Search Publications
Origin and Properties of the Near-subsonic Solar Wind Observed by Parker Solar Probe
Liu, Ying D.; Kasper, Justin C.; Stevens, Michael L. +3 more
We identify and examine the solar wind intervals near the sonic critical point (i.e., M S ∼ 1) observed by the Parker Solar Probe. The near-subsonic wind intervals show similar properties: a low density, an extremely low velocity, a low proton temperature, and essentially no magnetic field deflections compared with the surrounding sol…
Merger-driven Growth of Intermediate-mass Black Holes: Constraints from Hubble Space Telescope Imaging of Hyper-luminous X-Ray Sources
Stern, Daniel; Comerford, Julia M.; Barrows, R. Scott +1 more
Hyper-luminous X-ray sources (HLXs) are extragalactic off-nuclear X-ray sources with luminosities exceeding the theoretical limit for accretion onto stellar-mass compact objects. Many HLXs may represent intermediate-mass black holes (IMBHs) deposited in galaxy halos through mergers, and the properties of the stellar cores surrounding HLXs provide …
Revision of the GeV γ-Ray Emission in the Region of HESS J1813-178 with Fermi-LAT
Xin, Yuliang; Guo, Xiaolei
HESS J1813-178 is one of the brightest and most compact TeV γ-ray sources, and whether its γ-ray emission is associated with supernova remnant (SNR), pulsar wind nebula (PWN), or young stellar cluster (YSC) is still under debate. By analyzing the GeV γ-ray data in the field of HESS J1813-178 using 14 yr of PASS 8 data recorded by the Fermi Large A…
Volatile-rich Sub-Neptunes as Hydrothermal Worlds: The Case of K2-18 b
Fortney, Jonathan J.; Moses, Julianne I.; Zhang, Xi +8 more
Temperate exoplanets between the sizes of Earth and Neptune, known as "sub-Neptunes," have emerged as intriguing targets for astrobiology. It is unknown whether these planets resemble Earth-like terrestrial worlds with a habitable surface, Neptune-like giant planets with deep atmospheres and no habitable surface, or something exotic in between. Re…
Dual-band Observations of the Asymmetric Ring around CIDA 9A: Dead or Alive?
Herczeg, Gregory J.; Johnstone, Doug; Long, Feng +9 more
While the most exciting explanation of the observed dust asymmetries in protoplanetary disks is the presence of protoplanets, other mechanisms can also form the dust features. This paper presents dual-wavelength Atacama Large Millimeter/submillimeter Array observations of a large asymmetric dusty ring around the M-type star CIDA 9A. We detect a du…
Calibrating and Standardizing the Tip of the Red Giant Branch in the Small Magellanic Cloud Using Small-amplitude Red Giants
Anderson, Richard I.; Koblischke, Nolan W.
We investigate the absolute calibration of the tip of the red giant branch (TRGB) in the Small Magellanic Cloud (SMC) using small amplitude red giant stars (SARGs) classified by the Optical Gravitational Lensing Experiment (OGLE). We show that all stars near the SMC's TRGB are SARGs. Distinguishing older and younger RGs near the tip according to t…
Black Hole Scaling Relations in the Dwarf-galaxy Regime with Gaia-Sausage/Enceladus and ωCentauri
Limberg, Guilherme
The discovery of fast moving stars in Milky Way's most massive globular cluster, ωCentauri (ωCen), has provided strong evidence for an intermediate-mass black hole (IMBH). However, ωCen is known to be the stripped nuclear star cluster (NSC) of an ancient, now-destroyed, dwarf galaxy. The best candidate to be the original host progenitor of ωCen is…
Resolved UV and Optical Color Gradients Reveal Environmental Influence on Galaxy Evolution at Redshift z ∼ 1.6
Cooper, M. C.; van Kampen, E.; Demarco, R. +13 more
The changes in colors across a galaxy are intimately connected to the galaxy's formation, growth, quenching history, and dust content. A particularly important epoch in the growth of galaxies is near z ∼ 2, often referred to as "cosmic noon," where galaxies on average reach the peak of their star formation. We study a population of 125 cluster gal…
Determining the Extents, Geometries, and Kinematics of Narrow-line Region Outflows in Nearby Seyfert Galaxies
Rafelski, Marc; Fischer, Travis C.; Crenshaw, D. Michael +5 more
Outflowing gas from supermassive black holes in the centers of active galaxies has been postulated as a major contributor to galactic evolution. To explore the interaction between narrow-line region (NLR) outflows and their host galaxies, we use Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) spectra and Wide Field Camera …
Birds of a Feather: Resolving Stellar Mass Assembly with JWST/NIRCam in a Pair of Kindred z ∼ 2 Dusty Star-forming Galaxies Lensed by the PLCK G165.7+67.0 Cluster
Grogin, Norman A.; Holwerda, Benne W.; Koekemoer, Anton M. +38 more
We present a new parametric lens model for the G165.7+67.0 galaxy cluster, which was discovered with Planck through its bright submillimeter flux, originating from a pair of extraordinary dusty star-forming galaxies (DSFGs) at z ≈ 2.2. Using JWST and interferometric mm/radio observations, we characterize the intrinsic physical properties of the DS…