Search Publications
The Nature of Active Galactic Nuclei with Velocity Offset Emission Lines
Harrison, F. A.; Stern, D.; Müller-Sánchez, F. +1 more
We obtained Keck/OSIRIS near-IR adaptive optics-assisted integral-field spectroscopy to probe the morphology and kinematics of the ionized gas in four velocity-offset active galactic nuclei (AGNs) from the Sloan Digital Sky Survey. These objects possess optical emission lines that are offset in velocity from systemic as measured from stellar absor…
ALMA observations of the Th 28 protostellar disk. A new example of counter-rotation between disk and optical jet
Pinte, C.; Ménard, F.; Hales, A. +8 more
Aims: Recently, differences in Doppler shifts across the base of four close classical T Tauri star jets have been detected with the HST in optical and near-ultraviolet (NUV) emission lines, and these Doppler shifts were interpreted as rotation signatures under the assumption of steady state flow. To support this interpretation, it is necessar…
Light walls around sunspots observed by the Interface Region Imaging Spectrograph
Zhang, J.; Hou, Y. J.; Li, T. +1 more
Context. The Interface Region Imaging Spectrograph (IRIS) mission provides high-resolution observations of the chromosphere and transition region. Using these data, some authors have reported the new finding of light walls above sunspot light bridges.
Aims: We try to determine whether the light walls exist somewhere else in active regions in …
A Comprehensive Dust Model Applied to the Resolved Beta Pictoris Debris Disk from Optical to Radio Wavelengths
Rieke, George H.; Gáspár, András; Su, Kate Y. L. +1 more
We investigate whether varying the dust composition (described by the optical constants) can solve a persistent problem in debris disk modeling—the inability to fit the thermal emission without overpredicting the scattered light. We model five images of the β Pictoris disk: two in scattered light from the Hubble Space Telescope (HST)/Space Telesco…
Comparison of absolute gain photometric calibration between Planck/HFI and Herschel/SPIRE at 545 and 857 GHz
Abergel, A.; Bernard, J. -P.; Crill, B. P. +14 more
We compare the absolute gain photometric calibration of the Planck/HFI and Herschel/SPIRE instruments on diffuse emission. The absolute calibration of HFI and SPIRE each relies on planet flux measurements and comparison with theoretical far-infrared emission models of planetary atmospheres. We measure the photometric cross calibration between the …
Earth's magnetosphere and outer radiation belt under sub-Alfvénic solar wind
Lugaz, Noé; Farrugia, Charles J.; Schwadron, Nathan A. +3 more
The interaction between Earth's magnetic field and the solar wind results in the formation of a collisionless bow shock 60,000-100,000 km upstream of our planet, as long as the solar wind fast magnetosonic Mach (hereafter Mach) number exceeds unity. Here, we present one of those extremely rare instances, when the solar wind Mach number reached ste…
Hubble Tarantula Treasury Project V. The Star Cluster Hodge 301: The Old Face of 30 Doradus
Panagia, N.; Larsen, S.; Lennon, D. J. +10 more
Based on color-magnitude diagrams (CMDs) from the Hubble Space Telescope Hubble Tarantula Treasury Project (HTTP) survey, we present the star formation history of Hodge 301, the oldest star cluster in the Tarantula Nebula. The HTTP photometry extends faint enough to reach, for the first time, the cluster pre-main sequence (PMS) turn-on, where the …
On the Progenitors of Local Group Novae. II. The Red Giant Nova Rate of M31
Shafter, A. W.; Bode, M. F.; Darnley, M. J. +1 more
In our preceding paper, Liverpool Telescope data of M31 novae in eruption were used to facilitate a search for their progenitor systems within archival Hubble Space Telescope data, with the aim of detecting systems with red giant secondaries (RG-novae) or luminous accretion disks. From an input catalog of 38 spectroscopically confirmed novae with …
Changing physical conditions in star-forming galaxies between redshifts 0 < z < 4: [O III]/H β evolution
Bowler, R. A. A.; Cullen, F.; McLure, R. J. +3 more
We investigate the redshift evolution of the [O III]/H β nebular emission line ratio for a sample of galaxies spanning the redshift range 0 < z < 4. We compare the observed evolution to a set of theoretical models which account for the independent evolution of chemical abundance, ionization parameter and interstellar medium (ISM) pressure in…
Evidence for large-scale subsurface convection in the Sun
Woodard, M. F.
A helioseismic statistical waveform analysis of subsurface flow was performed on two 720-day time series of SOHO/Michelson Doppler Imager medium-l spherical-harmonic coefficients. The time series coincide with epochs of high and low solar activity. Time-dependent coupling-strength coefficients b^t_s(n,l) of modes of the same radial order n and deg…