Search Publications
Evidence of Very Low Metallicity and High Ionization State in a Strongly Lensed, Star-forming Dwarf Galaxy at z= 3.417
Castellano, M.; Pentericci, L.; Merlin, E. +6 more
We investigate the gas-phase metallicity and Lyman continuum (LyC) escape fraction of a strongly gravitationally lensed, extreme emission-line galaxy at z = 3.417, J1000+0221S, recently discovered by the CANDELS team. We derive ionization- and metallicity-sensitive emission-line ratios from H+K band Large Binocular Telescope (LBT)/LUCI medium reso…
Comparison of Extreme Ultraviolet Imaging Spectrometer Observations of Solar Coronal Loops with Alfvén Wave Turbulence Models
van Ballegooijen, A. A.; Imada, S.; Asgari-Targhi, M.
The observed non-thermal widths of coronal emission lines could be due to Alfvén wave turbulence. To test this idea, we examine and analyze the dynamics of an active region observed on 2012 September 7. We use spectral line profiles of Fe XII, Fe XIII, Fe XV, and Fe XVI obtained by the Extreme-ultraviolet Imaging Spectrometer on the it Hinode spac…
The Properties of Lyα Nebulae: Gas Kinematics from Nonresonant Lines
Davé, Romeel; Yang, Yujin; Zabludoff, Ann +1 more
With the Very Large Telescope/X-shooter, we obtain optical and near-infrared spectra of six Lyα blobs at z ~ 2.3. For a total sample of eight Lyα blobs (including two that we have previously studied), the majority (6/8) have broadened Lyα profiles with shapes ranging from a single peak to symmetric or asymmetric double-peaked. The remaining two sy…
Spectral and Timing Nature of the Symbiotic X-Ray Binary 4U 1954+319: The Slowest Rotating Neutron Star in an X-Ray Binary System
Enoto, Teruaki; Makishima, Kazuo; Pottschmidt, Katja +7 more
The symbiotic X-ray binary (SyXB) 4U 1954+319 is a rare system hosting a peculiar neutron star (NS) and an M-type optical companion. Its ~5.4 hr NS spin period is the longest among all known accretion-powered pulsars and exhibited large (~7%) fluctuations over 8 yr. A spin trend transition was detected with Swift/BAT around an X-ray brightening in…
Star Formation Quenching in High-redshift Large-scale Structure: Post-starburst Galaxies in the Cl 1604 Supercluster at z ~ 0.9
Kocevski, Dale D.; Wu, Po-Feng; Lubin, Lori M. +4 more
The Cl 1604 supercluster at z ~ 0.9 is one of the most extensively studied high-redshift large-scale structures, with more than 500 spectroscopically confirmed members. It consists of eight clusters and groups, with members numbering from a dozen to nearly a hundred, providing a broad range of environments for investigating the large-scale environ…
Synchrotron Self-inverse Compton Radiation from Reverse Shock on GRB 120326A
Yamaoka, Kazutaka; Urata, Yuji; Im, Myungshin +6 more
We present multi-wavelength observations of a typical long duration GRB 120326A at z = 1.798, including rapid observations using a Submillimeter Array (SMA) and a comprehensive monitoring in the X-ray and optical. The SMA observation provided the fastest detection to date among seven submillimeter afterglows at 230 GHz. The prompt spectral analysi…
A Prominence Eruption Driven by Flux Feeding from Chromospheric Fibrils
Wang, Yuming; Shen, Chenglong; Wang, S. +4 more
We present multi-wavelength observations of a prominence eruption originating from a quadrupolar field configuration, in which the prominence was embedded in a side arcade. Within the two-day period prior to its eruption on 2012 October 22, the prominence was perturbed three times by chromospheric fibrils underneath, which rose upward, became brig…
Mapping Compound Cosmic Telescopes Containing Multiple Projected Cluster-scale Halos
Zabludoff, Ann I.; Keeton, Charles R.; Wong, Kenneth C. +1 more
Lines of sight with multiple projected cluster-scale gravitational lenses have high total masses and complex lens plane interactions that can boost the area of magnification, or étendue, making detection of faint background sources more likely than elsewhere. To identify these new "compound" cosmic telescopes, we have found directions in the sky w…
Cluster Candidates around Low-power Radio Galaxies at z ~ 1-2 in COSMOS
Castignani, G.; De Zotti, G.; Chiaberge, M. +2 more
We search for high-redshift (z ~1-2) galaxy clusters using low power radio galaxies (FR I) as beacons and our newly developed Poisson probability method based on photometric redshift information and galaxy number counts. We use a sample of 32 FR Is within the Cosmic Evolution Survey (COSMOS) field from the Chiaberge et al. catalog. We derive a rel…
CHARA/MIRC Observations of Two M Supergiants in Perseus OB1: Temperature, Bayesian Modeling, and Compressed Sensing Imaging
Kiss, L. L.; Baron, F.; McAlister, H. A. +12 more
Two red supergiants (RSGs) of the Per OB1 association, RS Per and T Per, have been observed in the H band using the Michigan Infra-Red Combiner (MIRC) instrument at the CHARA array. The data show clear evidence of a departure from circular symmetry. We present here new techniques specially developed to analyze such cases, based on state-of-the-art…