Search Publications
Determination of the Coronal Magnetic Field from Hot-Loop Oscillations Observed by SUMER and SXT
Qiu, Jiong; Innes, Davina E.; Wang, Tongjiang
We apply a new method to determine the magnetic field in coronal loops, using observations of coronal loop oscillations. We analyze seven Doppler-shift oscillation events detected by SUMER in the hot flare line Fe XIX to obtain the oscillation periods of these events. The geometry, temperature, and electron density of the oscillating loops are mea…
The DEEP2 Galaxy Redshift Survey: AEGIS Observations of a Dual AGN at z = 0.7
Barmby, P.; Ivison, R. J.; Weiner, Benjamin J. +15 more
We present evidence of a dual active galactic nucleus (AGN) within an early-type galaxy at z=0.709 in the extended Groth strip. The galaxy lies on the red sequence, with absolute magnitude MB=-21.0 (AB, with h=0.7) and rest-frame color U-B=1.38. Its optical spectrum shows strong, double-peaked [O III] emission lines and weak Hβ emission…
Precise Timing of the X-ray Pulsar 1E 1207.4-5209: A Steady Neutron Star Weakly Magnetized at Birth
Gotthelf, E. V.; Halpern, J. P.
We analyze all X-ray timing data on 1E 1207.4-5209 in supernova remnant PKS 1209-51/52 gathered from 1993-2005 and find a highly stable rotation with P=424.130749(4) ms and P˙=(6.6+/-9.0)×10-17 (1 σ errors). This refutes previous claims of large timing irregularities in these data. In the dipole spin-down formalism, the 2 σ upper limit …
Coronal and Interplanetary Propagation of CME/Shocks from Radio, In Situ and White-Light Observations
Kaiser, M. L.; Bougeret, J. -L.; Reiner, M. J.
The kinematics of CMEs are well characterized to 32 Rsolar by height-time measurements from existing space-based and ground-based coronagraphs. Although there has been long-standing, but indirect, evidence that CMEs can exhibit significant deceleration as they propagate from Sun to Earth, the interplanetary kinematics of CMEs are not pr…
The Magnetic Topology of Coronal Mass Ejection Sources
Winebarger, Amy R.; Warren, Harry P.; Ugarte-Urra, Ignacio
In an attempt to test current initiation models of coronal mass ejections (CMEs), with an emphasis on the magnetic breakout model, we inspect the magnetic topology of the sources of 26 CME events in the context of their chromospheric and coronal response in an interval of approximately 9 hr around the eruption onset. First we perform current-free …
Large Amounts of Optically Obscured Star Formation in the Host Galaxies of Some Type 2 Quasars
Armus, L.; Seymour, N.; Canalizo, G. +5 more
We present Hubble Space Telescope images and spectral energy distributions from optical to infrared wavelengths for a sample of six 0.3<z<0.8 type 2 quasars selected in the mid-infrared using data from the Spitzer Space Telescope. All the host galaxies show some signs of disturbance. Most seem to possess dusty, star-forming disks. The disk i…
Stellar Kinematics in the Complicated Inner Spheroid of M31: Discovery of Substructure along the Southeastern Minor Axis and Its Relationship to the Giant Southern Stream
Gilbert, Karoline M.; Majewski, Steven R.; Guhathakurta, Puragra +9 more
We present the discovery of a kinematically cold stellar population along the southeastern minor axis of the Andromeda galaxy (M31) that is likely the forward continuation of M31's giant southern stream. This discovery was made during an on-going spectroscopic survey of M31 red giant branch (RGB) stars using the DEIMOS instrument on the Keck II 10…
The Distances to Open Clusters from Main-Sequence Fitting. IV. Galactic Cepheids, the LMC, and the Local Distance Scale
Pinsonneault, Marc H.; Terndrup, Donald M.; An, Deokkeun
We derive the basic properties of seven Galactic open clusters containing Cepheids and construct their period-luminosity (P-L) relations. For our cluster main-sequence fitting we extend previous Hyades-based empirical color-temperature corrections to hotter stars using the Pleiades as a template. We use BVICJHKs data to test …
Strong Dusty Bursts of Star Formation in Galaxies Falling into the Cluster RX J0152.7-1357
Rigby, J. R.; Rieke, G. H.; Marcillac, D. +1 more
We have observed the cluster RX J0152.7-1357 (z~0.83) at 24 µm with the Multiband Imaging Photometer for Spitzer (MIPS). We detected 22 sources associated with spectroscopically confirmed cluster members, while 10 more have photometric redshifts compatible with membership. Two of the 32 likely cluster members contain obvious active nuclei, w…
IR Observations of MS 1054-03: Star Formation and Its Evolution in Rich Galaxy Clusters
Tran, Kim-Vy H.; Rieke, George H.; Rieke, Marcia J. +6 more
We study the IR properties of galaxies in the cluster MS 1054-03 at z=0.83 by combining MIPS 24 µm data with spectra of more than 400 galaxies and a very deep K-band-selected catalog. Nineteen IR cluster members are selected spectroscopically, and an additional 15 are selected by their photometric redshifts. We derive the IR luminosity funct…