Search Publications
A First Look at the Auriga-California Giant Molecular Cloud with Herschel and the CSO: Census of the Young Stellar Objects and the Dense Gas
Matthews, Brenda C.; Bourke, Tyler L.; Di Francesco, James +7 more
We have mapped the Auriga/California molecular cloud with the Herschel PACS and SPIRE cameras and the Bolocam 1.1 mm camera on the Caltech Submillimeter Observatory with the eventual goal of quantifying the star formation and cloud structure in this giant molecular cloud (GMC) that is comparable in size and mass to the Orion GMC, but which appears…
An Initial Mass Function Study of the Dwarf Starburst Galaxy NGC 4214
O'Connell, R. W.; Calzetti, D.; Kennicutt, R. C. +11 more
The production rate of ionizing photons in young (<=8 Myr), unresolved stellar clusters in the nearby irregular galaxy NGC 4214 is probed using multi-wavelength Hubble Space Telescope WFC3 data. We normalize the ionizing photon rate by the cluster mass to investigate the upper end of the stellar initial mass function (IMF). We have found that w…
Herschel Far-infrared Spectroscopy of the Galactic Center. Hot Molecular Gas: Shocks versus Radiation near Sgr A*
Contursi, A.; Lis, D. C.; Bell, T. A. +10 more
We present a ~52-671 µm spectral scan toward Sgr A* taken with the PACS and SPIRE spectrometers on board Herschel. The achieved angular resolution allows us to separate, for the first time at far-IR wavelengths, the emission toward the central cavity (gas in the inner central parsec of the galaxy) from that of the surrounding circumnuclear d…
The Self-similarity of the Circumgalactic Medium with Galaxy Virial Mass: Implications for Cold-mode Accretion
Kacprzak, Glenn G.; Churchill, Christopher W.; Nielsen, Nikole M. +1 more
We apply halo abundance matching to obtain galaxy virial masses, M h, and radii, R vir, for 183 "isolated" galaxies from the "Mg II Absorber-Galaxy Catalog." All galaxies have spectroscopic redshifts (0.07 <= z <= 1.12) and their circumgalactic medium (CGM) is probed in Mg II absorption within projected galactocentric …
Predictions of Ion Production Rates and Ion Number Densities within the Diamagnetic Cavity of Comet 67P/Churyumov-Gerasimenko at Perihelion
Vigren, E.; Galand, M.
We present a one-dimensional ion chemistry model of the diamagnetic cavity of comet 67P/Churyumov-Gerasimenko, the target comet for the ESA Rosetta mission. We solve the continuity equations for ionospheric species and predict number densities of electrons and selected ions considering only gas-phase reactions. We apply the model to the subsolar d…
The High-latitude Branch of the Solar Torsional Oscillation in the Rising Phase of Cycle 24
Thompson, M. J.; Howe, R.; Komm, R. +5 more
We use global heliseismic data from the Global Oscillation Network Group, the Michelson Doppler Imager on board the Solar and Heliospheric Observatory, and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, to examine the behavior, during the rising phase of Solar Cycle 24, of the migrating zonal flow pattern known as th…
Discovery of GeV Emission from the Circinus Galaxy with the Fermi Large Area Telescope
Stawarz, Łukasz; Madejski, Greg M.; Cheung, Chi C. +7 more
We report the discovery of γ-ray emission from the Circinus galaxy using the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. Circinus is a nearby (~4 Mpc) starburst with a heavily obscured Seyfert-type active nucleus, bipolar radio lobes perpendicular to the spiral disk, and kpc-scale jet-like structures. Our analysis of 0…
The Morphology of the Ejecta in Supernova 1987A: A Study over Time and Wavelength
Fransson, Claes; Kirshner, Robert P.; Leibundgut, Bruno +9 more
We present a study of the morphology of the ejecta in Supernova 1987A based on images and spectra from the Hubble Space Telescope (HST) as well as integral field spectroscopy from VLT/SINFONI. The HST observations were obtained between 1994 and 2011 and primarily probe the outer H-rich zones of the ejecta. The SINFONI observations were obtained in…
Testing Galaxy Formation Models with the GHOSTS Survey: The Color Profile of M81's Stellar Halo
Bell, Eric F.; Holwerda, Benne W.; Monachesi, Antonela +6 more
We study the properties of the stellar populations in M81's outermost part, which hereafter we will call the stellar halo, using Hubble Space Telescope (HST) Advanced Camera for Surveys observations of 19 fields from the GHOSTS survey. The observed fields probe the stellar halo out to a projected distance of ~50 kpc from the galactic center. Each …
Confirmation of Small Dynamical and Stellar Masses for Extreme Emission Line Galaxies at z ~ 2
Bell, Eric F.; Grogin, Norman A.; Kocevski, Dale D. +21 more
Spectroscopic observations from the Large Binocular Telescope and the Very Large Telescope reveal kinematically narrow lines (~50 km s-1) for a sample of 14 extreme emission line galaxies at redshifts 1.4 < z < 2.3. These measurements imply that the total dynamical masses of these systems are low (lsim 3 × 109 M ⊙<…