Search Publications
Chandra and Magellan/FIRE follow-up observations of PSO167-13: An X-ray weak QSO at z = 6.515
Bauer, F. E.; Brandt, W. N.; Vignali, C. +19 more
Context. The discovery of hundreds of quasi-stellar objects (QSOs) in the first gigayear of the Universe powered by already grown supermassive black holes (SMBHs) challenges our knowledge of SMBH formation. In particular, investigations of z > 6 QSOs that present notable properties can provide unique information on the physics of fast SMBH grow…
CAPOS: The bulge Cluster APOgee Survey. II. The intriguing "Sequoia" globular cluster FSR 1758
Cohen, Roger E.; Beers, Timothy C.; Minniti, Dante +16 more
We present results from a study of 15 red giant members of the intermediate-metallicity globular cluster (GC) FSR 1758 using high-resolution, near-infrared spectra collected with the Apache Point Observatory Galactic Evolution Experiment II survey (APOGEE-2) that were obtained as part of CAPOS (the bulge Cluster APOgee Survey). Since its very rece…
Estimates of the change rate of solar mass and gravitational constant based on the dynamics of the Solar System
Pitjeva, E. V.; Pitjev, N. P.; Pavlov, D. A. +1 more
The estimate of the change rate of the solar gravitational parameter d(GM⊙)∕dt is obtained from processing modern positional observations of planets and spacecraft. Observations were processed and parameters were determined basing on the numerical planetary ephemeris EPM2019. The obtained annual decrease in solar mass M⊙ acco…
Evolution of anisotropic turbulence in the fast and slow solar wind: Theory and Solar Orbiter measurements
Fedorov, A.; Horbury, T. S.; Louarn, P. +8 more
Aims: Solar Orbiter (SolO) was launched on February 9, 2020, allowing us to study the nature of turbulence in the inner heliopshere. We investigate the evolution of anisotropic turbulence in the fast and slow solar wind in the inner heliosphere using the nearly incompressible magnetohydrodynamic (NI MHD) turbulence model and SolO measurements…
Parker Solar Probe observations of He/H abundance variations in SEP events inside 0.5 au
Mitchell, D. G.; McComas, D. J.; Bale, S. D. +24 more
Aims: The Parker Solar Probe (PSP) orbit provides an opportunity to study the inner heliosphere at distances closer to the Sun than previously possible. Due to the solar minimum conditions, the initial orbits of PSP yielded only a few solar energetic particle (SEP) events for study. Recently during the fifth orbit, at distances from 0.45 to 0…
Interactions between large-scale radio structures and gas in a sample of optically selected type 2 quasars
Humphrey, A.; Storchi-Bergmann, T.; Bellocchi, E. +5 more
Context. The role of radio mode feedback in non radio-loud quasars needs to be explored in depth to determine its true importance. Its effects can be identified based on the evidence of interactions between the radio structures and the ambient ionised gas.
Aims: We investigate this interaction in a sample of 13 optically selected type 2 quasa…
Solar wind current sheets and deHoffmann-Teller analysis. First results from Solar Orbiter's DC electric field measurements
André, N.; Fedorov, A.; Lavraud, B. +25 more
Context. Solar Orbiter was launched on 10 February 2020 with the purpose of investigating solar and heliospheric physics using a payload of instruments designed for both remote and in situ studies. Similar to the recently launched Parker Solar Probe, and unlike earlier missions, Solar Orbiter carries instruments designed to measure low-frequency D…
Discovery of O stars in the tidal Magellanic Bridge. Stellar parameters, abundances, and feedback of the nearest metal-poor massive stars and their implication for the Magellanic System ecology
Hamann, W. -R.; Oskinova, L. M.; Ramachandran, V.
The Magellanic Bridge, stretching between the Small and the Large Magellanic Cloud (SMC and LMC), is the nearest tidally stripped intergalactic environment. The Bridge has a significantly low average metallicity of Z ≲ 0.1 Z⊙. Here we report the first discovery of O-type stars in the Magellanic Bridge. Three massive O stars were identif…
Outflows, envelopes, and disks as evolutionary indicators in Lupus young stellar objects
de Gregorio-Monsalvo, I.; Lopez, C.; Fernández-López, M. +4 more
Context. The Lupus star-forming complex includes some of the closest low-mass star-forming regions, and together they house objects that span evolutionary stages from prestellar to premain sequence.
Aims: By studying seven objects in the Lupus clouds from prestellar to protostellar stages, we aim to test if a coherence exists between commonly…
Evidence of the multi-thermal nature of spicular downflows. Impact on solar atmospheric heating
Joshi, Jayant; Martínez-Sykora, Juan; De Pontieu, Bart +4 more
Context. Spectroscopic observations of the emission lines formed in the solar transition region commonly show persistent downflows on the order of 10−15 km s−1. The cause of such downflows, however, is still not fully clear and has remained a matter of debate.
Aims: We aim to understand the cause of such downflows by studying the c…