Search Publications
Is FS Tau B Driving an Asymmetric Jet?
Ohashi, Nagayoshi; Pyo, Tae-Soo; Liu, Chun-Fan +6 more
FS Tau B is one of the few T Tauri stars that possess a jet and a counterjet as well as an optically visible cavity wall. We obtained images and spectra of its jet-cavity system in the near-infrared H and K bands using the Subaru/Infrared Camera and Spectrograph and detected the jet and the counterjet in the [Fe II] 1.644 µm line for the fir…
Inverse Compton X-Ray Halos around High-z Radio Galaxies: A Feedback Mechanism Powered by Far-infrared Starbursts or the Cosmic Microwave Background?
Lehmer, B. D.; Smail, Ian; Alexander, D. M. +1 more
We report the detection of extended X-ray emission around two powerful radio galaxies at z ~ 3.6 (4C 03.24 and 4C 19.71) and use these to investigate the origin of extended, inverse Compton (IC) powered X-ray halos at high redshifts. The halos have X-ray luminosities of L X ~ 3 × 1044 erg s-1 and sizes of ~60 kpc. …
The ChaMPlane Bright X-Ray Sources—Galactic Longitudes l = 2°-358°
Penner, Kyle; Laycock, Silas; van den Berg, Maureen +4 more
The Chandra Multi-wavelength Plane (ChaMPlane) survey aims to constrain the Galactic population of mainly accretion-powered, but also coronal, low-luminosity X-ray sources (L X <~ 1033 erg s-1). To investigate the X-ray source content in the plane at fluxes F X >~ 3 × 10-14 erg s-1<…
DASCH Discovery of a Possible Nova-like Outburst in a Peculiar Symbiotic Binary
Quinn, Samuel N.; Orosz, Jerome A.; Grindlay, Jonathan E. +4 more
We present photometric and spectroscopic observations of a peculiar variable (designated DASCH J075731.1+201735 or J0757) discovered from our DASCH project using the digitized Harvard College Observatory archival photographic plates. It brightened by about 1.5 mag in B within a year starting in 1942, and then slowly faded back to its pre-outburst …
The Spindle: An Irradiated Disk and Bent Protostellar Jet in Orion
Ginsburg, Adam; Youngblood, Allison; Bally, John
We present Hubble Space Telescope observations of a bent, pulsed Herbig-Haro jet, HH 1064, emerging from the young star Parenago 2042 embedded in the H II region NGC 1977 located about 30' north of the Orion Nebula. This outflow contains eight bow shocks in the redshifted western lobe and five bow shocks in the blueshifted eastern lobe. Shocks wit…
Abell 1201: A Minor Merger at Second Core Passage
McNamara, Brian R.; Nulsen, Paul E. J.; Murray, Stephen S. +3 more
We present an analysis of the structures and dynamics of the merging cluster Abell 1201, which has two sloshing cold fronts around a cooling core, and an offset gas core approximately 500 kpc northwest of the center. New Chandra and XMM-Newton data reveal a region of enhanced brightness east of the offset core, with breaks in surface brightness al…
Magnetic Helicity Transported by Flux Emergence and Shuffling Motions in Solar Active Region NOAA 10930
Zhang, Y.; Takizawa, K.; Kitai, R.
We present a new methodology which can determine magnetic helicity transport by the passage of helical magnetic field lines from the sub-photosphere and the shuffling motions of footpoints of preexisting coronal field lines separately. It is well known that only the velocity component, which is perpendicular to the magnetic field (υ B )…
Evolution in the Dust Lane Fraction of Edge-on L* V Spiral Galaxies Since z = 0.8
Dalcanton, J. J.; Koekemoer, A.; Böker, T. +5 more
The presence of a well-defined and narrow dust lane in an edge-on spiral galaxy is the observational signature of a thin and dense molecular disk, in which gravitational collapse has overcome turbulence. Using a sample of galaxies out to z ~ 1 extracted from the COSMOS survey, we identify the fraction of massive (L* V ) disks that displ…
Matching the Spectral Energy Distribution and P-mode Oscillation Frequencies of the Rapidly Rotating Delta Scuti Star α Ophiuchi with a Two-dimensional Rotating Stellar Model
Deupree, Robert G.; Castañeda, Diego; Peña, Fernando +1 more
Spectral energy distributions are computed using two-dimensional (2D) rotating stellar models and non-LTE plane-parallel model atmospheres. A rotating, 2D stellar model has been found that matches the observed ultraviolet and visible spectrum of α Oph. The SED match occurs for the interferometrically deduced surface shape and inclination, and is d…
The Swift Burst Alert Telescope Perspective on Non-thermal Emission in HIFLUGCS Galaxy Clusters
Sarazin, Craig L.; Okajima, Takashi; Wik, Daniel R. +5 more
The search for diffuse non-thermal, inverse Compton (IC) emission from galaxy clusters at hard X-ray energies has been underway for many years, with most detections being either of low significance or controversial. In this work, we investigate 14-195 keV spectra from the Swift Burst Alert Telescope (BAT) all-sky survey for evidence of non-thermal…