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Chandra and Spitzer observations of CDFS X-ray obscured QSOs
Georgakakis, A.; Georgantopoulos, I.; Akylas, A.
We present Chandra and Spitzer data for the 186, extragalactic, hard 2-10 keV X-ray selected sources, which lie in the central part of the Chandra Deep Field South (CDFS). For the vast majority of sources (99.5%), there is a spectroscopic or photometric redshift available. We classify 17 sources as X-ray obscured QSOs, strictly according to X-ray …
A Galaxy in Transition: Structure, Globular Clusters, and Distance of the Star-Forming S0 Galaxy NGC 1533 in Dorado
Meurer, Gerhardt R.; Blakeslee, John P.; Putman, Mary E. +1 more
We use two-band imaging data from the Advanced Camera for Surveys onboard the Hubble Space Telescope for a detailed study of NGC 1533, an SB0 galaxy in the Dorado group surrounded by a ring of H I. NGC 1533 appears to be completing a transition from late to early type: it is red, but not quite dead. Faint spiral structure becomes visible following…
The HeII Fowler lines and the OIII and NIII Bowen fluorescence lines in the symbiotic nova RR Telescopii
Danziger, J.; Bonifacio, P.; Selvelli, P.
Aims:A detailed study of the O III and N III Bowen lines in the spectrum of RR Tel.
Methods: Absolute intensities for the He II, O III, and N III emission lines have been obtained from STIS, UVES, FEROS and IUE data, after re-calibration of UVES and FEROS on the STIS scale.
Results: A new measure of reddening (E(B-V) 0.00) has b…
GQ Lup B Visible and Near-Infrared Photometric Analysis
Macintosh, Bruce; Barman, Travis; Marois, Christian
We have reanalyzed archival HST and Subaru data of the recently discovered planetary mass companion (PMC) GQ Lup B. With these we produce the first R- and I-band photometry of the companion and fit a radius and effective temperature using detailed model atmospheres. We find an effective temperature of 2335+/-100 K, a radius of 0.38+/-0.05 Rso…
On the origin of perennial water ice at the south pole of Mars: A precession-controlled mechanism?
Bibring, J. -P.; Langevin, Y.; Clancy, R. T. +3 more
The poles of Mars are known to have recorded recent (<107 years) climatic changes. While the south polar region appears to have preserved its million-year-old environment from major resurfacing events, except for the small portion containing the CO2 residual cap, the discovery of residual water ice units in areas adjacent …
Photospheric magnetic evolution of super active regions
Romano, P.; Zuccarello, F.
Context: Solar flares are one of the most interesting phenomena of solar activity. Although many authors agree that their energy release is related to magnetic reconnection, the phases preceding the magnetic reconnection process are still unclear in several respects.
Aims: We studied the magnetic flux evolution in 26 super active regions obser…
The Merger in Abell 576: A Line-of-Sight Bullet Cluster?
Bregman, Joel N.; Dupke, Renato A.; Mirabal, Nestor +1 more
Using a combination of Chandra and XMM-Newton observations, we confirmed the presence of a significant velocity gradient along the northeast-southwest direction in the intracluster gas of the cluster Abell 576. The results are consistent with a previous ASCA SIS analysis of this cluster. The error-weighted average over the ACIS-S3 and EPIC MOS1 an…
Initial Observations of Sunspot Oscillations Excited by Solar Flare
Kosovichev, A. G.; Sekii, T.
Observations of a large solar flare on 2006 December 13 using Solar Optical Telescope (SOT) on board the Hinode spacecraft revealed high-frequency oscillations excited by the flare in the sunspot chromosphere. These oscillations are observed in the region of strong magnetic field of the sunspot umbra and may provide a new diagnostic tool for probi…
A study of the Sunyaev-Zel'dovich increment using archival SCUBA data
Halpern, Mark; Scott, Douglas; Zemcov, Michael +2 more
In a search for evidence of the short wavelength increment in the Sunyaev-Zel'dovich (SZ) effect, we have analysed archival galaxy cluster data from the Submillimetre Common User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope, resulting in the most complete pointed survey of clusters at 850µm to date. SCUBA's 850-µm passb…
On the distance of PG 1553+11 . A lineless BL Lacertae object active in the TeV band
Falomo, R.; Uslenghi, M.; Treves, A.
Context: The redshift of
Aims: We intend to provide a lower limit for the distance of the object.
Methods: We used a χ2 procedure to constrain…