Search Publications
The Emerging Planetary Nebula CRL 618 and its Unsettled Central Star(s)
Velázquez, P. F.; Balick, B.; Kwitter, K. B. +2 more
We report deep long-slit emission-line spectra, the line flux ratios, and Doppler profile shapes of various bright optical lines. The low-ionization lines (primarily [N I], [O I], [S II], and [N II]) originate in shocked knots, as reported by many previous observers. Dust-scattered lines of higher ionization are seen throughout the lobes but do no…
Verification of the Helioseismology Travel-time Measurement Technique and the Inversion Procedure for Sound Speed Using Artificial Data
Kosovichev, A. G.; Parchevsky, K. V.; Zhao, J. +1 more
We performed three-dimensional numerical simulations of the solar surface acoustic wave field for the quiet Sun and for three models with different localized sound-speed perturbations in the interior with deep, shallow, and two-layer structures. We used the simulated data generated by two solar acoustics codes that employ the same standard solar m…
The Dynamic Character of the Polar Solar Wind
Jackson, B. V.; Buffington, A.; Hick, P. P. +1 more
The Solar and Heliospheric Observatory (SOHO) Large Angle and Spectrometric Coronagraph C2 and Solar Terrestrial Relations Observatory (STEREO) COR2A coronagraph images, when analyzed using correlation tracking techniques, show a surprising result in places ordinarily thought of as "quiet" solar wind above the poles in coronal hole regions. Instea…
Erratum: "Joint Analysis of Cluster Observations. II. Chandra/XMM-Newton X-Ray and Weak Lensing Scaling Relations for a Sample of 50 Rich Clusters of Galaxies" (2013, ApJ, 767, 116)
Hoekstra, Henk; Babul, Arif; Mahdavi, Andisheh +3 more
Physical Nature of the [S II]-bright Shell Nebulae N70 and N185
Gruendl, R. A.; Chu, You-Hua; Chen, Yang +3 more
N70 and N185 are two large (>=100 pc in diameter) shell nebulae in the Large Magellanic Cloud (LMC). Their high [S II]/Hα ratios rival those of supernova remnants (SNRs), but they are not confirmed as SNRs. To study their physical nature, we have obtained XMM-Newton X-ray observations and high-dispersion long-slit echelle spectroscopic observat…
Modeling Active Region Transient Brightenings Observed with X-Ray Telescope as Multi-stranded Loops
McKenzie, David E.; Donachie, Martin; Kobelski, Adam R.
Strong evidence exists that coronal loops as observed in extreme ultraviolet and soft X-rays may not be monolithic isotropic structures, but can often be more accurately modeled as bundles of independent strands. Modeling the observed active region transient brightenings (ARTBs) within this framework allows for the exploration of the energetic ram…
Fe-rich Ejecta in the Supernova Remnant G352.7-0.1 with Suzaku
Sezer, A.; Gök, F.
In this work, we present results from a ~201.6 ks observation of G352.7-0.1 using the X-ray Imaging Spectrometer on board Suzaku X-ray Observatory. The X-ray emission from the remnant is well described by two-temperature thermal models of non-equilibrium ionization with variable abundances with a column density of N H ~ 3.3 × 1022<…
Early-type Galaxies at Intermediate Redshift Observed with Hubble Space Telescope WFC3: Perspectives on Recent Star Formation
Hathi, Nimish P.; Rutkowski, Michael J.; Windhorst, Rogier A. +7 more
We present an analysis of the stellar populations of 102 visually selected early-type galaxies (ETGs) with spectroscopic redshifts (0.35 lsim z lsim 1.5) from observations in the Early Release Science program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). We fit one- and two-component synthetic stellar models to the ETGs …
Full Particle Electromagnetic Simulations of Entropy Generation across a Collisionless Shock
Wang, Rui; Yang, Zhongwei; Liu, Ying D. +5 more
Experimental data from Cluster have shown that entropy density can be generated across Earth's bow shock. These new observations are a starting point for a more sophisticated analysis that includes computer modeling of a collisionless shock using observed shock parameters as input. In this Letter, we present the first comparison between observatio…
Tracing Recent Star Formation of Red Early-type Galaxies out to z ~ 1
Im, Myungshin; Lee, Jong Chul; Hwang, Ho Seong +3 more
We study the mid-infrared (IR) excess emission of early-type galaxies (ETGs) on the red sequence at z < 1 using a spectroscopic sample of galaxies in the fields of Great Observatories Origins Deep Survey (GOODS). In the mass-limited sample of 1025 galaxies with M star > 1010.5 M ⊙ and 0.4 < z < 1.05, we…