Search Publications
Three-dimensional analyses of an aspherical coronal mass ejection and its driven shock
Feng, Li; Lu, Lei; Gan, Weiqun +4 more
Context. Observations reveal that shocks can be driven by fast coronal mass ejections (CMEs) and play essential roles in particle accelerations. A critical ratio, δ, derived from a shock standoff distance normalized by the radius of curvature (ROC) of a CME, allows us to estimate shock and ambient coronal parameters. However, true ROCs of CMEs are…
Decoding NGC 628 with radiative transfer methods
Popescu, C. C.; Pricopi, D.; Natale, G. +2 more
We present an axi-symmetric model for the ultraviolet (UV)-to-submillimetre (submm) images of the nearly face-on spiral galaxy NGC 628. It was calculated using a radiative transfer (RT) code, accounting for the absorption and re-emission of starlight by dust in the interstellar medium of this galaxy. The code incorporates emission from Polycyclic …
On the Same Wavelength as the Space Telescope Imaging Spectrograph
Ayres, Thomas R.
The Hubble Space Telescope Imaging Spectrograph (STIS) is a powerful tool for high spectral resolution ultraviolet (UV; 1150-3200 Å) studies of bright cosmic sources. However, achieving the superb wavelength precision inherent in its UV echelle channels is hampered by subtle camera distortions that are not fully compensated for by the CALSTIS pipe…
Down but Not Out: Properties of the Molecular Gas in the Stripped Virgo Cluster Early-type Galaxy NGC 4526
Meier, David S.; Davis, Timothy A.; Young, Lisa M. +2 more
We present Atacama Large Millimeter/submillimeter Array data on the 3 mm continuum emission, CO isotopologues (12CO, 13CO, and C18O), and high-density molecular tracers (HCN, HCO+, HNC, HNCO, CS, CN, and CH3OH) in NGC 4526. These data enable a detailed study of the physical properties of the m…
The Substructures in the Anticenter Region of the Milky Way
Zhao, G.; Chen, Y. Q.; Zhang, Z. +3 more
We investigated the observational properties of Triangulum-Andromeda (TriAnd), Monoceros Ring (MRi), and Anti-Center Stream (ACS) in the anticenter region using K giants, M giants, and RGB stars from LAMOST and SDSS survey. The Friends of Friends algorithm was applied to select member stars of these structures. We found a new spur of TriAnd at l ~…
Accretion and Extinction Variations in the Low-mass Pre-main-sequence Binary System WX Cha
Pál, András; Ábrahám, Péter; Kóspál, Ágnes +5 more
Light curves of young star systems show photometric variability due to different kinematic and physical processes. One of the main contributors to the photometric variability is the changing mass accretion rate, which regulates the interplay between the forming young star and the protoplanetary disk. We collected high-resolution spectroscopy in ei…
The rotation of planet-hosting stars
Feldmann, Robert; Helled, Ravit; Sibony, Yves
Understanding the distribution of angular momentum during the formation of planetary systems is a key topic in astrophysics. Data from the Kepler and Gaia missions allow to investigate whether stellar rotation is correlated with the presence of planets around Sun-like stars. Here, we perform a statistical analysis of the rotation period of 493 pla…
Monitoring observations of SMC X-1's excursions (MOOSE)-I. Programme description and initial high state spectral results
Clarkson, William I.; Dage, Kristen C.; Bahramian, Arash +8 more
SMC X-1 has exhibited three superorbital period excursions since the onset of X-ray monitoring beginning with the Rossi X-ray Timing Explorer's launch in 1995. TheNeutron star Interior Composition Explorer has recently probed a fourth observed excursion beginning in 2021 with our programme monitoring observations of SMC X-1's excursions (MOOSE). T…
A Highway for Atmospheric Ion Escape from Earth during the Impact of an Interplanetary Coronal Mass Ejection
Zong, Qiugang; Xie, Lun; Zhang, Hui +9 more
A single satellite hardly measures the overall ion escape rate from a planet. Therefore, the question concerning the long-term atmospheric evolution of whether a planetary magnetic field protects its atmosphere or aggravates atmospheric loss remains unresolved. Here, combined data from multiple platforms including Cluster, DMSP, IMAGE, and Polar s…
A detailed star formation history for the extremely diffuse Andromeda XIX dwarf galaxy
Williams, Benjamin F.; Gilbert, Karoline M.; Dolphin, Andrew +3 more
We present deep imaging of the ultradiffuse Andromeda XIX dwarf galaxy from the Advance Camera for Surveys on the Hubble Space Telescope which resolves its stellar populations to below the oldest main-sequence turn-off. We derive a full star formation history for the galaxy using MATCH, and find no evidence of star formation in the past 8 Gyr. We …