Search Publications
Three Lyα Emitters at z ~ 6: Early GMOS/Gemini Data from the GLARE Project
Bunker, Andrew J.; Glazebrook, Karl; McCarthy, Patrick J. +14 more
We report spectroscopic detection of three z~6 Lyα-emitting galaxies, in the vicinity of the Hubble Ultra Deep Field, from the early data of the Gemini Lyman Alpha at Reionisation Era (GLARE) project. Two objects, GLARE 3001 (z=5.79) and GLARE 3011 (z=5.94), are new detections and are fainter in z' (z'AB=26.37 and …
The Far-Infrared Spectrum of Arp 220
Cernicharo, José; Smith, Howard A.; González-Alfonso, Eduardo +1 more
Infrared Space Observatory Long Wavelength Spectrometer grating observations of the ultraluminous infrared galaxy Arp 220 shows absorption in molecular lines of OH, H2O, CH, NH, and NH3, as well as in the [O I] 63 µm line and emission in the [C II] 158 µm line. We have modeled the continuum and the emission/absorp…
An interplanetary shock traced by planetary auroral storms from the Sun to Saturn
Vourlidas, Angelos; Hansen, Kenneth C.; Prangé, Renée +4 more
A relationship between solar activity and aurorae on Earth was postulated long before space probes directly detected plasma propagating outwards from the Sun. Violent solar eruption events trigger interplanetary shocks that compress Earth's magnetosphere, leading to increased energetic particle precipitation into the ionosphere and subsequent auro…
Chandra and XMM-Newton Observations of the Nucleus of Centaurus A
Hardcastle, M. J.; Worrall, D. M.; Forman, W. R. +4 more
We present X-ray spectra of the nucleus of the nearby radio galaxy Centaurus A from observations with the XMM-Newton EPIC CCD cameras (two exposures separated by 12 months) and the Chandra HETGS. For the first time in an FR I type galaxy, we resolve fluorescent Kα emission from cold, neutral, or near-neutral iron at 6.4 keV, with an rms line width…
The Fundamental Plane of Field Early-Type Galaxies at z = 1
Rix, H. -W.; van der Wel, A.; Franx, M. +1 more
We present deep VLT spectra of early-type galaxies at z~1 in the Chandra Deep Field-South, from which we derive velocity dispersions. Together with structural parameters from Hubble Space Telescope imaging, we can study the fundamental plane for field early-type galaxies at that epoch. We determine accurate mass-to-light ratios (M/L) and colors fo…
Multi-element abundance Doppler imaging of the rapidly oscillating Ap star HR 3831
Piskunov, N.; Kochukhov, O.; Drake, N. A. +1 more
We investigate magnetic field geometry and surface distribution of chemical elements in the rapidly oscillating Ap star HR 3831. Results of the model atmosphere analysis of the spectra of this star are combined with the Hipparcos parallax and evolutionary models to obtain new accurate estimates of the fundamental stellar parameters: Teff
Performance and surface scattering models for the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS)
Gurnett, D. A.; Johnson, W. T. K.; Orosei, R. +10 more
The primary scientific objective of the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS), which will be on board Mars Express mission scheduled for launch in 2003, is to map the distribution and depth of the liquid water/ice interface in the upper kilometres of the crust of Mars. MARSIS will also provide unique information to he…
The Far-Infrared Spectrum of the Sagittarius B2 Region: Extended Molecular Absorption, Photodissociation, and Photoionization
Cernicharo, José; Goicoechea, Javier R.; Rodríguez-Fernández, Nemesio J.
We present large-scale 9'×27' (~25pc×70pc) far-IR observations around Sgr B2 using the Long-Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). The spectra are dominated by the strong continuum emission of dust, the widespread molecular absorption of light hydrides (OH, CH, and H2O), and th…
The Stellar Populations of Low-Luminosity Active Galactic Nuclei. I. Ground-based Observations
Heckman, Timothy; Schaerer, Daniel; Leitherer, Claus +6 more
We present a spectroscopic study of the stellar populations of low-luminosity active galactic nuclei (LLAGNs). Our main goal is to determine whether the stars that live in the innermost (100 pc scale) regions of these galaxies are in some way related to the emission-line properties, which would imply a link between the stellar population and the i…
Mass segregation in young Magellanic Cloud star clusters: Four clusters observed with HST
Bellas-Velidis, I.; Kontizas, M.; Kontizas, E. +2 more
We present the results of our investigation on the phenomenon of mass segregation in young star clusters in the Magellanic Clouds. HST/WFPC2 observations on NGC 1818, NGC 2004 and NGC 2100 in the Large Magellanic Cloud and NGC 330 in the Small Magellanic Cloud have been used for the application of diagnostic tools for mass segregation: i) the radi…