Search Publications
Detailed Investigations of the Dimmest Bursts from Two Magnetars, SGR J0501+4516 and SGR J1550-5418
Kouveliotou, Chryssa; Göǧüş, Ersin; Lin, Lin +1 more
We applied the Bayesian blocks representation technique to search for the dimmest bursts from two magnetars: we identified 320 events from SGR J0501+4516 using a deep XMM-Newton observation and 404 bursts from SGR J1550-5418 using two Swift/X-Ray Telescope pointings. The fluence level of our sample for both sources is about one to two orders of ma…
The Structure of Massive Quiescent Galaxies at Z ~ 3 in the CANDELS-COSMOS Field
Fang, Guanwen; Kong, Xu; Lin, Lin +5 more
In this Letter, we use a two-color (J - L) versus (V - J) selection criterion to search massive quiescent galaxy (QG) candidates at 2.5 <= z <= 4.0 in the CANDELS-COSMOS field. We construct an H F160W-selected catalog and complement it with public auxiliary data. We finally obtain 19 passive VJL-selected (hereafter pVJL) galaxies …
Probing the Shallow Convection Zone: Rising Motion of Subsurface Magnetic Fields in the Solar Active Region
Toriumi, Shin; Yokoyama, Takaaki; Sekii, Takashi +1 more
In this Letter, we present a seismological detection of a rising motion of magnetic flux in the shallow convection zone of the Sun, and show estimates of the emerging speed and its decelerating nature. In order to evaluate the speed of subsurface flux that creates an active region, we apply six Fourier filters to the Doppler data of NOAA AR 10488,…
Deeper by the Dozen: Understanding the Cross-field Temperature Distributions of Coronal Loops
Schmelz, J. T.; Pathak, S.; Jenkins, B. S. +1 more
Spectroscopic analysis of coronal loops has revealed a variety of cross-field temperature distributions. Some loops appear to be isothermal while others require multithermal plasma. The EUV Imaging Spectrometer on Hinode has the spatial resolution and temperature coverage required for differential emission measure (DEM) analysis of coronal loops. …
On the Road to More Realistic Galaxy Cluster Simulations: The Effects of Radiative Cooling and Thermal Feedback Prescriptions on the Observational Properties of Simulated Galaxy Clusters
O'Shea, Brian W.; Burns, Jack O.; Smith, Britton D. +3 more
Flux-limited X-ray surveys of galaxy clusters show that clusters come in two roughly equally proportioned varieties: "cool core" clusters (CCs) and non-"cool core" clusters (NCCs). In previous work, we have demonstrated using cosmological N-body + Eulerian hydrodynamic simulations that NCCs are often consistent with early major merger events that …
Real or Interloper? The Redshift Likelihoods of z > 8 Galaxies in the HUDF12
Pirzkal, Nor; Coe, Dan; Ryan, Russell +4 more
In the absence of spectra, the technique of fitting model galaxy template spectra to observed photometric fluxes has become the workhorse method for determining the redshifts and other properties for high-z galaxy candidates. In this paper, we present an analysis of the most recent and possibly most distant galaxies (z ~ 8-12) discovered in the Hu…
Grain Destruction in a Supernova Remnant Shock Wave
Blair, William P.; Raymond, John C.; Ghavamian, Parviz +4 more
Dust grains are sputtered away in the hot gas behind shock fronts in supernova remnants (SNRs), gradually enriching the gas phase with refractory elements. We have measured emission in C IV λ1550 from C atoms sputtered from dust in the gas behind a non-radiative shock wave in the northern Cygnus Loop. Overall, the intensity observed behind the sho…
Probing Dynamics of Electron Acceleration with Radio and X-Ray Spectroscopy, Imaging, and Timing in the 2002 April 11 Solar Flare
Kontar, Eduard P.; Fleishman, Gregory D.; Nita, Gelu M. +1 more
Based on detailed analysis of radio and X-ray observations of a flare on 2002 April 11 augmented by realistic three-dimensional modeling, we have identified a radio emission component produced directly at the flare acceleration region. This acceleration region radio component has distinctly different (1) spectrum, (2) light curves, (3) spatial loc…
Observations of the High-mass X-Ray Binary A 0535+26 in Quiescence
Fürst, Felix; Pottschmidt, Katja; Wilms, Jörn +7 more
We have analyzed three observations of the high-mass X-ray binary A 0535+26 performed by the Rossi X-Ray Timing Explorer (RXTE) three, five, and six months after the last outburst in 2011 February. We detect pulsations only in the second observation. The 3-20 keV spectra can be fit equally well with either an absorbed power law or absorbed thermal…
Discovery of Nine Intermediate-redshift Compact Quiescent Galaxies in the Sloan Digital Sky Survey
Hwang, Ho Seong; Geller, Margaret J.; Damjanov, Ivana +1 more
We identify nine galaxies with dynamical masses of M dyn >~ 1010 M ⊙ as photometric point sources, but with redshifts between z = 0.2 and z = 0.6, in the Sloan Digital Sky Survey (SDSS) spectro-photometric database. All nine galaxies have archival Hubble Space Telescope images. Surface brightness profile fitting…