Search Publications
Ultra-narrow Negative Flare Front Observed in Helium-10830 Å Using the 1.6 m New Solar Telescope
Xu, Yan; Cao, Wenda; Liu, Chang +10 more
Solar flares are sudden flashes of brightness on the Sun and are often associated with coronal mass ejections and solar energetic particles that have adverse effects on the near-Earth environment. By definition, flares are usually referred to as bright features resulting from excess emission. Using the newly commissioned 1.6 m New Solar Telescope …
Detection of Lyman-alpha Emission from a Triply Imaged z = 6.85 Galaxy behind MACS J2129.4-0741
Fontana, Adriano; Pentericci, Laura; Schmidt, Kasper B. +13 more
We report the detection of Lyα emission at ∼9538 Å in the Keck/DEIMOS and Hubble Space Telescope WFC3 G102 grism data from a triply imaged galaxy at z=6.846+/- 0.001 behind galaxy cluster MACS J2129.4-0741. Combining the emission line wavelength with broadband photometry, line ratio upper limits, and lens modeling, we rule out the scenario that th…
The Impact of Accurate Extinction Measurements for X-Ray Spectral Models
Smith, Randall K.; Valencic, Lynne A.; Corrales, Lia
Interstellar extinction includes both absorption and scattering of photons from interstellar gas and dust grains, and it has the effect of altering a source's spectrum and its total observed intensity. However, while multiple absorption models exist, there are no useful scattering models in standard X-ray spectrum fitting tools, such as XSPEC. Non…
Magnetically Dominated Parallel Interstellar Filaments in the Infrared Dark Cloud G14.225-0.506
Zhang, Qizhou; Girart, Josep Miquel; Busquet, Gemma +2 more
The infrared dark cloud G14.225-0.506 (IRDC G14.2) displays a remarkable complex of parallel dense molecular filaments projected on the plane of the sky. Previous studies of dust emission and molecular lines have speculated whether magnetic fields could have played an important role in the formation of such elongated structures, which are hosts to…
The Red Sequence at Birth in the Galaxy Cluster Cl J1449+0856 at z = 2
Finoguenov, A.; Cimatti, A.; Daddi, E. +10 more
We use Hubble Space Telescope/WFC3 imaging to study the red population in the IR-selected, X-ray detected, low-mass cluster Cl J1449+0856 at z = 2, one of the few bona fide established clusters discovered at this redshift, and likely a typical progenitor of an average massive cluster today. This study explores the presence and significance of an e…
TeV Gamma-Ray Observations of the Galactic Center Ridge by VERITAS
Pelassa, V.; Archer, A.; Benbow, W. +73 more
The Galactic Center ridge has been observed extensively in the past by both GeV and TeV gamma-ray instruments revealing a wealth of structure, including a diffuse component and the point sources G0.9+0.1 (a composite supernova remnant) and Sgr A* (believed to be associated with the supermassive black hole located at the center of our Galaxy). Prev…
The Grism Lens-Amplified Survey from Space (GLASS). VII. The Diversity of the Distribution of Star Formation in Cluster and Field Galaxies at 0.3 less than or equal to z less than or equal to 0.7
Pentericci, Laura; Schmidt, Kasper B.; Treu, Tommaso +10 more
Exploiting the slitless spectroscopy taken as part of the Grism Lens-Amplified Survey from Space (GLASS), we present an extended analysis of the spatial distribution of star formation in 76 galaxies in 10 clusters at 0.3\lt z\lt 0.7. We use 85 foreground and background galaxies in the same redshift range as a field sample. The samples are well mat…
A Microfilament-eruption Mechanism for Solar Spicules
Moore, Ronald L.; Sterling, Alphonse C.
Recent investigations indicate that solar coronal jets result from eruptions of small-scale chromospheric filaments, called minifilaments; that is, the jets are produced by scaled-down versions of typical-sized filament eruptions. We consider whether solar spicules might in turn be scaled-down versions of coronal jets, being driven by eruptions of…
Enhanced Star Formation of Less Massive Galaxies in a Protocluster at z = 2.5
Suzuki, Tomoko L.; Koyama, Yusei; Kodama, Tadayuki +5 more
We investigate a correlation between star formation rate (SFR) and stellar mass for Hα emission-line galaxies (HAEs) in one of the richest protoclusters ever known at z ∼ 2.5, the USS 1558-003 protocluster. This study is based on a 9.7 hr narrowband imaging data with MOIRCS on the Subaru telescope. We are able to construct a sample in combination …
The ISLANDS Project. I. Andromeda XVI, An Extremely Low Mass Galaxy Not Quenched by Reionization
McQuinn, Kristen B. W.; Dolphin, Andrew E.; Skillman, Evan D. +14 more
Based on data aquired in 13 orbits of Hubble Space Telescope time, we present a detailed evolutionary history of the M31 dSph satellite Andromeda XVI, including its lifetime star formation history (SFH), the spatial distribution of its stellar populations, and the properties of its variable stars. And XVI is characterized by prolonged star formati…