Search Publications
Evidence of Magnetic Nulls in the Reconnection at Bow Shock
Wang, Z.; Xu, Y.; Fu, H. S. +2 more
Magnetic nulls are believed to play important roles in the energy dissipation during reconnection. Such nulls have been observed in reconnection at the magnetopause, magnetosheath, and magnetotail but have never been observed in reconnection at the bow shock. Recently, four reconnection events were reported at the terrestrial bow shock, by utilizi…
Cloud Atlas: Rotational Spectral Modulations and Potential Sulfide Clouds in the Planetary-mass, Late T-type Companion Ross 458C
Schneider, Glenn; Apai, Dániel; Burgasser, Adam J. +11 more
Measurements of photometric variability at different wavelengths provide insights into the vertical cloud structure of brown dwarfs and planetary-mass objects. In seven Hubble Space Telescope consecutive orbits, spanning ∼10 hr of observing time, we obtained time-resolved spectroscopy of the planetary-mass T8 dwarf Ross 458 C using the near-infrar…
The relationship between dust and [C I] at z = 1 and beyond
Dunlop, J. S.; Simpson, J. M.; McLeod, D. J. +3 more
Measuring molecular gas mass is vital for understanding the evolution of galaxies at high redshifts (z ≳ 1). Most measurements rely on CO as a tracer, but dependencies on metallicity, dynamics, and surface density lead to systematic uncertainties in high-z galaxies, where these physical properties are difficult to observe, and where the physical e…
The VLT-FLAMES Tarantula Survey. XXXI. Radial velocities and multiplicity constraints of red supergiant stars in 30 Doradus
van Loon, J. Th.; Lennon, D. J.; Herrero, A. +10 more
Aims: The incidence of multiplicity in cool, luminous massive stars is relatively unknown compared to their hotter counterparts. In this work we present radial velocity (RV) measurements and investigate the multiplicity properties of red supergiants (RSGs) in the 30 Doradus region of the Large Magellanic Cloud using multi-epoch visible spectr…
Oxygen isotopic ratios in Martian water vapour observed by ACS MIR on board the ExoMars Trace Gas Orbiter
Grigoriev, A.; Montmessin, F.; Korablev, O. +10 more
Oxygen isotope ratios provide important constraints on the history of the Martian volatile system, revealing the impact of several processes that might fractionate them, such as atmospheric loss into space or interaction with the surface. We report infrared measurements of the Martian atmosphere obtained with the mid-infrared channel (MIR) of the …
Chemical abundances and radial velocities in the extremely metal-poor galaxy DDO 68
Tosi, M.; Bellazzini, M.; Cusano, F. +9 more
We present chemical abundances and radial velocities of six H II regions in the extremely metal-poor star-forming dwarf galaxy DDO 68. They are derived from deep spectra in the wavelength range 3500-10 000 Å, acquired with the Multi-Object Double Spectrograph at the Large Binocular Telescope (LBT). In the three regions where the [O III] λ4363 Å li…
Multi-component Decomposition of Astronomical Spectra by Compressed Sensing
Winebarger, Amy R.; Antolin, Patrick; Testa, Paola +9 more
The signal measured by an astronomical spectrometer may be due to radiation from a multi-component mixture of plasmas with a range of physical properties (e.g., temperature, Doppler velocity). Confusion between multiple components may be exacerbated if the spectrometer sensor is illuminated by overlapping spectra dispersed from different slits, wi…
Not So Heavy Metals: Black Hole Feedback Enriches the Circumgalactic Medium
Werk, Jessica K.; Pontzen, Andrew; Christensen, Charlotte +4 more
We examine the effects of supermassive black hole (SMBH) feedback on the circumgalactic medium (CGM) using a cosmological hydrodynamic simulation (ROMULUS25) and a set of four zoom-in “genetically modified” Milky-Way-mass galaxies sampling different evolutionary paths. By tracing the distribution of metals in the CGM, we show that O VI is a sensit…
Hubble Space Telescope Flux Calibration. I. STIS and CALSPEC
Bohlin, Ralph C.; Deustua, Susana E.; de Rosa, Gisella
The precision of absolute flux measurements is quantified for the Space Telescope Imaging Spectrograph (STIS), which is the most important contributor to the CALSPEC standards. With our goal of 1% absolute accuracy, the documentation of the Hubble Space Telescope/CALSPEC flux scale and its subpercent repeatability are of prime importance. While th…
A resonant pair of warm giant planets revealed by TESS
Torres, Guillermo; Nesvorný, David; Kipping, David +4 more
We present the discovery of a pair of transiting giant planets using four sectors of TESS photometry. TOI-216 is a 0.87 M⊙ dwarf orbited by two transiters with radii of 8.2 and 11.3 R⊕, and periods of 17.01 and 34.57 d, respectively. Anticorrelated TTVs are clearly evident indicating that the transiters orbit the same star an…