Search Publications
The global modulation of Galactic and Jovian electrons in the heliosphere
Potgieter, Marius S.; Nndanganeni, Rendani R.
A full three-dimensional, numerical model is used to study the modulation of Jovian and Galactic electrons from 1 MeV to 50 GeV, and from the Earth into the heliosheath. For this purpose the very local interstellar spectrum and the Jovian electron source spectrum are revisited. It is possible to compute the former with confidence at kinetic energi…
Regional stratigraphy of the south polar layered deposits (Promethei Lingula, Mars): "Discontinuity-bounded" units in images and radargrams
Thomas, Nicolas; Forget, François; Rossi, Angelo Pio +5 more
The Mars South Polar Layered Deposits (SPLD) are the result of depositional and erosional events, which are marked by different stratigraphic sequences and erosional surfaces. To unambiguously define the stratigraphic units at regional scale, we mapped the SPLD on the basis of observed discontinuities (i.e., unconformities, correlative discontinui…
The Evolution of Protoplanetary Disks: Probing the Inner Disk of Very Low Accretors
Reiter, Megan; Calvet, Nuria; Briceño, César +7 more
We report FUV, optical, and NIR observations of three T Tauri stars in the Orion OB1b subassociation with Hα equivalent widths consistent with low or absent accretion and various degrees of excess flux in the mid-infrared. We aim to search for evidence of gas in the inner disk in HST Advanced Camera for Surveys/Solar Blind Channel spectra, and to …
Exospheric escape: A parametrical study
Killen, Rosemary M.; Burger, Matthew H.; Farrell, William M.
The study of exospheres can help us understand the long-term loss of volatiles from planetary bodies due to interactions of planets, satellites, and small bodies with the interplanetary medium, solar radiation, and internal forces including diffusion and outgassing. Recent evidence for water and OH on the Moon has spurred interest in processes inv…
Automated cross-identifying radio to infrared surveys using the LRPY algorithm: a case study
Vaccari, M.; Seymour, N.; Norris, R. P. +5 more
Cross-identifying complex radio sources with optical or infra red (IR) counterparts in surveys such as the Australia Telescope Large Area Survey (ATLAS) has traditionally been performed manually. However, with new surveys from the Australian Square Kilometre Array Pathfinder detecting many tens of millions of radio sources, such an approach is no …
Herschel Observations of Protoplanetary Disks in Lynds 1641
Kim, Kyoung Hee; Fischer, William J.; Calvet, Nuria +7 more
We analyze Herschel Space Observatory observations of 104 young stellar objects with protoplanetary disks in the ∼1.5 Myr star-forming region Lynds 1641 (L1641) within the Orion A Molecular Cloud. We present spectral energy distributions from the optical to the far-infrared including new photometry from the Herschel Photodetector Array Camera and …
Constraining the presence of giant planets in two-belt debris disc systems with VLT/SPHERE direct imaging and dynamical arguments
Hinkley, Sasha; Matthews, Elisabeth; Stapelfeldt, Karl +10 more
Giant, wide-separation planets often lie in the gap between multiple, distinct rings of circumstellar debris: this is the case for the HR 8799 and HD 95086 systems, and even the Solar system where the Asteroid and Kuiper belts enclose the four gas and ice giants. In the case that a debris disc, inferred from an infrared excess in the SED, is best …
Red Supergiants in the JWST Era. I. Near-IR Photometric Diagnostics
Levesque, Emily M.
The Near Infrared Camera (NIRCam) on the James Webb Space Telescope (JWST) will be an incredibly powerful instrument for studying red supergiants (RSGs). The high luminosities and red peak wavelengths of these stars make them ideal targets for JWST/NIRCam. With effective photometric diagnostics in place, imaging RSG populations in multiple filters…
GalMod: A Galactic Synthesis Population Model
Grebel, Eva K.; Zeidler, Peter; Crnojević, Denija +7 more
We present a new Galaxy population synthesis Model, GalMod. GalMod is a star-count model featuring an asymmetric bar/bulge as well as spiral arms and related extinction. The model, initially introduced in Pasetto et al., has been here completed with a central bar, a new bulge description, new disk vertical profiles, and several new bolometric corr…
Calibration sources and filters of the soft x-ray spectrometer instrument on the Hitomi spacecraft
Tsujimoto, Masahiro; Eckart, Megan E.; Leutenegger, Maurice A. +17 more
The soft x-ray spectrometer was designed to operate onboard the Japanese Hitomi (ASTRO-H) satellite. In the beam of this instrument, there was a filter wheel containing x-ray filters and active calibration sources. This paper describes this filter wheel. We show the purpose of the filters and the preflight calibrations performed. In addition, we p…