Search Publications
Faint Fuzzies and the Formation of Lenticular Galaxies
Brodie, Jean; Burkert, Andreas; Larsen, Soeren
We investigate the dynamical state of a new class of extended star clusters known as ``faint fuzzies,'' which were discovered in two nearby S0 galaxies, NGC 1023 and NGC 3384. It is shown that the faint fuzzies of NGC 1023 lie in a fast-rotating ringlike structure within the galactic disk with mean radius of 5 kpc, rotational velocity of 200 km s<…
Spectral energy distribution of the metagalactic ionizing radiation field from QSO absorption spectra
Levshakov, S. A.; Agafonova, I. I.; Centurión, M. +1 more
A computational procedure is presented to estimate the spectral shape of the ionizing background between 1 and 10 Ryd by analyzing optically thin absorption systems in the spectra of high redshift quasars. The procedure is based on the response surface methodology from the theory of experimental design. The shape of the recovered UV background at …
Outburst of the X-ray Transient SAX J1818.6-1703 Detected by the INTEGRAL Observatory in September 2003
Sunyaev, R. A.; Grebenev, S. A.
During the observation of the Galactic-center field by the INTEGRAL observatory on September 9, 2003, the IBIS/ISGRI gamma-ray telescope detected a short (several-hours-long) intense (∼380 mCrab at the peak) outburst of hard radiation from the X-ray transient SAX J1818.6-1703. Previously, this source was observed only once in 1998 during a similar…
Integral Field Spectroscopy of the Central Regions of 3C 120: Evidence of a Past Merging Event
Christensen, L.; García-Lorenzo, B.; Mediavilla, E. +2 more
Optical integral field spectroscopy (IFS), combined with Hubble Space Telescope (HST) WFPC imaging, was used to characterize the central regions of the Seyfert 1 radio galaxy 3C 120. We carried out the analysis of the data, deriving intensity maps of different emission lines and the continua at different wavelengths from the observed spectra. Appl…
A Study of Flare-associated X-Ray Plasma Ejections. I. Association with Coronal Mass Ejections
Cho, K. -S.; Moon, Y. -J.; Park, Y. D. +2 more
We have made a comprehensive statistical study of the relationship between flare-associated X-ray plasma ejections and coronal mass ejections (CMEs). For this we considered all flare-mode data in Yohkoh SXT observations from 1999 April to 2001 March and then selected 279 limb flares seen at longitudes greater than 60°. For these events, we identif…
The enigmatic B[e]-star Henize 2-90: the non-spherical mass loss history from an analysis of forbidden lines
Borges Fernandes, M.; Kraus, M.; Lamers, H. J. G. L. M. +1 more
We study the optical spectrum of the exciting B[e] star
XMM-Newton Observations of Red AGNs
Wilkes, B. J.; Hines, D. C.; Smith, P. S. +5 more
XMM-Newton spectra of five red 2MASS active galactic nuclei (AGNs), selected from a sample observed by Chandra to be relatively X-ray bright and to cover a range of hardness ratios, confirm the presence of substantial absorbing material in three sources with optical classifications ranging from type 1 to type 2. A flat (hard) power-law continuum i…
Shock-cloud interaction in the Vela SNR observed with XMM-Newton
Miceli, M.; Bocchino, F.; Reale, F. +1 more
We analyzed an XMM-Newton EPIC observation of a bright knot, named FilD, in the northern rim of the Vela SNR, where the shock has encountered a cloud. The good combination of sensitivity, spectral, and spatial resolution allowed us to describe the internal structure of the observed ISM clouds and to obtain estimates of their temperature, density, …
From the Sun to the outer heliosphere: Modeling and analyses of the interplanetary propagation of the October/November (Halloween) 2003 solar events
Sun, Wei; Intriligator, Devrie S.; Dryer, Murray +3 more
We use the space weather validated 3-D HAFv2 model to help us study the interplanetary propagation of the October/November 2003 solar eruptions from the Sun to >90 AU and over a wide range of heliolongitudes and heliolatitudes. The HAFv2 model predictions at ACE (1 AU), Ulysses (5.23 AU), Cassini (8.67 AU), Voyager 2 (73 AU), and Voyager 1 (93 …
Maps of Titan's surface from 1 to 2.5 µm
Drossart, Pierre; Coustenis, Athena; Lai, Olivier +4 more
We have acquired resolved images of Titan with the adaptive optics systems PUEO/KIR at the CFHT (Hawaii) and NAOS/CONICA at the VLT (Chile). We report here on images and maps (when data at several orbital phases are available) of Titan's surface from observations taken during the last 4 years (2001-2004) in all the methane windows between 1 and 2.…