Search Publications
The Relation Between EIT Waves and Coronal Mass Ejections
Chen, P. F.
More and more evidence indicates that "EIT waves" are strongly related to coronal mass ejections (CMEs). However, it is still not clear how the two phenomena are related to each other. We investigate a CME event on 1997 September 9, which was well observed by both the EUV Imaging Telescope (EIT) and the high-cadence Mark-III K-Coronameter at Mauna…
Quiet Sun mini-coronal mass ejections activated by supergranular flows
Innes, D. E.; Potts, H. E.; Attie, R. +1 more
Context: The atmosphere of the quiet Sun is controlled by photospheric flows sweeping up concentrations of mixed polarity magnetic field. Along supergranule boundaries and junctions, there is a strong correlation between magnetic flux and bright chromospheric and transition region emission.
Aims: The aim is to investigate the relationship betw…
The Io UV footprint: Location, inter-spot distances and tail vertical extent
Delamere, P. A.; Bonfond, B.; Clarke, J. T. +4 more
The Io footprint (IFP) consists of one or several spots observed in both jovian hemispheres and is related to the electromagnetic interaction between Io and the magnetosphere. These spots are followed by an auroral curtain, called the tail, extending more than 90° longitude in the direction of planetary rotation. We use recent Hubble Space Telesco…
A joint spectro-imaging analysis of the XMM-Newton and HESS observations of the supernova remnant RX J1713.7-3946
Ballet, J.; Lemoine-Goumard, M.; Decourchelle, A. +5 more
Context: The supernova remnant (SNR) RX J1713.7-3946 (also known as G347.3-0.5) is part of the class of remnants dominated by synchrotron emission in X-rays. It is also one of the few shell-type SNRs observed at TeV energies allowing us to investigate particle acceleration at SNRs shock.
Aims: Our goal is to compare spatial and spectral proper…
The Rotating Sunspot in AR 10930
Chae, Jongchul; Min, Soonyoung
We study the pattern and behavior of a rotating sunspot in Active Region 10930. The rotational angular speed has been extracted from the apparent motions of the sunspot determined by applying a new optical technique - called non-linear affine velocity estimator (NAVE) - to high-resolution G-band images taken by the Solar Optical Telescope (SOT) on…
Testing Fundamental Physics with Distant Star Clusters: Analysis of Observational Data on Palomar 14
Djorgovski, S. G.; Côté, P.; Grebel, E. K. +6 more
We use the distant outer halo globular cluster Palomar 14 as a test case for classical versus modified Newtonian dynamics (MOND). Previous theoretical calculations have shown that the line-of-sight velocity dispersion predicted by these theories can differ by up to a factor of 3 for such sparse, remote clusters like Pal 14. We determine the line-o…
Spectral Observations of the Enceladus Plume with Cassini-Vims
Brown, R. H.; Buratti, B. J.; Clark, R. N. +3 more
On 2005 November 27 (day 331), the Visual and Infrared Mapping Spectrometer instrument onboard the Cassini spacecraft obtained high signal-to-noise, spatially resolved measurements of Enceladus' particle plume. These data are processed to obtain spectra of the plume at a range of altitudes between 50 and 300 km from the surface. These spectra show…
The Case of AB Aurigae's Disk in Polarized Light: Is there Truly a Gap?
Schneider, Glenn; Hines, Dean C.; Perrin, Marshall D. +4 more
Using the Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) coronagraph, we have obtained high-contrast 2.0 µm imaging polarimetry and 1.1 µm imaging of the circumstellar disk around AB Aurigae on angular scales of 0.3-3'' (40-550 AU). Unlike previous observations, these data resolve the disk in both total and polarized inten…
Biases and Uncertainties in Physical Parameter Estimates of Lyman Break Galaxies from Broadband Photometry
Ferguson, Henry C.; Giavalisco, Mauro; Somerville, Rachel S. +3 more
We investigate the biases and uncertainties in estimates of physical parameters of high-redshift Lyman break galaxies (LBGs), such as stellar mass, mean stellar population age, and star formation rate (SFR), obtained from broadband photometry. These biases arise from the simplifying assumptions often used in fitting the spectral energy distributio…
Sharpening the Tip of the Red Giant Branch
Madore, Barry F.; Freedman, Wendy L.; Mager, Violet
We introduce a modified detection method for measuring the luminosity of the tip of the red giant branch (TRGB) by introducing the composite magnitude T ≡ I - β[(V - I)xcirc - 1.50], where β is the slope of the tip magnitude as a function of color (or metallicity). The method is specifically designed to account for known systematics due…