Search Publications
A High-resolution Mid-infrared Survey of Water Emission from Protoplanetary Disks
Zhang, Ke; Lacy, John; Najita, Joan R. +5 more
We present the largest survey of spectrally resolved mid-infrared water emission to date, with spectra for 11 disks obtained with the Michelle and TEXES spectrographs on Gemini North. Water emission is detected in six of eight disks around classical T Tauri stars. Water emission is not detected in the transitional disks SR 24 N and SR 24 S, in spi…
High-velocity outflows in massive post-starburst galaxies at z > 1
Castellano, Marco; Koekemoer, Anton M.; Pentericci, Laura +21 more
We investigate the prevalence of galactic-scale outflows in post-starburst (PSB) galaxies at high redshift (1 < z < 1.4), using the deep optical spectra available in the UKIDSS Ultra Deep Survey (UDS). We use a sample of ∼40 spectroscopically confirmed PSBs, recently identified in the UDS field, and perform a stacking analysis in order to an…
Ruprecht 147 DANCe. I. Members, empirical isochrone, luminosity, and mass distributions
Tamura, M.; Bertin, E.; Miret-Roig, N. +10 more
Context. Ruprecht 147 is the oldest (2.5 Gyr) open cluster in the solar vicinity (< 300 pc), making it an important target for stellar evolution studies and exoplanet searches.
Aims: We aim to derive a census of members and the luminosity, mass, and spatial distributions of the cluster.
Methods: We used an astro-photometric data set i…
The COMBS survey - I. Chemical origins of metal-poor stars in the Galactic bulge
Kobayashi, Chiaki; Marino, Anna F.; Hawkins, Keith +7 more
Chemistry and kinematic studies can determine the origins of stellar population across the Milky Way. The metallicity distribution function of the bulge indicates that it comprises multiple populations, the more metal-poor end of which is particularly poorly understood. It is currently unknown if metal-poor bulge stars ([Fe/H] <-1 dex) are part…
The Mass-Activity Relationships in M and K Dwarfs. I. Stellar Parameters of Our Sample of M and K Dwarfs
Doyle, J. G.; Mullan, D. J.; Butler, C. J. +3 more
Empirical correlations between stellar parameters such as rotation or radius and magnetic activity diagnostics require estimates of the effective temperatures and the stellar radii. The aim of this study is to propose simple methods that can be applied to large samples of stars in order to derive estimates of the stellar parameters. Good empirical…
The ACS Fornax Cluster Survey. III. Globular Cluster Specific Frequencies of Early-type Galaxies
Jordán, Andrés; Côté, Patrick; Peng, Eric W. +4 more
The globular cluster (GC) specific frequency (S N ), defined as the number of GCs per unit galactic luminosity, represents the efficiency of GC formation (and survival) compared to field stars. Despite the naive expectation that star cluster formation should scale directly with star formation, this efficiency varies widely across galax…
Variable emission mechanism of a Type IV radio burst
Kilpua, E. K. J.; Monstein, C.; Morosan, D. E. +1 more
Context. The Sun is an active star and the source of the largest explosions in the solar system, such as flares and coronal mass ejections (CMEs). Flares and CMEs are powerful particle accelerators that can generate radio emission through various emission mechanisms.
Aims: CMEs are often accompanied by Type IV radio bursts that are observed a…
Cool circumgalactic gas of passive galaxies from cosmological inflow
Afruni, Andrea; Fraternali, Filippo; Pezzulli, Gabriele
The circumgalactic medium (CGM) of galaxies consists of a multi-phase gas with components at very different temperatures, from 104 K to 107 K. One of the greatest puzzles about this medium is the presence of a large amount of low-temperature (T ∼ 104 K) gas around quiescent early-type galaxies (ETGs). Using semi-an…
Implications of a Time-varying Galactic Potential for Determinations of the Dynamical Surface Density
Hernquist, Lars; Famaey, Benoit; Haines, Tim +2 more
We analyze a high-resolution N-body simulation of a live stellar disk perturbed by the recent passage of a massive dwarf galaxy that induces a wobble, in-plane rings, and phase spirals in the disk. The implications of the phase-space structures and the estimate of the matter density through traditional Jeans modeling are investigated. The dwarf sa…
The Effects of Solar Wind Dynamic Pressure on the Structure of the Topside Ionosphere of Mars
Gurnett, D. A.; Morgan, D. D.; Kopf, A. J. +3 more
We use Mars Atmosphere and Volatile EvolutioN observations of the upstream solar wind, and Mars Express observations of ionospheric electron densities and magnetic fields, to study how the topside ionosphere (>320 km) of Mars is affected by variations in solar wind dynamic pressure. We find that high solar wind dynamic pressures result in the t…