Search Publications
An Explanation of Remarkable Emission-line Profiles in Post-flare Coronal Rain
Judge, Philip G.; Donea, Alina; Lacatus, Daniela A.
We study broad redshifted emission in chromospheric and transition region lines that appears to correspond to a form of post-flare coronal rain. Profiles of Mg II, C II, and Si IV lines were obtained using IRIS before, during, and after the X2.1 flare of 2015 March 11 (SOL2015-03-11T16:22). We analyze the profiles of the five transitions of Mg II …
On the Absence of Non-thermal X-Ray Emission around Runaway O Stars
Toalá, J. A.; Oskinova, L. M.; Ignace, R.
Theoretical models predict that the compressed interstellar medium around runaway O stars can produce high-energy non-thermal diffuse emission, in particular, non-thermal X-ray and γ-ray emission. So far, detection of non-thermal X-ray emission was claimed for only one runaway star, AE Aur. We present a search for non-thermal diffuse X-ray emissio…
Dense Gas in the Outer Spiral Arm of M51
Gao, Yu; Koda, Jin; Gu, Qiusheng +2 more
There is a linear relation between the mass of dense gas traced by the HCN(1-0) luminosity and the star formation rate (SFR) traced by the far-infrared luminosity. Recent observations of galactic disks have shown some systematic variations. In order to explore the SFR-dense gas link at high resolution (∼4″, ∼150 pc) in the outer disk of an externa…
3D Polarized Imaging of Coronal Mass Ejections: Chirality of a CME
de Koning, C. A.; Elliott, H. A.; DeForest, C. E.
We report on a direct polarimetric determination of the chirality of a coronal mass ejection (CME), using the physics of Thomson scattering applied to synoptic polarized images from the Solar Terrestrial Relations Observatories/COR2 coronagraph. We confirmed the determination using in situ magnetic field measurements of the same CME with the ACE s…
An Ultraviolet Survey of Low-redshift Partial Lyman-limit Systems with the HST Cosmic Origins Spectrograph
Stevans, Matthew L.; Shull, J. Michael; Danforth, Charles W. +2 more
We present an ultraviolet spectroscopic survey of strong H I absorbers in the intergalactic medium, probing their evolution over the last 6-7 Gyr at redshifts 0.24 ≤ z ≤ 0.84. We measure column densities N H I (cm-2) from the pattern of Lyman-series absorption lines and flux decrement at the Lyman limit (LL) when available. …
Magnetic Flux Rope Shredding By a Hyperbolic Flux Tube: The Detrimental Effects of Magnetic Topology on Solar Eruptions
Vourlidas, Angelos; Stenborg, Guillermo; Chintzoglou, Georgios +3 more
We present the analysis of an unusual failed eruption captured in high cadence and in many wavelengths during the observing campaign in support of the Very high Angular resolution Ultraviolet Telescope (VAULT2.0) sounding rocket launch. The refurbished VAULT2.0 is a Lyα (λ 1216 Å) spectroheliograph launched on 2014 September 30. The campaign targe…
A Universal Correlation between Star Formation Activity and Molecular Gas Properties Across Environments
Nakagawa, Takao; Suzuki, Tomoko L.; Koyama, Yusei +10 more
We present the molecular gas mass fraction ({f}{{{H}}2}) and star formation efficiency (SFE) of local galaxies on the basis of our new CO(J=1-0) observations with the Nobeyama 45 m radio telescope, combined with the COLDGASS galaxy catalog, as a function of galaxy environment defined as the local number density of galaxies me…
NuSTAR Hard X-Ray Observations of the Energetic Millisecond Pulsars PSR B1821-24, PSR B1937+21, and PSR J0218+4232
Gotthelf, E. V.; Bogdanov, S.
We present Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray timing and spectroscopy of the three exceptionally energetic rotation-powered millisecond pulsars PSRs B1821-24, B1937+21, and J0218+4232. By correcting for the frequency and phase drifts of the NuSTAR onboard clock, we are able to recover the intrinsic hard X-ray pulse profiles …
Measure the Propagation of a Halo CME and Its Driven Shock with the Observations from a Single Perspective at Earth
Feng, Li; Lu, Lei; Inhester, Bernd +2 more
We present a detailed study of an Earth-directed coronal mass ejection (full-halo CME) event that happened on 2011 February 15, making use of white-light observations by three coronagraphs and radio observations by Wind/WAVES. We applied three different methods to reconstruct the propagation direction and traveling distance of the CME and its driv…
Multi-wavelength Spectral Analysis of Ellerman Bombs Observed by FISS and IRIS
Cao, Wenda; Ding, M. D.; Hong, Jie
Ellerman bombs (EBs) are a kind of solar activity that is suggested to occur in the lower solar atmosphere. Recent observations using the Interface Region Imaging Spectrograph (IRIS) show connections between EBs and IRIS bombs (IBs), which imply that EBs might be heated to a much higher temperature (8 × 104 K) than previous results. Her…