Search Publications
The Nature of Near-Ultraviolet-selected Objects in the Chandra Deep Field-South
Gardner, Jonathan P.; Koekemoer, A. M.; Conselice, C. J. +3 more
We present the first results of the pure parallel near-UV observations with the Wide Field Planetary Camera 2 (WFPC2) in the Chandra Deep Field-South. The main goal is to search for the population of objects that contributes to the rise in the volume-averaged star formation rate at intermediate redshifts (z<1). A total of 34 objects were identi…
The Counterarc to MS 1512-cB58 and a Companion Galaxy
Teplitz, Harry I.; Malkan, Matthew A.; McLean, Ian S.
We present near-infrared spectra of ``A2,'' the primary counterarc to the gravitationally lensed galaxy MS 1512-cB58. The spectra show redshifted Hα, [N II], [O III], and Hβ at z=2.729+/-0.001. We observe the same Hα/[O III] ratio as cB58, which together with the redshift confirms that A2 is indeed another image of a single background galaxy. Publ…
Stereoscopic Spectroscopy for Efficient Spectral Imaging and Magnetography
DeForest, Craig; Elmore, D. F.; Bradford, M. P. +2 more
Stereoscopic imaging spectroscopy is a novel technique that uses multiple spectral orders and stereoscopic reconstruction to eliminate the need for a slit in a dispersive spectrograph, potentially increasing photon efficiency by 1-2 orders of magnitude compared with conventional spectral imaging. We present advances in stereoscopic reconstruction,…
The Additional Line Component within the Iron Kα Profile in MCG -6-30-15: Evidence for Blob Ejection?
Qu, Jin-Lu; Wang, Jian-Min; Xue, Sui-Jian
The EPIC data of MCG -6-30-15 observed by XMM-Newton were analyzed for the complexities of the iron Kα line. Here we report that the additional line component (ALC) at 6.9 keV undoubtedly appears within the broad iron Kα line profile at the high state, whereas it disappears at the low state. These state-dependent behaviors exclude several possible…
The Aligned z~1 Radio Galaxy 3C 280
Lacy, Mark; Stockton, Alan; Ridgway, Susan E.
The z~1 radio galaxy 3C 280 has a particularly striking rest-frame UV morphology, with multiple line and continuum components precisely aligned with the radio structure, including an obvious semicircular arc. Here we explore the nature of these various components by bringing together Hubble Space Telescope and ground-based imaging, ground-based sp…
Detailed SUMER Observations of Coronal Loop Footpoint Dynamics
McIntosh, Scott W.; Poland, Arthur I.
For the most part, the characteristics of heating in the open corona and in closed coronal loops are determined by observing the emitted plasma intensity as a function of position and comparing this with model calculations. There are also some efforts that include observed velocity and still others that use theoretical physical processes such as e…
Optimal Galaxy Shape Measurements for Weak Lensing Applications Using the Hubble Space Telescope Advanced Camera for Surveys
Ferguson, Henry C.; Casertano, Stefano; Park, Yousin
We present three-epoch multiband (V606, i775, and z850) measurements of galaxy shapes using the ``polar shapelet'' or Laguerre expansions method with the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) data, obtained as part of the Great Observatories Origin Deep Survey (GOODS). We take advantage of …
Flickering Red Giants in the Ursa Minor Dwarf Spheroidal Galaxy: Detection of Low-Amplitude Variability in Faint Red Giant Branch Stars on 10 Minute Timescales
Roederer, Ian U.; Mighell, Kenneth J.
We have analyzed two epochs of Hubble Space Telescope Wide Field Planetary Camera 2 observations of the Ursa Minor dwarf spheroidal galaxy using the HSTphot photometric reduction package. We report the detection of nine faint (MV>~0.0 mag) red giant variable stars that exhibit low-amplitude brightness fluctuations on 10 minute timesc…
Far Ultraviolet Spectroscopic Explorer Observations of the Dwarf Nova SW Ursae Majoris during Quiescence
Raymond, J. C.; Lobel, A.; Menou, K. +1 more
We present spectroscopic observations of the short-period cataclysmic variable SW UMa obtained by the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite while the system was in quiescence. The data include the resonance lines of O VI at 1031.91 and 1037.61 Å. These lines are present in emission, and they exhibit both narrow (~150 km s-1<…
A Search for Short-Timescale Microvariability in Active Galactic Nuclei in the Ultraviolet
Dolan, Joseph F.; Clark, L. Lee
We observed four active galactic nuclei (AGNs) (the type 1 Seyfert systems 3C 249.1, NGC 6814, and Mrk 205, and the BL Lac object 3C 371) using the High Speed Photometer on the Hubble Space Telescope (HST) to search for short-timescale microvariability in the UV. Continuous observations of ~3000 s duration were obtained for each system on several …