Search Publications
The Herschel Filament: A Signature of the Environmental Drivers of Galaxy Evolution during the Assembly of Massive Clusters at z = 0.9
Egami, E.; Yee, H. K. C.; Gladders, M. +11 more
We have discovered a 2.5 Mpc (projected) long filament of infrared-bright galaxies connecting two of the three ~5 × 1014 M ⊙ clusters making up the RCS 2319+00 supercluster at z = 0.9. The filament is revealed in a deep Herschel Spectral and Photometric Imaging REceiver (SPIRE) map that shows 250-500 µm emission associa…
Measuring the Geometry of the Universe from Weak Gravitational Lensing behind Galaxy Groups in the HST COSMOS Survey
Koekemoer, Anton M.; Ellis, Richard; Leauthaud, Alexie +12 more
Gravitational lensing can provide pure geometric tests of the structure of spacetime, for instance by determining empirically the angular diameter distance-redshift relation. This geometric test has been demonstrated several times using massive clusters which produce a large lensing signal. In this case, matter at a single redshift dominates the l…
Subsurface Flows in and Around Active Regions with Rotating and Non-rotating Sunspots
Hill, F.; González Hernández, I.; Komm, R. W. +2 more
The temporal variation of the horizontal velocity in sub-surface layers beneath three different types of active region is studied using the technique of ring diagrams. In this study, we select active regions (ARs) 10923, 10930, 10935 from three consecutive Carrington rotations: AR 10930 contains a fast-rotating sunspot in a strong emerging active …
XMM-Newton Observation of the Very Old Pulsar J0108-1431
Manchester, R. N.; Pavlov, G. G.; Shannon, R. M. +3 more
We report on an X-ray observation of the 166 Myr old radio pulsar J0108-1431 with XMM-Newton. The X-ray spectrum can be described by a power-law model with a relatively steep photon index Γ ≈ 3 or by a combination of thermal and non-thermal components, e.g., a power-law component with fixed photon index Γ = 2 plus a blackbody component with a temp…
In the whirlpool's coils: tracing substructure from combined optical/X-ray data in the galaxy cluster A1300
Finoguenov, A.; Böhringer, H.; Ziparo, F. +3 more
Structure formation is thought to act via hierarchical mergers and accretion of smaller systems driven by gravity, with dark matter dominating the gravitational field. Combining X-ray and optical imaging and spectroscopy provides a powerful approach to the study of the cluster dynamics and mass assembly history. The ROSAT-ESO Flux Limited X-ray (R…
Hα star formation rates in massive galaxies at z∼ 1
Weiner, Benjamin J.; Conselice, Christopher J.; Bauer, Amanda E. +4 more
We present a near-infrared spectroscopic study of a stellar mass selected sample of galaxies at z∼ 1 utilizing the Long-slit Intermediate Resolution Infrared Spectrograph multi-object spectrograph on the William Herschel Telescope. We detect continuum, and the Hα line for our sample, which is one of the better direct tracers of star formation in e…
Dependence of kinematics on the age of stars in the solar neighborhood
Gontcharov, G. A.
The variations of kinematic parameters with age are considered for a sample of 15 402 thin-disk O-F stars with accurate α, δ, µ, and π > 3 mas from the Hipparcos catalogue and radial velocities from the PCRV catalogue. The ages have been calculated from the positions of the stars on the Hertzsprung-Russell diagram relative to the isochrones fro…
Geometry of the 20 November 2003 magnetic cloud
Park, Sung-Hong; Cho, Kyung-Suk; Kim, Yeon-Han +2 more
This study is an attempt to find a coherent interpretation of the link between the 20 November 2003 magnetic cloud (MC) and its solar source. Most previous studies agree on the orientation of the MC, but the orientation is nearly perpendicular to the axis of the post-eruption arcade (PEA) or the orientation of the neutral line in the solar source …
Spectral comparison of weak short bursts to the persistent X-rays from the magnetar 1E 1547.0-5408 in its 2009 outburst
Sakamoto, T.; Enoto, T.; Makishima, K. +1 more
In 2009 January, the 2.1-s anomalous X-ray pulsar 1E 1547.0-5408 evoked intense burst activity. A follow-up Suzaku observation on January 28 recorded enhanced persistent emission in both soft and hard X-rays. Through a reanalysis of the same Suzaku data, 18 short bursts were identified in the X-ray events recorded by the Hard X-ray Detector (HXD) …
Black-hole-Bulge Relationship of Post-starburst Quasars at z ~ 0.3
Canalizo, Gabriela; Brotherton, Michael S.; Cales, Sabrina L. +2 more
The M BH-σ* relation has been studied extensively for local galaxies, but to date there have been scarce few direct measurements of stellar velocity dispersions for systems beyond the local universe. We investigate black hole and host galaxy properties of six "post-starburst quasars" (PSQs) at z ~ 0.3. Spectra of these object…