Search Publications
TESS-Keck Survey. V. Twin Sub-Neptunes Transiting the Nearby G Star HD 63935
Batalha, Natalie M.; Latham, David W.; Mayo, Andrew W. +55 more
We present the discovery of two nearly identically sized sub-Neptune transiting planets orbiting HD 63935, a bright (V = 8.6 mag), Sun-like (Teff = 5560 K) star at 49 pc. TESS identified the first planet, HD 63935 b (TOI-509.01), in Sectors 7 and 34. We identified the second signal (HD 63935 c) in Keck High Resolution Echelle Spectromet…
The central region of the enigmatic Malin 1
Saha, Kanak; Barway, Sudhanshu; Dhiwar, Suraj +2 more
Malin 1, being a class of giant low surface galaxies, continues to surprise us even today. The HST/F814W observation has shown that the central region of Malin 1 is more like a normal SB0/a galaxy, while the rest of the disk has the characteristic of a low surface brightness system. The AstroSat/UVIT observations suggest scattered recent star form…
S5: The Destruction of a Bright Dwarf Galaxy as Revealed by the Chemistry of the Indus Stellar Stream
Lewis, Geraint F.; Casey, Andrew R.; Erkal, Denis +14 more
The recently discovered Indus stellar stream exhibits a diverse chemical signature compared to what is found for most other streams due to the abundances of two outlier stars, Indus_0 and Indus_13. Indus_13 exhibits an extreme enhancement in rapid neutron-capture (r-)process elements with [Eu/Fe] = + 1.81. It thus provides direct evidence of the a…
On the mechanism of polarized metre-wave stellar emission
Vedantham, H. K.
Two coherent radio emission mechanisms operate in stellar coronae: plasma emission and cyclotron emission. They directly probe the electron density and magnetic field strength respectively. Most stellar radio detections have been made at cm-wavelengths where it is often not possible to uniquely identify the emission mechanism, hindering the utilit…
The first coronal mass ejection observed in both visible-light and UV H I Ly-α channels of the Metis coronagraph on board Solar Orbiter
Heinzel, P.; Vial, J. -C.; Woch, J. +68 more
Context. The Metis coronagraph on board Solar Orbiter offers a new view of coronal mass ejections (CMEs), observing them for the first time with simultaneous images acquired with a broad-band filter in the visible-light interval and with a narrow-band filter around the H I Ly-α line at 121.567 nm, the so-called Metis UV channel.
Aims: We show…
Probing Jets from Young Embedded Sources: Clues from HST Near-IR [Fe II] Images
Hartigan, Patrick; Giannini, Teresa; Nisini, Brunella +6 more
We present near-infrared [Fe II] images of four Class 0/I jets (HH 1/2, HH 34, HH 111, HH 46/47) observed with the Hubble Space Telescope (HST) Wide Field Camera 3. The unprecedented angular resolution allows us to measure proper motions, jet widths and trajectories, and extinction along the jets. In all cases, we detect the counterjet, which was …
Dynamical modelling of the twisted galaxy PGC 046832
Brinchmann, Jarle; Krajnović, Davor; Emsellem, Eric +2 more
We analyse VLT/MUSE observations of PGC 046832, the brightest cluster galaxy of Abell 3556. The velocity structure of this galaxy is startling and shows two reversals in sign along the minor axis, and one along the major axis. We use triaxial Schwarzschild models to infer the intrinsic shape, central black hole mass, and orbit distribution of this…
Simulating the Solar Minimum Corona in UV Wavelengths with Forward Modeling II. Doppler Dimming and Microscopic Anisotropy Effect
Susino, Roberto; Fineschi, Silvano; Cranmer, Steven R. +5 more
In ultraviolet (UV) spectropolarimetric observations of the solar corona, the existence of a magnetic field, solar wind velocity, and temperature anisotropies modify the linear polarization associated with resonant scattering. Unlike previous empirical models or global models, which present blended results of the above physical effects, in this wo…
Active Region Contributions to the Solar Wind over Multiple Solar Cycles
van Driel-Gesztelyi, Lidia; Green, Lucie M.; Horbury, Timothy S. +1 more
Both coronal holes and active regions are source regions of the solar wind. The distribution of these coronal structures across both space and time is well known, but it is unclear how much each source contributes to the solar wind. In this study we use photospheric magnetic field maps observed over the past four solar cycles to estimate what frac…
Relationship between three-dimensional velocity of filament eruptions and CME association
Ichimoto, Kiyoshi; Ishii, Takako T.; Asai, Ayumi +2 more
It is widely recognised that filament disappearances or eruptions are frequently associated with Coronal Mass Ejections (CMEs). Since CMEs are a major source of disturbances of the space environment surrounding the Earth, it is important to investigate these associations in detail for the better prediction of CME occurrence. However, the proportio…