Search Publications
The Envelope Kinematics and a Possible Disk around the Class 0 Protostar within BHR7
Bourke, Tyler L.; Dunham, Michael M.; Tobin, John J. +2 more
We present a characterization of the protostar embedded within the BHR7 dark cloud, based on both photometric measurements from the near-infrared to millimeter and interferometric continuum and molecular line observations at millimeter wavelengths. We find that this protostar is a Class 0 system, the youngest class of protostars, measuring its bol…
Constraining the parameter space of comet simulation experiments
Hagermann, Axel; Kaufmann, Erika
Our interpretation of the data returned by Rosetta and other cometary missions is based on the predictions of theoretical models and the results of laboratory experiments. For example, Kossacki et al. (2015) showed that 67P's surface hardness reported by Spohn et al. (2015) can be explained by sintering. The present work supports Rosetta's observa…
Bright Network, UVA, and the Physical Modeling of Solar Spectral and Total Irradiance in Recent Solar Cycles
Fontenla, J. M.; Landi, E.
In this paper we study the total solar irradiance (TSI) and the spectral solar irradiance (SSI) by applying the solar disk image decomposition algorithm (SDIDA) and solar irradiance synthesis algorithm (SISA) methods. These methods were applied to space-based observations in previous works, but in this work, they are applied to ground-based observ…
Quantifying Turbulent Dynamics Found within the Plasma Sheets of Multiple Solar Flares
McKenzie, David E.; Freed, Michael S.
It is vital to our understanding of solar flares that we discern how turbulent motion can affect the magnetic reconnection process. The objective of this study is to quantify the velocity and vorticity structures inherent in the observed motions found in a plasma sheet above arcades during a solar flare. The most noticeable features in these plasm…
Reconstruction of asteroid spin states from Gaia DR2 photometry
Hanuš, J.; Ďurech, J.
Context. In addition to stellar data, Gaia Data Release 2 (DR2) also contains accurate astrometry and photometry of about 14 000 asteroids covering 22 months of observations.
Aims: We used Gaia asteroid photometry to reconstruct rotation periods, spin axis directions, and the coarse shapes of a subset of asteroids with enough observations. On…
Accurate radial velocity and metallicity of the Large Magellanic Cloud old globular clusters NGC 1928 and NGC 1939
Cole, A. A.; Hwang, N.; Angelo, M. S. +2 more
We present results obtained from spectroscopic observations of red giants located in the fields of the Large Magellanic Cloud (LMC) globular clusters (GCs) NGC 1928 and NGC 1939. We used the GMOS and AAOmega+2dF spectrographs to obtain spectra centred on the Ca II triplet, from which we derived individual radial velocities (RVs) and metallicities.…
A Seasonally Recurrent Annular Cyclone in Mars Northern Latitudes and Observations of a Companion Vortex
Gondet, B.; Forget, F.; Hueso, R. +12 more
We study a seasonally recurrent cyclone and related cloud phenomena observed on Mars at Ls 120°, latitude 60°N, and longitude 90°W from images obtained with cameras in different spacecraft between 1995 and 2018. A remarkable double cyclone formed in 2012 and we present a detailed study of its dynamics using images from Mars Express and …
The oxygen isotopic composition (18O/16O) in the dust of comet 67P/Churyumov-Gerasimenko measured by COSIMA on-board Rosetta
Hilchenbach, M.; Engrand, C.; Kissel, J. +5 more
The oxygen isotopic ratio 18O/16O has been measured in cometary gas for a wide variety of comets, but the only measurements in cometary dust were performed by the Stardust cometary sample return mission. Most such measurements find a value of the ratio that is consistent with Vienna Standard Mean Ocean Water (VSMOW) within er…
The Advanced Spectral Library (ASTRAL): Reference Spectra for Evolved M Stars
Ayres, Thomas R.; Carpenter, Kenneth G.; Nielsen, Krister E. +3 more
The HST Treasury Program Advanced Spectral Library Project: Cool Stars was designed to collect representative, high-quality UV spectra of eight evolved F-M type cool stars. The Space Telescope Imaging Spectrograph (STIS) echelle spectra of these objects enable investigations of a broad range of topics, including stellar and interstellar astrophysi…
XMM-Newton observations of the Southeastern radio relic in Abell 3667
Vink, Jacco; Akamatsu, Hiroki; Storm, Emma +1 more
Radio relics, elongated, non-thermal, structures located at the edges of galaxy clusters, are the result of synchrotron radiation from cosmic ray electrons accelerated by merger-driven shocks at the cluster outskirts. However, X-ray observations of such shocks in some clusters suggest that they are too weak to efficiently accelerate electrons via …