Search Publications
Looking at the Distant Universe with the MeerKAT Array: Discovery of a Luminous OH Megamaser at z > 0.5
Holwerda, Benne W.; Ravindranath, Swara; Somerville, Rachel S. +65 more
In the local universe, OH megamasers (OHMs) are detected almost exclusively in infrared-luminous galaxies, with a prevalence that increases with IR luminosity, suggesting that they trace gas-rich galaxy mergers. Given the proximity of the rest frequencies of OH and the hyperfine transition of neutral atomic hydrogen (H I), radio surveys to probe t…
Role of Longitudinal Waves in Alfvén-wave-driven Solar Wind
Shoda, Munehito; Shimizu, Kimihiko; Suzuki, Takeru K.
We revisit the role of longitudinal waves in driving the solar wind. We study how the p-mode-like vertical oscillation on the photosphere affects the properties of solar winds in the framework of Alfvén-wave-driven winds. We perform a series of one-dimensional magnetohydrodynamical numerical simulations from the photosphere to beyond several tens …
The Second AGILE MCAL Gamma-Ray Burst Catalog: 13 yr of Observations
Longo, F.; Morselli, A.; Chen, A. +20 more
We present the results of a systematic search and analysis of GRBs detected by the Astrorivelatore Gamma ad Immagini LEggero (AGILE) MiniCALorimeter (MCAL; 0.4-100 MeV) over a time frame of 13 yr, from 2007 to 2020 November. The MCAL GRB sample consists of 503 bursts triggered by MCAL, 394 of which were fully detected onboard with high time resolu…
Conditions for Proton Temperature Anisotropy to Drive Instabilities in the Solar Wind
Verscharen, Daniel; Chen, Christopher H. K.; Opie, Simon +2 more
Using high-resolution data from Solar Orbiter, we investigate the plasma conditions necessary for the proton temperature-anisotropy-driven mirror-mode and oblique firehose instabilities to occur in the solar wind. We find that the unstable plasma exhibits dependencies on the angle between the direction of the magnetic field and the bulk solar wind…
Dramatic Changes in the Observed Velocity of the Accretion Disk Wind in MCG-03-58-007 Are Revealed by XMM-Newton and NuSTAR
Ballo, L.; Reeves, J. N.; Braito, V. +6 more
Past X-ray observations of the nearby Seyfert 2 MCG-03-58-007 revealed the presence of a powerful and highly variable disk wind, where two possible phases outflowing with v out1/c ~ -0.07 and v out2/c ~ -0.2 were observed. Multi-epoch X-ray observations, covering the period from 2010 to 2018, showed that the lower-velocity co…
Hubble Space Telescope Imaging of Isolated Local Volume Dwarfs GALFA Dw3 and Dw4
Crnojević, D.; Mutlu-Pakdil, B.; Sand, D. J. +16 more
We present observations of the dwarf galaxies GALFA Dw3 and GALFA Dw4 with the Advanced Camera for Surveys on the Hubble Space Telescope. These galaxies were initially discovered as optical counterparts to compact H I clouds in the GALFA survey. Both objects resolve into stellar populations which display old red giant branch (RGB), younger helium-…
Galactic Winds across the Gas-rich Merger Sequence. I. Highly Ionized N V and O VI Outflows in the QUEST Quasars
Maiolino, Roberto; Tripp, Todd M.; Hamann, Fred +12 more
This program is part of QUEST (Quasar/ULIRG Evolutionary Study) and seeks to examine the gaseous environments of z ≲ 0.3 quasars and ULIRGs as a function of host galaxy properties and age across the merger sequence from ULIRGs to quasars. This first paper in the series focuses on 33 quasars from the QUEST sample and on the kinematics of the highly…
ALMA Discovery of a Disk around the Planetary-mass Companion SR 12 c
Kraus, Adam L.; Bowler, Brendan P.; Zhu, Zhaohuan +6 more
We report an Atacama Large Millimeter/submillimeter Array 0.88 mm (Band 7) continuum detection of the accretion disk around SR 12 c, an ~11 M Jup planetary-mass companion (PMC) orbiting its host binary at 980 au. This is the first submillimeter detection of a circumplanetary disk around a wide PMC. The disk has a flux density of 127 ± 1…
An Assessment of the In Situ Growth of the Intracluster Light in the High-redshift Galaxy Cluster SpARCS1049+56
Muzzin, Adam; Yee, H. K. C.; Perlmutter, Saul +11 more
The formation of the stellar mass within galaxy cluster cores is a poorly understood process. It features the complicated physics of cooling flows, active galactic nucleus feedback, star formation, and more. Here we study the growth of the stellar mass in the vicinity of the brightest cluster galaxy (BCG) in a z = 1.7 cluster, SpARCS1049+56. We sy…
Hubble Space Telescope Imaging Reveals That SN 2015bh Is Much Fainter than Its Progenitor
Smith, Nathan; Strader, Jay; Sand, David J. +5 more
We present Hubble Space Telescope (HST) imaging of the site of SN 2015bh in the nearby spiral galaxy NGC 2770 taken between 2017 and 2019, nearly four years after the peak of the explosion. In 2017-2018, the transient fades steadily in optical filters before declining more slowly to F814W = -7.1 mag in 2019, ≈4 mag below the level of its eruptive …