Search Publications
The supermassive black hole in NGC4486a detected with SINFONI at the Very Large Telescope
Pannella, M.; Saglia, R. P.; Nowak, N. +4 more
The near-infrared (IR) integral field spectrograph SINFONI at the European Southern Observatory Very Large Telescope opens a new window for the study of central supermassive black holes. With a near-IR spatial resolution similar to Hubble Space Telescope optical and the ability to penetrate dust, it provides the possibility to explore the low-mass…
The Stellar Populations in the Outer Regions of M33. III. Star Formation History
Sarajedini, Ata; Schommer, Robert; Geisler, Doug +2 more
We present a detailed analysis of the star formation history (SFH) of three fields in M33 located approximately four to six visual scale lengths from its nucleus. These fields were imaged with the Advanced Camera for Surveys on the Hubble Space Telescope and reach ~2.5 mag below the red clump of core helium-burning stars. The observed color-magnit…
Gamma-ray emission from massive young stellar objects
Paredes, J. M.; Romero, G. E.; Bosch-Ramon, V. +1 more
Context: Massive stars form in dense and massive molecular cores. The exact formation mechanism is unclear, but it is possible that some massive stars are formed by processes similar to those that produce the low-mass stars, with accretion/ejection phenomena occurring at some point of the evolution of the protostar. This picture seems to be suppor…
Low-Energy Cutoffs and Hard X-Ray Spectra in High-z Radio-loud Quasars: The Suzaku View of RBS 315
Maraschi, L.; Tagliaferri, G.; Ghisellini, G. +4 more
We present the results from the Suzaku observation of the powerful radio-loud quasar RBS 315 (z=2.69), for which a previous XMM-Newton observation showed an extremely flat X-ray continuum up to 10 keV (photon index Γ=1.26) and indications of strong intrinsic absorption (NH~1022 cm-2, assuming neutral gas). The inst…
Bayesian Single-Epoch Photometric Classification of Supernovae
Maoz, Dan; Gal-Yam, Avishay; Poznanski, Dovi
Ongoing supernova (SN) surveys find hundreds of candidates that require confirmation for their various uses. Traditional classification based on follow-up spectroscopy of all candidates is virtually impossible for these large samples. The use of Type Ia SNe as standard candles is at an evolved stage that requires pure, uncontaminated samples. Howe…
Electrons and Protons in Solar Energetic Particle Events
Ling, A. G.; Cliver, E. W.
A plot of 0.5 MeV peak electron intensity versus >10 MeV peak proton intensity for well-connected solar energetic particle (SEP) events from 1997 to 2003 reveals two distinct populations: (1) a group of events with peak proton intensities <3 protons cm-2 s-1 sr-1 that have electron-to-proton (e/p) ratios rang…
Assessing the limits of the Modified Gaussian Model for remote spectroscopic studies of pyroxenes on Mars
Mustard, John F.; Gendrin, Aline; Kanner, Lisa C.
We investigate the ability to refine pyroxene composition and modal abundance from laboratory and remotely acquired spectra. Laboratory data including the martian meteorites, Shergotty, Zagami, MIL03346, and ALH84001 as well as additional pyroxene-rich spectra obtained from the OMEGA (Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activ…
Unveiling the oldest and most massive galaxies at very high redshift
Cimatti, A.; Rodighiero, G.; Bolzonella, M. +3 more
Context: The identification and characterisation of massive galaxies over a wide redshift range allow us to place stringent constraints on the cosmic history of galaxy mass assembly and on current models of galaxy formation and evolution.
Aims: This work explores the existence of high-redshift massive galaxies unveiled with Spitzer+IRAC, but m…
Swift XRT Observation of 34 New INTEGRAL IBIS AGNs: Discovery of Compton-Thick and Other Peculiar Sources
Gehrels, N.; Bird, A. J.; Fiocchi, M. +7 more
For a significant number of the sources detected at high energies (>10 keV) by the INTEGRAL IBIS and Swift BAT instruments there is either a lack information about them in the 2-10 keV range or they are totally unidentified. Herein, we report on a sample of 34 IBIS AGNs or AGN candidate objects for which there is X-ray data in the Swift XRT arc…
Analysis of a giant lightning storm on Saturn
Gurnett, D. A.; Kurth, W. S.; Fischer, G. +5 more
On January 23, 2006, the Cassini/RPWS (Radio and Plasma Wave Science) instrument detected a massive outbreak of SEDs (Saturn Electrostatic Discharges). The following SED storm lasted for about one month and consisted of 71 consecutive episodes. It exceeded all other previous SED observations by Cassini as well as by the Voyagers with regard to num…