Search Publications
The Possible z=0.83 Precursors of z=0, M* Early-Type Cluster Galaxies
Kelson, D. D.; Ford, H. C.; Demarco, R. +8 more
We examine the distribution of stellar masses of galaxies in MS 1054.4-0321 and Cl 0152.7-1357, two X-ray-selected clusters of galaxies at z=0.83. Our stellar mass estimates, from spectral energy distribution fitting, reproduce the dynamical masses as measured from velocity dispersions and half-light radii with a scatter of 0.2 dex in the mass for…
The X-Ray Properties of Active Galactic Nuclei with Double-peaked Balmer Lines
Brandt, W. N.; Schneider, Donald P.; Eracleous, Michael +2 more
Double-peaked Balmer line profiles originate in the accretion disks of a few percent of optically selected active galactic nuclei (AGNs). The reasons behind the strong low-ionization line emission from the accretion disks of these objects are still uncertain. In this paper, we characterize the X-ray properties of 39 double-peaked Balmer line AGNs,…
Variations in the D/H Ratio of Extended Sight Lines from Far Ultraviolet Spectroscopic Explorer Observations
Hébrard, Guillaume; Oliveira, Cristina M.
We use new FUSE data to determine the column densities of interstellar D I, N I, O I, Fe II, and H2 along the HD 41161 and HD 53975 sight lines. Together with N(H I) from the literature, we derive D/H, N/H, and O/H ratios. These sight lines have logN(H I)>21.00 and probe gas up to ~1300 pc, allowing us to determine the gas-phase D/H …
The Automatic Predictability of Super Geomagnetic Storms from halo CMEs associated with Large Solar Flares
Yang, Guo; Wang, Haimin; Yurchyshyn, Vasyl +3 more
We investigate the relationship between magnetic structures of coronal mass ejection (CME) source regions and geomagnetic storms, in particular, the super storms when the Dst index decreases below −200 nT. By examining all full halo CMEs that erupted between 1996 and 2004, we selected 73 events associated with M-class and X-class solar …
Multiple Triangulation Analysis: another approach to determine the orientation of magnetic flux ropes
Wei, Y.; Zong, Q. -G.; Dunlop, M. W. +5 more
Another approach (Multiple Triangulation Analysis, MTA) is presented to determine the orientation of magnetic flux rope, based on 4-point measurements. A 2-D flux rope model is used to examine the accuracy of the MTA technique in a theoretical way. It is found that the precision of the estimated orientation is dependent on both the spacecraft sepa…
The Prediction of a Supersoft X-Ray Phase during the 2006 Outburst of RS Ophiuchi
Kato, Mariko; Hachisu, Izumi
RS Ophiuchi is one of the well-observed recurrent novae and also a candidate progenitor of Type Ia supernovae. Its sixth recorded outburst was discovered on 2006 February 12. Detection of a supersoft X-ray phase will provide us with a firm confirmation of hydrogen shell burning on the white dwarf, and its turn-on/turnoff dates strongly constrain t…
Multi-Site Spectrographic and Heliographic Observations of Radio Fine Structure on April 10, 2001
Tan, Chengming; Yan, Yihua; Huang, Guangli +5 more
We present results of the first simultaneous observations of zebra patterns (ZPs) with super-fine spiky structure in the microwave range made at two observatories ∼1000 km apart (Beijing and Nanjing, China). The fine structure was recorded by a spectra polarimeter in the 5.2 - 7.6 and 2.8 - 3.6 GHz ranges at the Huairou station and by the spectrom…
Light dark matter annihilations into two photons
Boehm, C.; Orloff, J.; Salati, P.
We compute the pair annihilation cross section of light (spin-0) dark matter particles into two photons and discuss the detectability of the monochromatic line associated with these annihilations.
Star formation in QSO host galaxies
Lacy, Mark; Stockton, Alan; Canalizo, Gabriela +1 more
Many of the conditions that are necessary for starbursts appear to be important in the triggering of QSOs. However, it is still debatable whether starbursts are ubiquitously present in galaxies harboring QSOs. In this paper we review our current knowledge from observations of the role of starbursts in different types of QSOs. Post-starburst stella…
Sensitivity of solar off-limb line profiles to electron density stratification and the velocity distribution anisotropy
Solanki, S. K.; Raouafi, N. -E.
The effect of the electron density stratification on the intensity profiles of the H I Ly-α line and the O VI and Mg X doublets formed in solar coronal holes is investigated. We employ an analytical 2-D model of the large scale coronal magnetic field that provides a good representation of the corona at the minimum of solar activity. We use the mas…