Search Publications
Testing Lyα Emission-line Reconstruction Routines at Multiple Velocities in One System
Redfield, Seth; Drake, Jeremy J.; France, Kevin +6 more
The 1215.67 Å H I Lyα emission line dominates the ultraviolet flux of low-mass stars, including the majority of known exoplanet hosts. Unfortunately, strong attenuation by the interstellar medium (ISM) obscures the line core in most stars, requiring the intrinsic Lyα flux to be reconstructed based on fits to the line wings. We present a test of th…
Direct Far-infrared Metal Abundances (FIRA). I. M101
Smith, J. D.; Groves, B.; Linden, S. T. +12 more
Accurately determining gas-phase metal abundances within galaxies is critical as metals strongly affect the physics of the interstellar medium. To date, the vast majority of widely used gas-phase abundance indicators rely on emission from bright optical lines, whose emissivities are highly sensitive to the electron temperature. Alternatively, dire…
A Molecular Gas Ring Hidden in the Sombrero Galaxy
Fadda, Dario; Sutter, Jessica
We present Herschel, ALMA, and MUSE observations of the molecular ring of Messier 104, also known as the Sombrero galaxy. These previously unpublished archival data shed new light on the content of the interstellar medium of M104. In particular, molecular hydrogen measured by CO emission and dust measured by far-infrared light are uniformly distri…
Unresolved z 8 Point Sources and Their Impact on the Bright End of the Galaxy Luminosity Function
Stiavelli, Massimo; Treu, Tommaso; Trenti, Michele +7 more
The distribution and properties of the first galaxies and quasars are critical pieces of the puzzle in understanding galaxy evolution and cosmic reionization. Previous studies have often excluded unresolved sources as potential low-redshift interlopers. We combine broadband color and photometric redshift analysis with morphological selections to i…
Yellow Post-asymptotic-giant-branch Stars as Standard Candles. I. Calibration of the Luminosity Function in Galactic Globular Clusters
Bond, Howard E.; Ciardullo, Robin; Siegel, Michael H. +1 more
We use the results of a survey for low-surface-gravity stars in Galactic (and LMC) globular clusters to show that "yellow" post-asymptotic-branch (yPAGB) stars are likely to be excellent extragalactic standard candles, capable of producing distances to early-type galaxies that are accurate to a couple of percent. We show that the mean bolometric m…
A 4 kpc Molecular Gas Lane in Cygnus A
Nyland, Kristina; Decarli, Roberto; Perley, Daniel A. +4 more
We present the discovery of a 4 kpc molecular gas lane in the Cygnus A host galaxy, using Atacama Large Millimeter/submillimeter Array CO 2-1 observations. The gas lane is oriented roughly perpendicular to the projected radio jet axis. The CO emission generally follows the clumpy dust lanes seen in Hubble Space Telescope I-band images. The total m…
Causal Interaction between the Subsurface Rotation Rate Residuals and Radial Magnetic Field in Different Timescales
Howe, Rachel; Inceoglu, Fadil; Loto'aniu, Paul T. M.
We studied the presence and spatiotemporal characteristics and evolution of the variations in the differential rotation rates and radial magnetic fields in the Schwabe and quasi-biennial-oscillation (QBO) timescales. To achieve these objectives, we used rotation rate residuals and radial magnetic field data from the Michelson Doppler Imager on the…
A Multiwavelength Study of the Highly Asymmetrical Debris Disk around HD 111520
Crotts, Katie A.; Matthews, Brenda C.; Duchêne, Gaspard +7 more
We observed the nearly edge-on debris disk system HD 111520 at the HJ and K1 near-infrared (NIR) bands using both the spectral and polarization modes of the Gemini Planet Imager. With these new observations, we have performed an empirical analysis in order to better understand the disk morphology and its highly asymmetrical nature. We find that th…
The Common Envelope Origins of the Fast Jet in the Planetary Nebula M 3-38
Guerrero, M. A.; Toalá, J. A.; Rodríguez-López, C. +3 more
We present the analysis of Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía (MEGARA) high-dispersion integral field spectroscopic observations of the bipolar planetary nebula (PN) M 3-38. These observations unveil the presence of a fast outflow aligned with the symmetry axis of M 3-38 that expands with a velocity of up to ±225 km s
Modeling a Coronal Mass Ejection as a Magnetized Structure with EUHFORIA
Singh, Jagdev; Asvestari, E.; Sindhuja, G. +1 more
We studied an Earth-directed coronal mass ejection (CME) that erupted on 2015 March 15. Our aim was to model the CME flux rope as a magnetized structure using the European Heliospheric Forecasting Information Asset (EUHFORIA). The flux rope from eruption data (FRED) output was applied to the EUHFORIA spheromak CME model. In addition to the geometr…