressure stripping. The catalogs comprise 2406 (323 in the tails) Hα clumps, 3750 (899) UV clumps, and 424 tail opti…
HH 80/81: Structure and Kinematics of the Fastest Protostellar Outflow
Bally, John; Reipurth, Bo
Hubble Space Telescope (HST) images obtained in 2018 are combined with archival HST data taken in 1995 to detect changes and measure proper motions in the HH 80/81 shock complex, which is powered by the fastest known jet driven by a forming star, the massive object IRAS 18162-2048. Some persistent features close to the radio jet axis have proper m…
Variability of Magnetic Hot Stars from the TESS Observations
Li, Gang; Zhang, Yu; Fu, Jian-Ning +7 more
Magnetic hot stars refer to stars that have effective temperatures approximately in the range from 7000-50,000 K, and with large-scale globally organized magnetic fields. These magnetic fields exhibit strengths ranging from tens of Gauss to tens of kilo-Gauss. They are key in understanding the effects caused by magnetic fields in the stellar evolu…
Caught in the Act: A Metal-rich High-velocity Cloud in the Inner Galaxy
Jenkins, Edward B.; Fox, Andrew J.; Wakker, Bart P. +7 more
We characterize the chemical and physical conditions in an outflowing high-velocity cloud (HVC) in the inner Galaxy. We report a supersolar metallicity of [O/H] = +0.36 ± 0.12 for the HVC at v LSR = 125.6 km s-1 toward the star HD 156359 (l = 328.°7, b = -14.°5, d = 9 kpc, z = -2.3 kpc). Using archival observations from the F…
The Mass of the Black Hole in NGC 5273 from Stellar Dynamical Modeling
Vasiliev, Eugene; Onken, Christopher A.; Bentz, Misty C. +2 more
We present a new constraint on the mass of the black hole in the active S0 galaxy NGC 5273. Due to the proximity of the galaxy at 16.6 ± 2.1 Mpc, we were able to resolve and extract the bulk motions of stars near the central black hole using adaptive-optics-assisted observations with the Gemini Near-infrared Integral Field Spectrograph, as well as…
The Apparent Absence of Forward Scattering in the HD 53143 Debris Disk
Stark, Christopher C.; MacGregor, Meredith A.; Weinberger, Alycia J. +5 more
HD 53143 is a mature Sun-like star and host to a broad disk of dusty debris, including a cold outer ring of planetesimals near 90 au. Unlike most other inclined debris disks imaged at visible wavelengths, the cold disk around HD 53143 appears as disconnected "arcs" of material, with no forward-scattering side detected to date. We present new, deep…
The Clustering Properties of AGNs/Quasars in CatWISE2020 Catalog
Tiwari, Prabhakar; Zhao, Gong-Bo; Nusser, Adi
We study the clustering properties of 1,307,530 AGNs/quasars in the CatWISE2020 catalog prepared using the Wide-field Infrared Survey Explorer and Near-Earth Object Wide-field Infrared Survey Explorer survey data. For angular moments ℓ ⪆ 10 (⪅18°) down to nonlinear scales, the results are in agreement with the standard ΛCDM cosmology, with a galax…