Search Publications
Analysis of the Sensitivity of Solar Rotation to Helioseismic Data from GONG, GOLF, and MDI Observations
Eff-Darwich, A.; Korzennik, S. G.; Jiménez-Reyes, S. J. +1 more
Accurate determination of the rotation rate in the radiative zone of the Sun from helioseismic observations requires rotational frequency splittings of exceptional quality as well as reliable inversion techniques. Here we present inferences based on mode parameters calculated from 2088 day MDI, GONG, and GOLF time series that were fitted to estima…
Coronal Hard X-Ray Emission Associated with Radio Type III Bursts
Krucker, Säm; Bale, S. D.; Lin, R. P. +4 more
We report on a purely coronal hard X-ray source detected in a partially disk-occulted solar flare by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) that is associated with radio type III bursts and a suprathermal electron event detected near 1 AU by the WIND 3-D Plasma and Energetic Particle (3DP) instrument. Several observation…
New Young Brown Dwarfs in the Orion Molecular Cloud 2/3 Region
Luhman, K. L.; Smith, J. D.; Megeath, S. T. +7 more
Forty new low-mass members with spectral types ranging from M4 to M9 have been confirmed in the Orion Molecular Cloud (OMC) 2/3 region. Through deep, I-, z'-, J-, H-, and K-band photometry of a 20' × 20' field in OMC 2/3, we selected brown dwarf candidates for follow-up spectroscopy. Low-resolution far-red and near-infrared spectra were obtained f…
The Globular Cluster System of M60 (NGC 4649). I. Canada-France-Hawaii Telescope MOS Spectroscopy and Database
Rey, Soo-Chang; Lee, Myung Gyoon; Hwang, Ho Seong +7 more
We present radial velocity measurements for globular clusters in M60, a giant elliptical galaxy in the Virgo Cluster. Target globular cluster candidates were selected using Washington photometry based on deep 16' × 16' images taken at the KPNO 4 m telescope and using VI photometry derived from Hubble Space Telescope WFPC2 arc…
X-Ray Tail in NGC 7619
Trinchieri, Ginevra; Fabbiano, Giuseppina; Kim, Dong-Woo +1 more
We present new observational results of NGC 7619, an elliptical galaxy with a prominent X-ray tail and a dominant member of the Pegasus group. With Chandra and XMM-Newton observations, we confirm the presence of a long X-ray tail in the southwest direction; moreover, we identify for the first time a sharp discontinuity of the X-ray surface brightn…
Are There Field-Free Gaps near τ = 1 in Sunspot Penumbrae?
Solanki, S. K.; Borrero, J. M.
The vertical stratification of the magnetic field strength in sunspot penumbrae is investigated by means of spectropolarimetric observations at high spatial resolution from the Hinode spacecraft. Assuming that the magnetic field changes linearly with optical depth we find that, in those regions where the magnetic field is more inclined and the Eve…
Broadband X-Ray Spectroscopy of A0535+262 with Suzaku
Mihara, T.; Takahashi, H.; Enoto, T. +9 more
The transient X-ray binary pulsar A0535+262 was observed with Suzaku on 2005 September 14 when the source was in the declining phase of the August-September minor outburst. The ~103 s X-ray pulse profile was strongly energy dependent, with a double-peaked profile in the soft X-ray energy band (<3 keV) and a single-peaked smooth profile in hard …
Optical Surface Brightness Fluctuations of Shell Galaxies toward 100 Mpc
Cantiello, M.; Brocato, E.; Raimondo, G. +1 more
We measure F814W surface brightness fluctuations (SBFs) for a sample of distant shell galaxies with radial velocities ranging from 4000 to 8000 km s-1. The distance at galaxies is then evaluated by using the SBF method. For this purpose, theoretical SBF magnitudes for the HST ACS filters are computed for single-burst stellar populations…
Latitudinal Gradients of Galactic Cosmic Rays during the 2007 Solar Minimum
Mewaldt, R. A.; Gómez-Herrero, R.; Ferreira, S. E. S. +6 more
Ulysses, launched in 1990 October in the maximum phase of solar cycle 22, completed its third out-of-ecliptic orbit in 2008 February. This provides a unique opportunity to study the propagation of cosmic rays over a wide range of heliographic latitudes during different levels of solar activity and different polarities in the inner heliosphere. Com…
Solar Observations of High-Temperature Emission with the Extreme-Ultraviolet Imaging Spectrometer on Hinode
Warren, Harry P.; Brown, Charles M.; Feldman, Uri
We present an analysis of solar coronal emission lines formed above 2.5 MK observed with the Extreme-Ultraviolet Imaging Spectrometer on Hinode during a small flare. Our main purpose is to evaluate the internal consistency of the atomic data available for the observed emission. We find that the observed emission from high-temperature Ca lines (Ca …