Search Publications
Probing the Puzzle of Behind-the-limb γ-Ray Flares: Data-driven Simulations of Magnetic Connectivity and CME-driven Shock Evolution
Liu, Wei; Li, Gang; Jin, Meng +8 more
Recent detections of high-energy γ-rays from behind-the-limb (BTL) solar flares by the Fermi Gamma-ray Space Telescope pose a puzzle and challenge on the particle acceleration and transport mechanisms. In such events, the γ-ray emission region is located away from the BTL flare site by up to tens of degrees in heliographic longitude. It is thus hy…
First Observation of the Submillimeter Polarization Spectrum in a Translucent Molecular Cloud
Ward-Thompson, Derek; Fissel, Laura M.; Nakamura, Fumitaka +27 more
Polarized emission from aligned dust is a crucial tool for studies of magnetism in the ISM, but a troublesome contaminant for studies of cosmic microwave background polarization. In each case, an understanding of the significance of the polarization signal requires well-calibrated physical models of dust grains. Despite decades of progress in theo…
Interpretation of the Phase Functions Measured by the OSIRIS Instrument for Comet 67P/Churyumov-Gerasimenko
Muinonen, Karri; Agarwal, Jessica; Penttilä, Antti +2 more
We show that the scattering phase functions of the coma and the nucleus of the comet 67P/Churyumov-Gerasimenko measured by the Rosetta/Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) instrument can be reproduced by a particle model involving clustered, densely packed submicrometer-sized grains composed of organic material and l…
Dependence of Coronal Mass Ejection Properties on Their Solar Source Active Region Characteristics and Associated Flare Reconnection Flux
Gopalswamy, Nat; Nandy, Dibyendu; Srivastava, Nandita +2 more
The near-Sun kinematics of coronal mass ejections (CMEs) determine the severity and arrival time of associated geomagnetic storms. We investigate the relationship between the deprojected speed and kinetic energy of CMEs and magnetic measures of their solar sources, reconnection flux of associated eruptive events, and intrinsic flux-rope characteri…
The Morphological Evolution, AGN Fractions, Dust Content, Environments, and Downsizing of Massive Green Valley Galaxies at 0.5 < z < 2.5 in 3D-HST/CANDELS
Fang, Guanwen; Gu, Yizhou; Yuan, Qirong +2 more
To explore the evolutionary connection among red, green, and blue galaxy populations, based on a sample of massive ({M}* > {10}10 {M}⊙ ) galaxies at 0.5 < z < 2.5 in five 3D-HST/CANDELS fields, we investigate the dust content, morphologies, structures, active galactic nucleus (AGN) fractions, and environme…
The Variable Fast Soft X-Ray Wind in PG 1211+143
Reeves, J. N.; Pounds, K. A.; Lobban, A.
The analysis of a series of seven observations of the nearby (z = 0.0809) QSO PG 1211+143, taken with the Reflection Grating Spectrometer (RGS) onboard XMM-Newton in 2014, are presented. The high-resolution soft X-ray spectrum, with a total exposure exceeding 600 ks, shows a series of blueshifted absorption lines from the He and H-like transitions…
An Alternate Approach to Measure Specific Star Formation Rates at 2\lt z\lt 7
Ilbert, Olivier; Davidzon, Iary; Faisst, Andreas L. +2 more
We trace the specific star formation rate (sSFR) of massive star-forming galaxies (≳ {10}10 {{ M }}⊙ ) from z∼ 2 to 7. Our method is substantially different from previous analyses, as it does not rely on direct estimates of star formation rate, but on the differential evolution of the galaxy stellar mass function (SMF). We sh…
The Effect of Magnetic Variability on Stellar Angular Momentum Loss. I. The Solar Wind Torque during Sunspot Cycles 23 and 24
Finley, Adam J.; See, Victor; Matt, Sean P.
The rotational evolution of cool stars is governed by magnetized stellar winds that slow the stellar rotation during their main sequence lifetimes. Magnetic variability is commonly observed in Sun-like stars, and the changing strength and topology of the global field is expected to affect the torque exerted by the stellar wind. We present three di…
ALMA Detections of CO Emission in the Most Luminous, Heavily Dust-obscured Quasars at z > 3
Knudsen, Kirsten K.; Drouart, Guillaume; Fan, Lulu +1 more
We report the results of a pilot study of CO(4 - 3) emission line of three Wide-field Infrared Survey Explorer (WISE)-selected hyper-luminous, dust-obscured quasars (QSOs) with sensitive ALMA Band 3 observations. These obscured QSOs with L bol > 1014 L ⊙ are among the most luminous objects in the universe. All t…
Effective Induction Heating around Strongly Magnetized Stars
Lammer, H.; Fossati, L.; Lüftinger, T. +4 more
Planets that are embedded in the changing magnetic fields of their host stars can experience significant induction heating in their interiors caused by the planet’s orbital motion. For induction heating to be substantial, the planetary orbit has to be inclined with respect to the stellar rotation and dipole axes. Using WX UMa, for which the rotati…