Search Publications
On the Evolution of the Molecular Gas Fraction of Star-Forming Galaxies
Smail, Ian; Moran, Sean M.; MacArthur, Lauren A. +3 more
We present IRAM Plateau de Bure interferometric detections of CO (J = 1 → 0) emission from a 24 µm-selected sample of star-forming galaxies at z = 0.4. The galaxies have polycyclic aromatic hydrocarbon 7.7 µm-derived star formation rates of SFR ~30-60 M sun yr-1 and stellar masses M sstarf ~ 1011
Globular Clusters in the Outer Galactic Halo: New Hubble Space Telescope/Advanced Camera for Surveys Imaging of Six Globular Clusters and the Galactic Globular Cluster Age-metallicity Relation
Anderson, Jay; Dotter, Aaron; Sarajedini, Ata
Color-magnitude diagrams (CMDs) derived from Hubble Space Telescope (HST) Advanced Camera for Surveys F606W, F814W photometry of six globular clusters (GCs) are presented. The six GCs form two loose groupings in Galactocentric distance (R GC): IC 4499, NGC 6426, and Ruprecht 106 at ~15-20 kpc and NGC 7006, Palomar 15, and Pyxis at ~40 k…
Observing Flux Rope Formation During the Impulsive Phase of a Solar Eruption
Liu, Y.; Cheng, X.; Ding, M. D. +1 more
Magnetic flux ropes are believed to be an important structural component of coronal mass ejections (CMEs). While there exists much observational evidence of flux ropes after the eruption, e.g., as seen in remote-sensing coronagraph images or in situ solar wind data, the direct observation of flux ropes during CME impulsive phase has been rare. In …
Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey
Oyabu, Shinki; Hasegawa, Sunao; Onaka, Takashi +10 more
We present the results of an unbiased asteroid survey in the mid-infrared wavelength region with the Infrared Camera (IRC) on board the Japanese infrared satellite AKARI. About 20% of the point source events recorded in the AKARI All-Sky Survey observations are not used for the IRC Point Source Catalog (IRC-PSC) in its production process because o…
Planck early results. XXIV. Dust in the diffuse interstellar medium and the Galactic halo
Kneissl, R.; Miville-Deschênes, M. -A.; Boulanger, F. +205 more
This paper presents the first results from a comparison of Planck dust maps at 353, 545 and 857GHz, along with IRAS data at 3000 (100 µm) and 5000GHz (60 µm), with Green Bank Telescope 21-cm observations of Hi in 14 fields covering more than 800 deg2 at high Galactic latitude. The main goal of this study is to estimate the f…
What Drives the Expansion of Giant H II Regions?: A Study of Stellar Feedback in 30 Doradus
Ramirez-Ruiz, Enrico; Prochaska, J. Xavier; Bolatto, Alberto D. +2 more
Observations show that star formation is an inefficient and slow process. This result can be attributed to the injection of energy and momentum by stars that prevents free-fall collapse of molecular clouds. The mechanism of this stellar feedback is debated theoretically; possible sources of pressure include the classical warm H II gas, the hot gas…
Non-standard grain properties, dark gas reservoir, and extended submillimeter excess, probed by Herschel in the Large Magellanic Cloud
Bernard, J. -P.; Reach, W. T.; Lebouteiller, V. +13 more
Context.Herschel provides crucial constraints on the IR SEDs of galaxies, allowing unprecedented accuracy on the dust mass estimates. However, these estimates rely on non-linear models and poorly-known optical properties.
Aims: In this paper, we perform detailed modelling of the Spitzer and Herschel observations of the LMC, in order to: (i) s…
The causal connection between disc and power-law variability in hard state black hole X-ray binaries
Wilms, J.; Uttley, P.; Pottschmidt, K. +4 more
We use the XMM-Newton EPIC-pn instrument in timing mode to extend spectral time-lag studies of hard state black hole X-ray binaries into the soft X-ray band. We show that variations of the disc blackbody emission substantially lead variations in the power-law emission, by tenths of a second on variability time-scales of seconds or longer. The larg…
Photospheric flux cancellation and associated flux rope formation and eruption
Green, L. M.; Kliem, B.; Wallace, A. J.
Aims: We study an evolving bipolar active region that exhibits flux cancellation at the internal polarity inversion line, the formation of a soft X-ray sigmoid along the inversion line and a coronal mass ejection. The aim is to investigate the quantity of flux cancellation that is involved in flux rope formation in the time period leading up …
Sizes and Temperature Profiles of Quasar Accretion Disks from Chromatic Microlensing
Schechter, Paul L.; Pooley, David; Blackburne, Jeffrey A. +1 more
Microlensing perturbations to the flux ratios of gravitationally lensed quasar images can vary with wavelength because of the chromatic dependence of the accretion disk's apparent size. Multiwavelength observations of microlensed quasars can thus constrain the temperature profiles of their accretion disks, a fundamental test of an important astrop…