Search Publications
The effects of atmospheric dust and solar radiation on the dayside ionosphere of Mars derived from 17 years of Mars Express radio science observations
Pätzold, M.; González-Galindo, F.; Witasse, O. +5 more
This work combines 17 years of Mars Express radio science (MaRS) observations with proxies for insolation and local/global atmospheric dust to investigate the combined and individual effects on the dayside ionosphere of Mars from the top down to the ionospheric base.
The increase in insolation from orbital apocenter to pericenter in combinati…A hard look at the X-ray spectral variability of NGC 7582
Nardini, Emanuele; Zoghbi, Abderahmen; Miller, Jon M. +5 more
NGC 7582 (z = 0.005264; D = 22.5 Mpc) is a highly variable, changing-look AGN. In this work, we explore the X-ray properties of this source using XMM-Newton and NuSTAR archival observations in the 3 - 40 keV range, from 2001 to 2016. NGC 7582 exhibits a long-term variability between observations but also a short-term variability in two observation…
Exotica in the globular cluster M4, studied with Chandra, HST, and the VLA
Anderson, Jay; Zhao, Jiaqi; Heinke, Craig O. +3 more
Using the Hubble Ultraviolet Globular Cluster Survey (HUGS) and additional HST archival data, we have carried out a search for optical counterparts to the low-luminosity Chandra X-ray sources in the globular cluster M4 (NGC 6121). We have also searched for optical or X-ray counterparts to radio sources detected by the VLA. We find 24 new confident…
Unexpected energetic particle observations near the Sun by Parker Solar Probe and Solar Orbiter
McComas, D. J.; Rodríguez-Pacheco, J.; Wimmer-Schweingruber, R. F. +6 more
Solar energetic particles (SEPs) from suprathermal (few keV) up to relativistic (∼few GeV) energies are accelerated at the Sun in association with solar flares and coronal mass ejection-driven shock waves. Although our knowledge of the origin, acceleration, and transport of these particles from close to the Sun through the interplanetary medium ha…
Scaling relations of X-ray luminous clusters in the Hyper Suprime-Cam Subaru Strategic Program field
Fukazawa, Yasushi; Okabe, Nobuhiro; Poon, Helen +2 more
We present the XMM-Newton X-ray analysis of 19 X-ray luminous galaxy clusters of low- to mid-redshift (<0.4) selected from the MCXC (Meta-Catalog of X-Ray Detected Clusters of Galaxies) cluster catalogue in the Hyper Suprime-Cam Subaru Strategic Programme field. We derive the hydrostatic equilibrium mass and study scaling relations using (i) th…
Effects of coronal mass ejection orientation on its propagation in the heliosphere
Temmer, M.; Vršnak, B.; Dumbović, M. +3 more
Context. In the scope of space weather forecasting, it is crucial to be able to more reliably predict the arrival time, speed, and magnetic field configuration of coronal mass ejections (CMEs). From the time a CME is launched, the dominant factor influencing all of the above is the interaction of the interplanetary CME (ICME) with the ambient plas…
Material around the Centaur (2060) Chiron from the 2018 November 28 UT Stellar Occultation
Bosh, Amanda S.; Person, Michael J.; Levine, Stephen E. +5 more
A stellar occultation of Gaia DR3 2646598228351156352 by the Centaur (2060) Chiron was observed from the South African Astronomical Observatory on 2018 November 28 UT. Here we present a positive detection of material surrounding Chiron from the 74-inch telescope for this event. Additionally, a global atmosphere is ruled out at the tens of microbar…
The MeerKAT Galaxy Clusters Legacy Survey: star formation in massive clusters at 0.15 < z < 0.35
Knowles, K.; Clarke, T. E.; Hilton, M. +5 more
We investigate dust-unbiased star formation rates (SFRs) as a function of the environment in 20 massive clusters ($M_{200}\gt 4\times 10^{14}\, {\rm M}_{\odot }$) between 0.15 < $z$ < 0.35 using radio luminosities (L1.4GHz) from the recently released MeerKAT Galaxy Cluster Legacy Survey catalogue. We use optical data from the Dark…
N2/CO ratio in comets insensitive to orbital evolution
Mousis, O.; Jehin, E.; Anderson, S. E. +2 more
Comets are seen as depleted in nitrogen compared to the protosolar value, but a small number exhibit significantly higher than typical N2/CO ratios: C/1908 R1 (Morehouse), C/1940 R2 (Cunningham), C/1947 S1 (Bester), C/1956 R1 (Arend-Roland), C/1957 P1 (Mrkos), C/1961 R1 (Humason), C/1969 Y1 (Bennett), C/1973 E1 (Kohoutek), C/1975 V1-A (…
Photometric IGM tomography with Subaru/HSC: the large-scale structure of Ly α emitters and IGM transmission in the COSMOS field at z ∼ 5
Ono, Yoshiaki; Ouchi, Masami; Hennawi, Joseph F. +5 more
We present a novel technique called 'photometric IGM tomography' to map the intergalactic medium (IGM) at z ≃ 4.9 in the COSMOS field. It utilizes deep narrow-band (NB) imaging to photometrically detect faint Ly α forest transmission in background galaxies across the Subaru/Hyper-Suprime Cam (HSC)'s $1.8\rm \, sq.\, deg$ field of view and locate L…