Search Publications
Solar Flare Termination Shock and Synthetic Emission Line Profiles of the Fe xxi 1354.08 Å Line
Li, Gang; Raymond, John; Guo, Lijia +1 more
Solar flares are among the most energetic phenomena that occur in the solar system. In the standard solar flare model, a fast mode shock, often referred to as the flare termination shock (TS), can exist above the loop-top source of hard X-ray emissions. The existence of the TS has been recently related to spectral hardening of a flare’s hard X-ray…
Little Blue Dots in the Hubble Space Telescope Frontier Fields: Precursors to Globular Clusters?
Elmegreen, Bruce G.; Elmegreen, Debra Meloy
Galaxies with stellar masses < {10}7.4 {M}⊙ and specific star formation rates {sSFR}> {10}-7.4 yr-1 were examined on images of the Hubble Space Telescope Frontier Field Parallels for Abell 2744 and MACS J0416.1-02403. They appear as unresolved “Little Blue Dots” (LBDs). They are less massive and h…
NuSTAR and XMM-Newton Observations of the 2015 Outburst Decay of GX 339-4
Stiele, H.; Kong, A. K. H.
The extent of the accretion disk in the low/hard state of stellar mass black hole X-ray binaries remains an open question. There is some evidence suggesting that the inner accretion disk is truncated and replaced by a hot flow, while the detection of relativistic broadened iron emission lines seems to require an accretion disk extending fully to t…
Detection of two intervening Ne viii absorbers probing warm gas at z ∼ 0.6
Savage, Blair D.; Wakker, Bart P.; Muzahid, Sowgat +3 more
We report on the detection of two Ne viii absorbers, at z = 0.619 07 and 0.570 52 in the Hubble Space Telescope/Cosmic Origins Spectrograph spectrum of background quasars SDSS J080908.13 + 461925.6 and SBS 1122 + 594, respectively. The Ne viii 770 line is at ∼3σ significance. In both instances, the Ne viii is found to be tracing gas with T ≳ 10
The dependence of magnetospheric plasma mass loading on geomagnetic activity using Cluster
Dandouras, I.; Sandhu, J. K.; Yeoman, T. K. +2 more
Understanding changes in the magnetospheric mass density during disturbed geomagnetic conditions provides valuable insight into the dynamics and structure of the environment. The mass density plays a significant role in a variety of magnetospheric processes, such as wave propagation, magnetic reconnection rates, and radiation belt dynamics. In thi…
The Abundance of C2H4 in the Circumstellar Envelope of IRC+10216
Hinkle, K. H.; Cernicharo, J.; Fonfría, J. P. +3 more
High spectral resolution mid-IR observations of ethylene ({{{C}}}2{{{H}}}4) toward the AGB star IRC+10216 were obtained using the Texas Echelon Cross Echelle Spectrograph (TEXES) at the NASA Infrared Telescope Facility (IRTF). 80 ro-vibrational lines from the 10.5 µm vibrational mode {ν }7 with J ≲ 30 were de…
Attenuation Modified by DIG and Dust as Seen in M31
Schinnerer, Eva; Blanc, Guillermo A.; Kreckel, Kathryn +5 more
The spatial distribution of dust in galaxies affects the global attenuation, and hence inferred properties, of galaxies. We trace the spatial distribution of dust in five approximately kiloparsec fields of M31 by comparing optical attenuation with the total dust mass distribution. We measure the attenuation from the Balmer decrement using Integral…
Comparing Submillimeter Polarized Emission with Near-infrared Polarization of Background Stars for the Vela C Molecular Cloud
Ward-Thompson, Derek; Fissel, Laura M.; Nakamura, Fumitaka +27 more
We present a large-scale combination of near-infrared (near-IR) interstellar polarization data from background starlight with polarized emission data at submillimeter wavelengths for the Vela C molecular cloud. The near-IR data consist of more than 6700 detections probing a range of visual extinctions between 2 and 20 {mag} in and around the cloud…
Nature of the Diffuse Source and Its Central Point-like Source in SNR 0509-67.5
Pan, Kuo-Chuan; Ricker, Paul M.; Weisz, Daniel R. +7 more
We examine a diffuse emission region near the center of SNR 0509-67.5 to determine its nature. Within this diffuse region we observe a point-like source that is bright in the near-IR, but is not visible in the B and V bands. We consider an emission line observed at 6766 Å and the possibilities that it is Lyα, Hα, and [O II] λ3727. We examine the s…
Similarities and uniqueness of Ly α emitters among star-forming galaxies at z = 2.5
Shibuya, Takatoshi; Suzuki, Tomoko L.; Koyama, Yusei +8 more
We conducted a deep narrow-band imaging survey with the Subaru Prime Focus Camera on the Subaru Telescope and constructed a sample of Lyα emitters (LAEs) at z = 2.53 in the UDS-CANDELS field, where a sample of Hα emitters (HAEs) at the same redshift is already obtained from our previous narrow-band observation at near-infrared. The deep narrow-ban…