Search Publications
A Pilot Survey for C III] Emission in the Reionization Era: Gravitationally Lensed z ∼ 7-8 Galaxies in the Frontier Fields Cluster Abell 2744
Stark, Daniel P.; Ellis, Richard S.; Belli, Sirio +1 more
We report results of a search for C iii] λ λ 1907, 1909 Å emission using Keck’s MOSFIRE spectrograph in a sample of 7 {{z}phot}∼ 7-8 candidates (H∼ 27) lensed by the Hubble Frontier Field cluster Abell 2744. Earlier work has suggested the promise of using the C iii] doublet for redshift confirmation of galaxies in the reionization era g…
Extremely Large EUV Late Phase of Solar Flares
Wang, Yuming; Shen, Chenglong; Liu, Rui +3 more
The second peak in the Fe xvi 33.5 nm line irradiance observed during solar flares by the Extreme-Ultraviolet Variability Experiment (EVE) is known as the EUV late phase. Our previous paper in 2013 by Liu et al. found that the main emissions in the late phase are originated from large-scale loop arcades that are closely connected to but different …
Radio Timing and Optical Photometry of the Black Widow System PSR J1953+1846A in the Globular Cluster M71
Dalessandro, E.; Ransom, S. M.; Ferraro, F. R. +6 more
We report on the determination of the astrometric, spin, and orbital parameters for PSR J1953+1846 A, a “black widow” binary millisecond pulsar in the globular cluster M71. By using the accurate position and orbital parameters obtained from radio timing, we identified the optical companion in Advanced Camera for Surveys/Hubble Space Telescope imag…
Observations and Modeling of North-South Asymmetries Using a Flux Transport Dynamo
Tripathi, Durgesh; Shetye, Juie; Dikpati, Mausumi
The peculiar behavior of solar cycle 23 and its prolonged minima has been one of the most studied problems over the past few years. In the present paper, we study the asymmetries in active region magnetic flux in the northern and southern hemispheres during the complete solar cycle 23 and the rising phase of solar cycle 24. During the declining ph…
Co-spatial Long-slit UV/Optical AL Spectra of 10 Galactic Planetary Nebulae with HST/STIS. I. Description of the Observations, Global Emission-line Measurements, and CNO Abundances
Corradi, Romano L. M.; Balick, Bruce; Shaw, Richard A. +3 more
We present observations and initial analysis from a Hubble Space Telescope (HST) Cycle 19 program using STIS to obtain the first co-spatial, UV-optical spectra of 10 Galactic planetary nebulae (PNs). Our primary objective was to measure the critical emission lines of carbon and nitrogen with unprecedented signal-to-noise ratio (S/N) and spatial re…
Revision of Earth-sized Kepler Planet Candidate Properties with High-resolution Imaging by the Hubble Space Telescope
Wright, Jason T.; Ciardi, David R.; Gilliland, Ronald L. +1 more
We present the results of our Hubble Space Telescope program and describe how our analysis methods were used to re-evaluate the habitability of some of the most interesting Kepler planet candidates. Our program observed 22 Kepler Object of Interest (KOI) host stars, several of which were found to be multiple star systems unresolved by Kepler. We u…
The Formation of Iris Diagnostics. VIII. Iris Observations in the C II 133.5 nm Multiplet.
De Pontieu, Bart; Carlsson, Mats; Rathore, Bhavna +1 more
The C ii 133.5 nm multiplet has been observed by NASA’s Interface Region Imaging Spectrograph (IRIS) in unprecedented spatial resolution. The aims of this work are to characterize these new observations of the C ii lines, place them in context with previous work, and to identify any additional value the C ii lines bring when compared with other sp…
A Minor Merger Caught in the Act of Fueling the Active Galactic Nucleus in Mrk 509
Kraemer, S. B.; Crenshaw, D. M.; Storchi-Bergmann, T. +3 more
In recent observations by the Hubble Space Telescope (HST) as part of a campaign to discover locations and kinematics of AGN outflows, we found that Mrk 509 contains a 3'' (~2100 pc) linear filament in its central region. Visible in both optical continuum and [O III] imaging, this feature resembles a "check mark" of several knots of emission that …
The Interstellar Medium and Feedback in the Progenitors of the Compact Passive Galaxies at z ~ 2
Finkelstein, Steven L.; Santini, Paola; Bell, Eric F. +24 more
Quenched galaxies at z > 2 are nearly all very compact relative to z ~ 0, suggesting a physical connection between high stellar density and efficient, rapid cessation of star-formation. We present rest-frame UV spectra of Lyman-break galaxies (LBGs) at z ~ 3 selected to be candidate progenitors of the quenched galaxies at z ~ 2 based on their c…
Nearby Clumpy, Gas Rich, Star-forming Galaxies: Local Analogs of High-redshift Clumpy Galaxies
Guzmán, R.; Garland, C. A.; Pisano, D. J. +3 more
Luminous compact blue galaxies (LCBGs) have enhanced star formation rates (SFRs) and compact morphologies. We combine Sloan Digital Sky Survey data with H i data of 29 LCBGs at redshift z ∼ 0 to understand their nature. We find that local LCBGs have high atomic gas fractions (∼50%) and SFRs per stellar mass consistent with some high-redshift star-…