Search Publications
Hard X-Ray Emission from Sh 2-104: A NuSTAR Search for Gamma-Ray Counterparts
Harrison, F. A.; Stern, D.; Zhang, W. W. +11 more
We present NuSTAR hard X-ray observations of Sh 2-104, a compact H II region containing several young massive stellar clusters (YMSCs). We have detected distinct hard X-ray sources coincident with localized VERITAS TeV emission recently resolved from the giant gamma-ray complex MGRO J2019+37 in the Cygnus region. Fainter, diffuse X-rays coincident…
On the Bright Loop Top Emission in Post-eruption Arcades
Isobe, Hiroaki; Tripathi, Durgesh; Ghosh, Avyarthana +1 more
Observations of post-eruption arcades (PEAs) in X-rays and EUV reveal strong localized brightenings at the loop top regions. The origins of these brightenings and their dynamics are not well understood to date. Here, we study the dynamics of PEAs using one-dimensional hydrodynamic modeling, focusing on understanding the formation of localized brig…
Coeval Intermediate-mass Star Formation in N4W
Chen, Zhiwei; Kwon, Jungmi; Tamura, Motohide +3 more
Protostars are mostly found in star-forming regions, where the natal molecular gas still remains. At about 5\prime west of the molecular bubble N4, N4W is identified as a star-forming clump hosting three Class II (IRS 1-3), and one Class I (IRS 4) young stellar objects (YSOs), as well as a submillimeter source SMM1. The near-IR polariza…
What Is the Source of Quiet Sun Transition Region Emission?
De Pontieu, Bart; Schmit, D. J.
Dating back to the first observations of the on-disk corona, there has been a qualitative link between the photosphere’s magnetic network and enhanced transition-temperature plasma emission. These observations led to the development of a general model that describes emission structures through the partitioning of the atmospheric volume with differ…
Calibration of the Voyager Ultraviolet Spectrometers and the Composition of the Heliosphere Neutrals: Reassessment
Holberg, J. B.; Ben-Jaffel, Lotfi
The data harvest from the Voyagers’ (V 1 and V 2) Ultraviolet Spectrometers (UVS) covers encounters with the outer planets, measurements of the heliosphere sky-background, and stellar spectrophotometry. Because their period of operation overlaps with many ultraviolet missions, the calibration of V1 and V2 UVS with other spectrometers is invaluable…
On the Rotation of Sunspots and Their Magnetic Polarity
Wang, Haimin; Yang, Zhiliang; Wang, Shuo +2 more
The rotation of sunspots of 2 yr in two different solar cycles is studied with the data from the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory and the Michelson Doppler Imager instrument on board the Solar and Heliospheric Observataory. We choose the α sunspot groups and the relatively large and stable sunspots of comple…
Fermi-LAT Observations of Supernova Remnant G5.7-0.1, Believed to be Interacting with Molecular Clouds
Slane, Patrick; Castro, Daniel; Gelfand, Joseph +1 more
This work reports on the detection of γ-ray emission coincident with the supernova remnant (SNR) G5.7-0.1 using data collected by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. The SNR is believed to be interacting with molecular clouds, based on 1720 MHz hydroxyl (OH) maser emission observations in its direction. This inte…
Dense Molecular Cores Being Externally Heated
Kim, Gwanjeong; Kim, Mi-Ryang; Lee, Chang Won +2 more
We present results of our study of eight dense cores, previously classified as starless, using infrared (3-160 µm) imaging observations with the AKARI telescope and molecular line (HCN and N2H+) mapping observations with the KVN telescope. Combining our results with the archival IR to millimeter continuum data, we exami…
An Imaging Study of a Complex Solar Coronal Radio Eruption
Feng, S. W.; Chen, Y.; Song, H. Q. +2 more
Solar coronal radio bursts are enhanced radio emission excited by energetic electrons accelerated during solar eruptions. Studying these bursts is important for investigating the origin and physical mechanism of energetic particles and further diagnosing coronal parameters. Earlier studies suffered from a lack of simultaneous high-quality imaging …
Far-UV Emission Properties of FR1 Radio Galaxies
Danforth, Charles W.; France, Kevin; Stocke, John T. +2 more
The power mechanism and accretion geometry for low-power FR 1 radio galaxies are poorly understood in comparison to those for Seyfert galaxies and QSOs. In this paper, we use the diagnostic power of the Lyα recombination line observed using the Cosmic Origins Spectrograph (COS) aboard the Hubble Space Telescope (HST) to investigate the accretion f…