Search Publications
A Short-term ESPERTA-based Forecast Tool for Moderate-to-extreme Solar Proton Events
Laurenza, M.; Cliver, E. W.; Alberti, T.
The ESPERTA (Empirical model for Solar Proton Event Real Time Alert) forecast tool has a Probability of Detection (POD) of 63% for all >10 MeV events with proton peak intensity ≥10 pfu (i.e., ≥S1 events, S1 referring to minor storms on the NOAA Solar Radiation Storms scale), from 1995 to 2014 with a false alarm rate (FAR) of 38% and a median (m…
Discovery of a z = 7.452 High Equivalent Width Lyα Emitter from the Hubble Space Telescope Faint Infrared Grism Survey
Finkelstein, Steven L.; Koekemoer, Anton M.; Larson, Rebecca L. +19 more
We present the results of an unbiased search for Lyα emission from continuum-selected 5.6 < z < 8.7 galaxies. Our data set consists of 160 orbits of G102 slitless grism spectroscopy obtained with the Hubble Space Telescope(HST)/WFC3 as part of the Faint Infrared Grism Survey (FIGS; PI: Malhotra), which obtains deep slitless spectra of all so…
The Carnegie-Chicago Hubble Program. V. The Distances to NGC 1448 and NGC 1316 via the Tip of the Red Giant Branch
Madore, Barry F.; Freedman, Wendy L.; Beaton, Rachael L. +8 more
The Carnegie-Chicago Hubble Program (CCHP) is recalibrating the extragalactic SN Ia distance scale using exclusively Population II stars. This effort focuses on the Tip of the Red Giant Branch (TRGB) method, whose systematics are entirely independent of the Population I Cepheid-based determinations that have long served as calibrators for the SN I…
Chromospheric Heating due to Cancellation of Quiet Sun Internetwork Fields
Gošić, M.; De Pontieu, B.; Bellot Rubio, L. R. +5 more
The heating of the solar chromosphere remains one of the most important questions in solar physics. Our current understanding is that small-scale internetwork (IN) magnetic fields play an important role as a heating agent. Indeed, cancellations of IN magnetic elements in the photosphere can produce transient brightenings in the chromosphere and tr…
Formation of an Active Region Filament Driven By a Series of Jets
Cao, Wenda; Yan, Xiaoli; Wang, Jincheng +5 more
We present a formation process of a filament in active region NOAA 12574 during the period from 2016 August 11 to 12. Combining the observations of the Global Oscillation Network Group Hα, the Hida spectrum, and the Solar Dynamics Observatory/AIA 304 Å, the formation process of the filament is studied. It is found that cool material (T ∼ 104<…
Magnetic Nulls in the Reconnection Driven by Turbulence
Dunlop, M. W.; Wang, Z.; Fu, H. S. +5 more
For the first time, we use spacecraft measurements to investigate the magnetic nulls in a reconnection event driven by turbulence in the magnetosheath. We particularly focus on the relation between magnetic-null topologies and currents, which can be decomposed into a component perpendicular to spine ({J}\perp ) and a component parallel …
Evidence for a Neutral Iron Line Generated by MeV Protons from Supernova Remnants Interacting with Molecular Clouds
Koyama, Katsuji; Uchida, Hiroyuki; Nobukawa, Masayoshi +6 more
Supernova remnants (SNRs) have been prime candidates for Galactic cosmic-ray accelerators. When low-energy cosmic-ray protons (LECRp) collide with interstellar gas, they ionize neutral iron atoms and emit the neutral iron line (Fe I Kα) at 6.40 keV. We search for the iron K-shell line in seven SNRs from the Suzaku archive data of the Galactic plan…
Ultra-red Galaxies Signpost Candidate Protoclusters at High Redshift
Ivison, R. J.; Omont, A.; Clements, D. L. +20 more
We present images obtained with LABOCA of a sample of 22 galaxies selected via their red Herschel SPIRE colors. We aim to see if these luminous, rare, and distant galaxies are signposting dense regions in the early universe. Our 870 µm survey covers an area of ≈1 deg2 down to an average rms of 3.9 {mJy} {beam}}-1, with …
High-resolution Observations of Flares in an Arch Filament System
Cao, Wenda; Liu, Rui; Ahn, Kwangsu +3 more
We study five sequential solar flares (SOL2015-08-07) occurring in Active Region 12396 observed with the Goode Solar Telescope (GST) at the Big Bear Solar Observatory, complemented by Interface Region Imaging Spectrograph and SDO observations. The main flaring region is an arch filament system (AFS) consisting of multiple bundles of dark filament …
Signatures of Solar Cycle 25 in Subsurface Zonal Flows
Thompson, M. J.; Howe, R.; Komm, R. +5 more
The pattern of migrating zonal flow bands associated with the solar cycle, known as the torsional oscillation, has been monitored with continuous global helioseismic observations by the Global Oscillations Network Group (GONG), together with those made by the Michelson Doppler Imager (MDI) on board the Solar and Heliospheric Observatory (SOHO) and…