Search Publications
UV Counterpart of an X-Ray Ultrafast Outflow in IRAS 17020+4544
Kriss, Gerard A.; Mehdipour, Missagh; Nicastro, Fabrizio +7 more
We report on the discovery of a UV absorption counterpart of a low-ionization X-ray ultrafast outflow (UFO) in the narrow-line Seyfert 1 galaxy IRAS 17020+4544. This UV signature of the UFO is seen as a narrow and blueshifted Lyα absorption feature in the far-UV spectrum, taken with the Cosmic Origins Spectrograph (COS) on the Hubble Space Telesco…
TIC 114936199: A Quadruple Star System with a 12 Day Outer-orbit Eclipse
Kostov, Veselin B.; Powell, Brian P.; Rappaport, Saul A. +19 more
We report the discovery with TESS of a remarkable quadruple star system with a 2+1+1 configuration. The two unique characteristics of this system are that (i) the inner eclipsing binary (stars Aa and Ab) eclipses the star in the outermost orbit (star C), and (ii) these outer fourth-body eclipses last for ~12 days, the longest of any such system kn…
Measuring the α-abundance of Subsolar-metallicity Stars in the Milky Way's Central Half-parsec: Testing Globular Cluster and Dwarf Galaxy Infall Scenarios
Bentley, Rory O.; Kerzendorf, Wolfgang; Do, Tuan +4 more
While the Milky Way nuclear star cluster (MW NSC) has been studied extensively, how it formed is uncertain. Studies have shown it contains a solar and supersolar metallicity population that may have formed in situ, along with a subsolar-metallicity population that may have formed via mergers of globular clusters and dwarf galaxies. Stellar abundan…
Magnetic Helicity Evolution and Eruptive Activity in NOAA Active Region 11158
Pariat, E.; Green, L. M.; Valori, G. +3 more
Coronal mass ejections are among the Sun's most energetic activity events yet the physical mechanisms that lead to their occurrence are not yet fully understood. They can drive major space weather impacts at Earth, so knowing why and when these ejections will occur is required for accurate space weather forecasts. In this study we use a 4 day time…
Disks and Outflows in the Intermediate-mass Star-forming Region NGC 2071 IR
Li, Zhi-Yun; Sheehan, Patrick D.; Megeath, S. Thomas +13 more
We present Atacama Large Millimeter Array band 6/7 (1.3 mm/0.87 mm) and Very Large Array Ka-band (9 mm) observations toward NGC 2071 IR, an intermediate-mass star-forming region. We characterize the continuum and associated molecular line emission toward the most luminous protostars, i.e., IRS1 and IRS3, on ~100 au (0.″2) scales. IRS1 is partly re…
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…
Revising Properties of Planet-Host Binary Systems. I. Methods and Pilot Study
Kraus, Adam L.; Mann, Andrew W.; Sullivan, Kendall
To fully leverage the statistical strength of the large number of planets found by projects such as the Kepler survey, the properties of planets and their host stars must be measured as accurately as possible. One key population for planet demographic studies is circumstellar planets in close binaries (ρ < 50 au), where the complex dynamical en…