Search Publications
Probing AGN triggering mechanisms through the starburstiness of the host galaxies
Fiore, F.; Piconcelli, E.; Santini, P. +3 more
We estimate the fraction of AGNs hosted in starburst galaxies (fbursty) as a function of the AGN luminosity predicted under the assumption that starburst events and AGN activity are triggered by galaxy interactions during their merging histories. The latter are described through Monte Carlo realizations, and are connected to star format…
Hubble Space Telescope and Ground-based Observations of V455 Andromedae Post-outburst
Szkody, Paula; Sion, Edward M.; Gänsicke, Boris T. +8 more
Hubble Space Telescope spectra obtained in 2010 and 2011, 3 and 4 yr after the large amplitude dwarf nova outburst of V455 And, were combined with optical photometry and spectra to study the cooling of the white dwarf, its spin, and possible pulsation periods after the outburst. The modeling of the ultraviolet (UV) spectra shows that the white dwa…
Deep optical imaging of asymptotic giant branch circumstellar envelopes
Mauron, N.; Huggins, P. J.; Cheung, C. -L.
We report results of a program to image the extended circumstellar envelopes of asymptotic giant branch (AGB) stars in dust-scattered Galactic light. The goal is to characterize the shapes of the envelopes to probe the mass-loss geometry and the presence of hidden binary companions. The observations consist of deep optical imaging of 22 AGB stars …
Triggered/sequential star formation? A multi-phase ISM study around the prominent IRDC G18.93-0.03
Henning, T.; Beuther, H.; Plume, R. +5 more
Context. Triggered star formation has been discussed for many years, and evidence for the formation of stars and cores triggered by Hii regions is under debate.
Aims: We investigate the imprints of an expanding Hii region on a pre-existing starless clumps.
Methods: We selected an infrared dark filament spanning 0.8°. One portion of this …
The spectrum of kink-like oscillations of solar photospheric magnetic elements
Berrilli, F.; Consolini, G.; Stangalini, M.
Recently, the availability of new high spatial and temporal resolution observations of the solar photosphere has allowed for the study of the oscillations in small magnetic elements. Small magnetic elements have been found to host a rich variety of oscillations detectable as intensity, longitudinal, or transverse velocity fluctuations that have be…
Suzaku Observations of the Type 2 QSO in the Central Galaxy of the Phoenix Cluster
Koyama, Katsuji; Hayashida, Kiyoshi; Nakajima, Hiroshi +3 more
We report the Suzaku/XIS and HXD and Chandra/ACIS-I results on the X-ray spectra of the Phoenix cluster at the redshift z = 0.596. The spectrum of the intracluster medium (ICM) is well reproduced with the emissions from low-temperature (~3.0 keV and ~0.76 solar) and high-temperature (~11 keV and ~0.33 solar) plasmas; the former is localized at the…
Origin of the Dense Core Mass Function in Contracting Filaments
Myers, Philip C.
Mass functions of starless dense cores (CMFs) may arise from contraction and dispersal of core-forming filaments. In an illustrative model, a filament contracts radially by self-gravity, increasing the mass of its cores. During this contraction, FUV photoevaporation and ablation by shocks and winds disperse filament gas and limit core growth. The …
Resonant diffusion of energetic electrons by narrowband Z mode waves in Saturn's inner magnetosphere
Ni, Binbin; Gu, Xudong; Ye, Sheng-Yi +1 more
<title type="main">Abstract<p label="1">Banded emissions near 5 and 20 kHz are observed by the Cassini Radio and Plasma Wave Science (RPWS) instrument and are identified as Z mode waves in the regions where the plasma frequency is below the electron gyrofrequency. Using wave parameters derived from Gaussian fits to the measured power s…
Spectral analysis for wide energy channels
Daly, P. W.; Kronberg, E. A.
For energetic particle measurements whose spectra follow a power law, it is often challenging to define a characteristic ("effective") energy of an energy channel. In order to avoid time-consuming calculations, the geometric mean is often used as an approximation for the effective energy. This approximation is considered to be pretty good. It is, …
The ACS Virgo Cluster Survey. XVII. The Spatial Alignment of Globular Cluster Systems with Early-type Host Galaxies
Jordán, Andrés; Côté, Patrick; Peng, Eric W. +5 more
We study the azimuthal distribution of globular clusters (GCs) in early-type galaxies and compare them to their host galaxies using data from the ACS Virgo Cluster Survey. We find that in host galaxies with visible elongation (epsilon > 0.2) and intermediate to high luminosities (Mz < -19), the GCs are preferentially aligned along…