Search Publications
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…
Pre-main-sequence Brackett Emitters in the APOGEE DR17 Catalog: Line Strengths and Physical Properties of Accretion Columns
Stassun, Keivan G.; Kounkel, Marina; Stringfellow, Guy S. +21 more
Very young (t ≲ 10 Myr) stars possess strong magnetic fields that channel ionized gas from the interiors of their circumstellar disks to the surface of the star. Upon impacting the stellar surface, the shocked gas recombines and emits hydrogen spectral lines. To characterize the density and temperature of the gas within these accretion streams, we…
The Z Camelopardalis-type Star AY Piscium: Stellar and Accretion Disk Parameters
Zharikov, Sergey; Merc, Jaroslav; Kára, Jan +5 more
We present a new study of the Z Cam-type eclipsing cataclysmic variable AY Piscium with the aim of determining the fundamental parameters of the system and the structure of the accretion flow therein. We use time-resolved photometric observations supplemented by spectroscopy in the standstill, to which we applied our light-curve modeling technique…
TREX: Kinematic Characterization of a High-dispersion Intermediate-age Stellar Component in M33
Williams, Benjamin F.; Gilbert, Karoline M.; Guhathakurta, Puragra +7 more
The dwarf galaxy Triangulum (M33) presents an interesting testbed for studying stellar halo formation: it is sufficiently massive so as to have likely accreted smaller satellites, but also lies within the regime where feedback and other "in situ" formation mechanisms are expected to play a role. In this work, we analyze the line-of-sight kinematic…
CWISE J105512.11+544328.3: A Nearby Y Dwarf Spectroscopically Confirmed with Keck/NIRES
Meisner, Aaron M.; Cushing, Michael C.; Kirkpatrick, J. Davy +14 more
Y dwarfs, the coolest known spectral class of brown dwarfs, overlap in mass and temperature with giant exoplanets, providing unique laboratories for studying low-temperature atmospheres. However, only a fraction of Y dwarf candidates have been spectroscopically confirmed. We present Keck/NIRES near-infrared spectroscopy of the nearby (d ≈ 6-8 pc) …
The Black Hole Candidate Swift J1728.9-3613 and the Supernova Remnant G351.9-0.9
Raymond, John; Ray, Paul S.; Zoghbi, Abderahmen +12 more
A number of neutron stars have been observed within the remnants of the core-collapse supernova explosions that created them. In contrast, black holes are not yet clearly associated with supernova remnants (SNRs). Indeed, some observations suggest that black holes are "born in the dark," i.e., without a supernova explosion. Herein, we present a mu…
Multiple Rings and Asymmetric Structures in the Disk of SR 21
Dong, Ruobing; Tamura, Motohide; Liu, Hauyu Baobab +9 more
Crescent-like asymmetric dust structures discovered in protoplanetary disks indicate dust aggregations. Thus, researching these structures helps us understand the planet formation process. Here we analyze ALMA data of the protoplanetary disk around the T-Tauri star SR 21, which has asymmetric structures that were detected in previous submillimeter…
The Initial Mass Function and Other Stellar Properties Across the Core of the Hydra I Cluster
Feldmeier-Krause, A.; Freedman, W. L.; Lonoce, Ilaria
The Hydra I cluster offers an excellent opportunity to study and compare the relic old stellar populations in the core of its two brightest galaxies. In addition, the differing kinematics of the two galaxies allows a test of the local validity of general scaling relations. In this work, we present a direct comparison employing full spectral fittin…