Search Publications
No hydrogen exosphere detected around the super-Earth HD 97658 b
Ehrenreich, D.; Lecavelier des Etangs, A.; Udry, S. +5 more
The exoplanet HD 97658 b provides a rare opportunity to probe the atmospheric composition and evolution of moderately irradiated super-Earths. It transits a bright K star at a moderate orbital distance of 0.08 au. Its low density is compatible with a massive steam envelope that could photodissociate at high altitudes and become observable as escap…
Super-Eddington QSO RX J0439.6-5311 - I. Origin of the soft X-ray excess and structure of the inner accretion flow
Done, Chris; Ward, Martin; Jin, Chichuan
We report the results from a recent 133 ks XMM-Newton observation of a highly super-Eddington narrow-line Type-1 quasi-stellar object RX J0439.6-5311. This source has one of the steepest active galactic nuclei hard X-ray slopes, in addition to a prominent and smooth soft X-ray excess. Strong variations are found throughout the 0.3-10 keV energy ra…
Challenging Some Contemporary Views of Coronal Mass Ejections. II. The Case for Absent Filaments
DeForest, C. E.; Howard, T. A.; Schneck, U. G. +1 more
When a coronal mass ejection (CME) appears in a coronagraph it often exhibits three parts. This “classic” three-part configuration consists of a bright leading edge, a dark circular- or teardrop-shaped cavity, and a bright core within the cavity. It is generally accepted that these are manifestations of coronal plasma pileup, the driving magnetic …
Calibrating the Planck cluster mass scale with CLASH
Bartlett, J. G.; Evrard, A. E.; Rykoff, E. +5 more
We determine the mass scale of Planck galaxy clusters using gravitational lensing mass measurements from the Cluster Lensing And Supernova survey with Hubble (CLASH). We have compared the lensing masses to the Planck Sunyaev-Zeldovich (SZ) mass proxy for 21 clusters in common, employing a Bayesian analysis to simultaneously fit an idealized CLASH …
The Grism Lens-amplified Survey from Space (Glass). IX. The Dual Origin of Low-mass Cluster Galaxies as Revealed by New Structural Analyses
Schmidt, Kasper B.; Treu, Tommaso; Bradač, Maruša +10 more
Using deep Hubble Frontier Fields imaging and slitless spectroscopy from the Grism Survey from Space, we study 2200 cluster and 1748 field galaxies at 0.2≤slant z≤slant 0.7 to determine the impact of environment on galaxy size and structure at stellar masses {log}{M}* /{M}⊙ > 7.8, an unprecedented limit at these redshifts.…
Instrumental response model and detrending for the Dark Energy Camera
Abbott, T. M. C.; Desai, S.; Gruen, D. +12 more
We describe the model for mapping from sky brightness to the digital output of the Dark Energy Camera (DECam) and the algorithms adopted by the Dark Energy Survey (DES) for inverting this model to obtain photometric measures of celestial objects from the raw camera output. This calibration aims for fluxes that are uniform across the camera field o…
Synchrotron Intensity Gradients as Tracers of Interstellar Magnetic Fields
Lee, Hyeseung; Yuen, Ka Ho; Cho, J. +1 more
On the basis of the modern understanding of MHD turbulence, we propose a new way of using synchrotron radiation: using synchrotron intensity gradients (SIGs) for tracing astrophysical magnetic fields. We successfully test the new technique using synthetic data obtained with 3D MHD simulations and provide the demonstration of the practical utility …
Near-Earth Magnetic Field Effects of Large-Scale Magnetospheric Currents
Le, Guan; Lühr, Hermann; Xiong, Chao +1 more
Magnetospheric currents play an important role in the electrodynamics of near-Earth space. This has been the topic of many space science studies. Here we focus on the magnetic fields they cause close to Earth. Their contribution to the geomagnetic field is the second largest after the core field. Significant progress in interpreting the magnetic f…
CLASH: accurate photometric redshifts with 14 HST bands in massive galaxy cluster cores
Infante, L.; Zheng, W.; Molino, A. +41 more
We present accurate photometric redshifts for galaxies observed by the Cluster Lensing And Supernova survey with Hubble (CLASH). CLASH observed 25 massive galaxy cluster cores with the Hubble Space Telescope in 16 filters spanning 0.2-1.7 µm. Photometry in such crowded fields is challenging. Compared to our previously released catalogues, we…
Critical Height of the Torus Instability in Two-ribbon Solar Flares
Wang, Yuming; Liu, Rui; Liu, Jiajia +5 more
We studied the background field for 60 two-ribbon flares of M-and-above classes during 2011-2015. These flares are categorized into two groups, I.e., eruptive and confined flares, based on whether a flare is associated with a coronal mass ejection or not. The background field of source active regions is approximated by a potential field extrapolat…