Search Publications
A Slow Merger History of Field Galaxies since z ~ 1
Conselice, Christopher J.; Ellis, Richard S.; Kodama, Tadayuki +2 more
Using deep infrared observations conducted with the CISCO imager on the Subaru Telescope, we investigate the field-corrected pair fraction and the implied merger rate of galaxies in redshift survey fields with Hubble Space Telescope (HST) imaging. In the redshift interval, 0.5<z<1.5, the fraction of infrared-selected pairs increases only mod…
The Optical Counterpart of an Ultraluminous X-Ray Source in NGC 5204
Bregman, Joel N.; Seitzer, Patrick; Liu, Ji-Feng
Ultraluminous X-ray (ULX) sources are extranuclear point sources in external galaxies with LX=1039-1041 ergs s-1 and are among the most poorly understood X-ray sources. To help understand their nature, we are trying to identify their optical counterparts by combining images from the Hubble Space Telescop…
FUSE and STIS Observations of the Warm-hot Intergalactic Medium toward PG 1259+593
Richter, Philipp; Tripp, Todd M.; Sembach, Kenneth R. +1 more
We use Far Ultraviolet Spectroscopic Explorer (FUSE) and Space Telescope Imaging Spectrograph (STIS) spectra to study intergalactic absorption toward the quasar PG 1259+593 (zem=0.478), with a particular emphasis on the warm-hot intergalactic medium (WHIM). The combined FUSE and STIS spectrum of PG 1259+593 covers the full wavelength ra…
Flare Ribbon Expansion and Energy Release Rate
Shibata, Kazunari; Masuda, Satoshi; Shimojo, Masumi +3 more
We have examined the relation between the evolution of the Hα flare ribbons and the released magnetic energy in a solar flare that occurred on 2001 April 10. Based on the magnetic reconnection model, the released energy was quantitatively calculated by using the photospheric magnetic field strengths and separation speeds of the fronts of the Hα fl…
The 2003 shell event in η Carinae
Breedt, Elmé; Whitelock, Patricia A.; Feast, Michael W. +1 more
Near-infrared, JHKL, photometry of η Car is reported covering the period 2000-2004. This includes the 2003 shell event which was the subject of an international multiwavelength campaign. The fading that accompanied this event was similar to, although slightly deeper than, that which accompanied the previous one. The period between these events is …
CME-Flare Association Deduced from Catastrophic Model of CMEs
Lin, Jun
Based on our previous works regarding solar eruptions, we focus on the relationships among different eruptive phenomena, such as solar flares, eruptive prominences and coronal mass ejections (CMEs). The three processes show clear correlations under certain circumstances. The correlation between a CME and solar flare depends the energy that stored …
On a Surge: Properties of an Emerging Flux Region
Liu, Yu; Kurokawa, Hiroki
A surge event with multi-instrument and multiwavelength observations is presented. The event occurred in a surge-productive region on 2001 August 30. TRACE white-light images, Huairou vector magnetograms, and Hβ filtergrams show that this surge was closely associated with new bipoles that emerged in 1 hr. Evidence of enhanced magnetic cancellation…
The Deep Lens Survey Transient Search. I. Short Timescale and Astrometric Variability
Becker, A. C.; Frail, D. A.; Halpern, J. +8 more
We report on the methodology and first results from the Deep Lens Survey (DLS) transient search. We utilize image subtraction on survey data to yield all sources of optical variability down to 24th magnitude. Images are analyzed immediately after acquisition, at the telescope, and in near-real time, to allow for follow-up in the case of time-criti…
Morphologies and Spectral Energy Distributions of Extremely Red Galaxies in the GOODS-South Field
Papovich, Casey; Ferguson, Henry C.; Giavalisco, Mauro +12 more
Using U'- through Ks-band imaging data in the Great Observatories Origins Deep Survey-South (GOODS-South) field, we construct a large, complete sample of 275 extremely red objects (EROs; Ks<22.0, R-Ks>3.35 AB), all with deep Hubble Space Telescope Advanced Camera for Surveys imaging in B435
On the origin of the C IV Baldwin effect in active galactic nuclei
Laor, Ari; Baskin, Alexei
The origin of the luminosity dependence of the equivalent width (EW) of broad emission lines in active galactic nuclei (AGN) - the Baldwin effect - is not firmly established yet. We explore this question for the broad C IVλ1549 line using the Boroson & Green sample of the 87 z<= 0.5 Bright Quasar Survey (BQS) quasars. Useful UV spectra of t…