Search Publications
The ubiquity and dual nature of ultra-compact dwarfs
Kannappan, Sheila J.; Norris, Mark A.
We present the discovery of several ultra-compact dwarfs (UCDs) located in field/group environments. Examination of these objects, plus literature UCDs, confirms the existence of two distinct formation channels for these compact stellar systems. We find that the UCDs we have discovered around the group elliptical NGC 3923 (and most UCDs in general…
Color and Stellar Population Gradients in Passively Evolving Galaxies at z ~ 2 from HST/WFC3 Deep Imaging in the Hubble Ultra Deep Field
Papovich, Casey; Dickinson, Mark; Ferguson, Henry C. +10 more
We report the detection of color gradients in six massive (stellar mass (M star) > 1010 M ⊙) and passively evolving (specific star formation rate <10-11 yr-1) galaxies at redshift 1.3 < z < 2.5 identified in the Hubble Ultra Deep Field using ultra-deep Hubble Space Telescope (HST) …
The First Observations of Low-redshift Damped Lyα Systems with the Cosmic Origins Spectrograph
Sembach, K. R.; Jenkins, E. B.; Prochaska, J. X. +6 more
We report on the first Cosmic Origins Spectrograph observations of damped Lyα systems (DLAs) and sub-damped Lyα systems (sub-DLAs) discovered in a new survey of the gaseous halos of low-redshift galaxies. From observations of 37 sightlines, we have discovered three DLAs and four sub-DLAs. We measure the neutral gas density ΩH I , and re…
An asteroseismic study of the O9V star HD 46202 from CoRoT space-based photometry
Auvergne, M.; Baudin, F.; Michel, E. +13 more
The O9V star HD 46202, which is a member of the young open cluster NGC 2244, was observed by the CoRoT satellite in October/November 2008 during a short run of 34 days. From the very high-precision light curve, we clearly detect β Cep-like pulsation frequencies with amplitudes of ~0.1 mmag and below. A comparison with stellar models was performed …
The deep XMM-Newton Survey of M 31
Stiele, H.; Pietsch, W.; Haberl, F. +5 more
Aims: The largest Local Group spiral galaxy,
The XMM Cluster Survey: X-ray analysis methodology
Hilton, Matt; Stanford, S. A.; Stott, John P. +20 more
The XMM Cluster Survey (XCS) is a serendipitous search for galaxy clusters using all publicly available data in the XMM-Newton Science Archive. Its main aims are to measure cosmological parameters and trace the evolution of X-ray scaling relations. In this paper we describe the data processing methodology applied to the 5776 XMM observations used …
The x-ray luminous galaxy cluster population at 0.9 < z ≲ 1.6 as revealed by the XMM-Newton Distant Cluster Project
Böhringer, H.; Pratt, G. W.; Rosati, P. +12 more
We present the largest sample to date of spectroscopically confirmed x-ray luminous high-redshift galaxy clusters comprising 22 systems in the range 0.9 as part of the XMM-Newton Distant Cluster Project (XDCP). All systems were initially selected as extended x-ray sources over 76.1 deg2 of non-contiguous deep archival XMM-Newton coverag…
The distribution of solar wind speeds during solar minimum: Calibration for numerical solar wind modeling constraints on the source of the slow solar wind
Arge, C. N.; Odstrcil, D.; Owens, M. J. +2 more
It took the solar polar passage of Ulysses in the early 1990s to establish the global structure of the solar wind speed during solar minimum. However, it remains unclear if the solar wind is composed of two distinct populations of solar wind from different sources (e.g., closed loops which open up to produce the slow solar wind) or if the fast and…
The 1.10- and 1.18-µm nightside windows of Venus observed by SPICAV-IR aboard Venus Express
Bertaux, Jean-Loup; Korablev, Oleg; Bézard, Bruno +2 more
Observations of the 1.10- and 1.18-µm nightside windows by the SPICAV-IR instrument aboard Venus Express were analyzed to characterize the various sources of gaseous opacity and determine the H 2O mole fraction in the lower atmosphere of Venus. We showed that the line profile model of Afanasenko and Rodin (Afanasenko, T.S., Rodin,…
Possible Charge-exchange X-ray Emission in the Cygnus Loop Detected with Suzaku
Katsuda, Satoru; Petre, Robert; Yamaguchi, Hiroya +8 more
X-ray spectroscopic measurements of the Cygnus Loop supernova remnant indicate that metal abundances throughout most of the remnant's rim are depleted to ~0.2 times the solar value. However, recent X-ray studies have revealed in some narrow regions along the outermost rim anomalously "enhanced" abundances (up to ~1 solar). The reason for these ano…