Search Publications
Kinematics of the Local Spiral Structure Revealed by Young Stars in Gaia DR3
Xu, Ye; Liu, Dejian; Hao, Chaojie +4 more
Using young open clusters and O-B2-type stars in Gaia Data Release 3, we investigate the kinematics of the local spiral structure. In general, the young sources in the outer spiral arms may present larger peculiar motions than those in the inner spiral arms. The young open clusters appear to have smaller peculiar motions than the O-B2-type stars, …
The Origin of Extremely Nonradial Solar Wind Outflows
Janardhan, P.; Chakrabarty, D.; Fujiki, K. +2 more
The origin of nonradial solar wind flows and their effect on space weather are poorly understood. Here we present a detailed investigation of 12 nonradial solar wind events during solar cycles 23-24, covering the period 1995-2017. In all these events the azimuthal flow angles of the solar wind exceed 6° as measured at the L1 Lagrangian point of th…
Astrometric Calibration and Performance of the Dark Energy Spectroscopic Instrument Focal Plane
Moustakas, J.; Brooks, D.; Doel, P. +46 more
The Dark Energy Spectroscopic Instrument, consisting of 5020 robotic fiber positioners and associated systems on the Mayall telescope at Kitt Peak, Arizona, is carrying out a survey to measure the spectra of 40 million galaxies and quasars and produce the largest 3D map of the universe to date. The primary science goal is to use baryon acoustic os…
Simultaneous Mesoscale Polar Cusp Field-Aligned Currents Measured on Mid- and Low-Altitude Satellites
Dunlop, M. W.; Dong, X. -C.; Xiao, C. +3 more
Using a conjunction of Cluster in the mid-altitude dayside magnetosphere and Swarm in the low-altitude ionosphere, we show, by employing multi-spacecraft analysis, that matched, strong magnetic perturbations and the corresponding mesoscale field-aligned current (FAC) structures are measured in the high latitude polar cusp region during the 7 Octob…
TOI-908: a planet at the edge of the Neptune desert transiting a G-type star
Latham, David W.; Fernández Fernández, Jorge; Wheatley, Peter J. +41 more
We present the discovery of an exoplanet transiting TOI-908 (TIC-350153977) using data from TESS sectors 1, 12, 13, 27, 28, and 39. TOI-908 is a T = 10.7 mag G-dwarf (Teff = 5626 ± 61 K) solar-like star with a mass of 0.950 ± 0.010 M⊙ and a radius of 1.028 ± 0.030 R⊙. The planet, TOI-908 b, is a 3.18 ± 0.16 R⊕…
Investigating kinematics and dynamics of three open clusters towards Galactic anticentre
Bisht, D.; Rangwal, Geeta; Yadav, R. K. S. +2 more
We present the intracluster kinematics and dynamics of three open clusters: NGC 1193, NGC 2355, and King 12 by incorporating kinematical and photometric data from Gaia DR3, as well as a ground-based telescope. After selecting cluster members based on proper motion data, clusters' fundamental and structural parameters are investigated. We found the…
Oort Constants and Local Stellar Kinematics from GCNS
Qi, Zhaoxiang; Guo, Sufen
Oort constants and local kinematics are vital parameters with which to study the structure and dynamics of the Milky Way. When GCNS was published, it provided a clean sample of stars in the solar vicinity, which gives us an ideal tool with which to determine these parameters. Our aim was to calculate the reliable Oort constants with GCNS. We deter…
Large Photospheric Doppler Shift in Solar Active Region 12673. I. Field-aligned Flows
Sun, Xudong; Welsch, Brian T.; Quintero Noda, C. +3 more
Delta (δ) sunspots sometimes host fast photospheric flows along the central magnetic polarity inversion line (PIL). Here we study the strong Doppler shift signature in the central penumbral light bridge of solar active region NOAA 12673. Observations from the Helioseismic and Magnetic Imager (HMI) indicate highly sheared and strong magnetic fields…
AGN feedback in an infant galaxy cluster: LOFAR-Chandra view of the giant FRII radio galaxy J103025+052430 at z = 1.7
Prandoni, I.; Vignali, C.; Gilli, R. +19 more
In the nearby universe, jets from active galactic nuclei (AGN) are observed to have a dramatic impact on their surrounding extragalactic environment. The effect of jets at high redshift (z > 1.5) is instead much more poorly constrained. However, studying the jet impact at cosmic noon, the epoch in which both star formation and AGN activity peak…
Constraints on the ultrafast outflows in the narrow-line Seyfert 1 galaxy Mrk 1044 from high-resolution time- and flux-resolved spectroscopy
Guainazzi, Matteo; Bianchi, Stefano; Jin, Chichuan +5 more
Ultrafast outflows (UFOs) have been revealed in a large number of active galactic nuclei (AGN) and are regarded as promising candidates for AGN feedback on the host galaxy. The nature and launching mechanism of UFOs are not yet fully understood. Here we perform a time- and flux-resolved X-ray spectroscopy on four XMM-Newton observations of a highl…