Search Publications
High-resolution Near-infrared Imaging of Submillimeter Galaxies
Lutz, Dieter; Baker, Andrew J.; Tacconi, Linda J. +2 more
We present F110W (~J) and F160W (~H) observations of 10 submillimeter galaxies (SMGs) obtained with the Hubble Space Telescope's (HST's) NICMOS camera. Our targets have optical redshifts in the range 2.20 <= z <= 2.81 confirmed by millimeter CO or mid-IR spectroscopy, guaranteeing that the two bands sample the rest-frame optical with the Bal…
The Future of the Sun: An Evolved Solar Twin Revealed by CoRoT
Porto de Mello, G. F.; Castro, M.; da Costa, J. S. +3 more
The question of whether the Sun is peculiar within the class of solar-type stars has been the subject of active investigation over the past three decades. Although several solar twins have been found with stellar parameters similar to those of the Sun (albeit in a range of Li abundances and with somewhat different compositions), their rotation per…
HST far-ultraviolet imaging of DG Tauri. Fluorescent molecular hydrogen emission from the wide opening-angle outflow
Schmitt, J. H. M. M.; Güdel, M.; Eislöffel, J. +4 more
One of the most thoroughly studied jets from all young stellar objects is the jet of DG Tau, which we imaged in the far-ultraviolet with the Hubble Space Telescope for the first time. These high spatial resolution images were obtained with long-pass filters and allow us to construct images tracing mainly H2 and C iv emission. We find th…
The Dynamics of the Solar Radiative Zone
Eff-Darwich, A.; Korzennik, S. G.
The dynamics of the solar radiative interior are still poorly constrained by comparison to the convective zone. This disparity is even more marked when we attempt to derive meaningful temporal variations. Many data sets contain a small number of modes that are sensitive to the inner layers of the Sun, but we found that the estimates of their uncer…
X-Ray Absorption of High-redshift Quasars
Behar, Ehud; Eitan, Assaf
The soft X-ray photoelectric absorption of high-z quasars has been known for two decades, but has no unambiguous astrophysical context. We construct the largest sample to date of 58 high-redshift quasars (z > 0.45) selected from the XMM-Newton archive based on a high photon count criterion (>1800). We measure the optical depth τ at 0.5 keV a…
An archive study of 18 old novae. I. The UV spectra
Selvelli, P.; Gilmozzi, R.
Aims: We present an overview of the UV spectral properties of old novae as a class. The data and results of this paper, together with data from the outburst phases, will be utilized in a follow-up study to determine statistical properties and to investigate correlations among the physical parameters of the quiescent and eruptive phases.
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Ultraviolet and visual flux and line variations of one of the least variable Bp stars HD 64740
Skarka, M.; Krtička, J.; Janík, J. +4 more
Context. The light variability of hot magnetic chemically peculiar stars is typically caused by the flux redistribution in spots with peculiar abundance. This raises the question why some stars with surface abundance spots show significant rotational light variability, while others do not.
Aims: We study the Bp star HD 64740 to investigate ho…
The XMM-Newton SSC survey of the Galactic plane
Motch, C.; Pakull, M.; Barcons, X. +17 more
Many different classes of X-ray sources contribute to the Galactic landscape at high energies. Although the nature of the most luminous X-ray emitters is now fairly well understood, the population of low-to-medium X-ray luminosity (LX = 1027-34 erg s-1) sources remains much less studied, our knowledge being mostly …
A New Hα Emission-line Survey in the Orion Nebula Cluster
Pál, A.; Kun, M.; Szegedi-Elek, E. +3 more
We present results from an Hα emission line survey in a 1 deg2 area centered on the Orion Nebula Cluster, obtained with the Wide Field Grism Spectrograph 2 on the 2.2 m telescope of the University of Hawaii. We identified 587 stars with Hα emission, 99 of which, located mainly in the outer regions of the observed area, have not appeared…
Accretion disk wind as explanation for the broad-line region structure in NGC 5548
Kollatschny, W.; Zetzl, M.
Context. Supermassive black holes in the centers of active galactic nuclei (AGN) are surrounded by broad-line regions (BLRs). The broad emission lines seen in the AGN spectra are emitted in this spatially unresolved region.
Aims: We intend to obtain information on the structure and geometry of this BLR based on observed line profiles.
Me…