Search Publications
Missions
Journals
Publication Years
The lithified aeolian dune field adjacent to the Apollinaris Sulci, Mars: Geological history and paleo-wind record
Chojnacki, Matthew; Edgett, Kenneth S.; Day, Mackenzie +1 more
A lithified aeolian dune field in the Apollinaris Sulci region of Mars presents a unique opportunity to study ancient aeolian processes and paleo-wind conditions during an earlier episode of martian climate history. The ancient dunes occur inside an eroded, partly-filled impact structure. The petrified dune field retains its original geomorphology…
Rotation of hot normal, peculiar and Be stars from space photometry
Balona, L. A.
The periods of 34 376 main-sequence stars hotter than 6000 K are derived from Kepler, K2, and TESS light curves. From the effective temperatures and GAIA DR3 luminosities, the radii, and hence the equatorial rotational velocities, can be estimated. Comparison with the projected rotational velocities shows that the photometric periods are indisting…
Stellar Loci. VI. An Updated Catalog of the Best and Brightest Metal-poor Stars
Huang, Yang; Beers, Timothy C.; Li, Haining +3 more
We employ Gaia, Two Micron All Sky Survey, and ALLWISE photometry, as well as astrometric data from Gaia, to search for relatively bright very metal-poor (VMP; [Fe/H] < -2.0) giant star candidates using three different criteria: (1) the derived Gaia photometric metallicities from Xu et al., (2) the lack of stellar molecular absorption near 4.6 …
The frequency and mass-ratio distribution of binaries in clusters - I. Description of the method and application to M67
Albrow, Michael D.; Ulusele, Isaac H.
We present a new method for probabilistic generative modelling of stellar colour-magnitude diagrams (CMDs) to infer the frequency of binary stars and their mass-ratio distribution. The method invokes a mixture model to account for overlapping populations of single stars, binaries, and outliers in the CMD. We apply the model to Gaia observations of…
Evolution of the critical torus instability height and coronal mass ejection likelihood in solar active regions
O'Kane, Jennifer; James, Alexander W.; Williams, David R.
Aims: Working towards improved space weather predictions, we aim to quantify how the critical height at which the torus instability drives coronal mass ejections (CMEs) varies over time in a sample of solar active regions.
Methods: We model the coronal magnetic fields of 42 active regions and quantify the critical height at their central…
Is the Subsurface Meridional Flow Zero at the Equator?
Komm, R.
We study the subsurface meridional flow and its divergence from the surface to a depth of about 16 Mm at the equator and its variation with the solar cycle derived with ring-diagram analysis applied to Michelson Doppler Imager (MDI) Dynamics Program, Global Oscillation Network Group (GONG), and Helioseismic and Magnetic Imager (HMI) Dopplergrams. …
LoVoCCS. I. Survey Introduction, Data Processing Pipeline, and Early Science Results
Cooper, M. C.; Donahue, Megan; Miyatake, Hironao +19 more
We present the Local Volume Complete Cluster Survey (LoVoCCS; we pronounce it as "low-vox" or "law-vox," with stress on the second syllable), an NSF's National Optical-Infrared Astronomy Research Laboratory survey program that uses the Dark Energy Camera to map the dark matter distribution and galaxy population in 107 nearby (0.03 < z < 0.12…
The Twisted Magnetic Field of the Protobinary L483
Pattle, Kate; Coudé, Simon; Bourke, Tyler L. +16 more
We present H-band (1.65 µm) and SOFIA HAWC+ 154 µm polarization observations of the low-mass core L483. Our H-band observations reveal a magnetic field that is overwhelmingly in the E-W direction, which is approximately parallel to the bipolar outflow that is observed in scattered IR light and in single-dish 12CO observation…
Inconspicuous Solar Polar Coronal X-Ray Jets as the Source of Conspicuous Hinode/EUV Imaging Spectrometer Doppler Outflows
Harra, Louise K.; Panesar, Navdeep K.; Moore, Ronald L. +3 more
We examine in greater detail five events previously identified as being sources of strong transient coronal outflows in a solar polar region in Hinode/Extreme Ultraviolet (EUV) Imaging Spectrometer (EIS) Doppler data. Although relatively compact or faint and inconspicuous in Hinode/X-ray Telescope (XRT) soft-X-ray (SXR) images and in Solar Dynamic…
Exploring the Link between the X-Ray Power Spectra and Energy Spectra of Active Galactic Nuclei
Jin, Chichuan; Yuan, Weimin; Yang, Haonan
Active galactic nuclei (AGN) are generally considered the scaled-up counterparts of X-ray binaries (XRBs). It is known that the power spectral density (PSD) of the X-ray emission of XRBs shows significant evolution with spectral state. It is not clear whether AGN follow a similar evolutionary trend, however, though their X-ray emission and the PSD…