Search Publications
Observations and Modeling of the Onset of Fast Reconnection in the Solar Transition Region
Peter, H.; De Pontieu, Bart; Huang, Y. -M. +2 more
Magnetic reconnection is a fundamental plasma process that plays a critical role not only in energy release in the solar atmosphere, but also in fusion, astrophysics, and other space plasma environments. One of the challenges in explaining solar observations in which reconnection is thought to play a critical role is to account for the transition …
HST Survey of the Orion Nebula Cluster in the H2O 1.4 µm Absorption Band. I. A Census of Substellar and Planetary-mass Objects
Da Rio, Nicola; Gennaro, Mario; Pacifici, Camilla +15 more
In order to obtain a complete census of the stellar and substellar population, down to a few ${M}_{\mathrm{Jup}}$ in the ∼1 Myr old Orion Nebula Cluster, we used the infrared channel of the Wide Field Camera 3 of the Hubble Space Telescope with the F139M and F130N filters. These bandpasses correspond to the 1.4 µm H2O absorption f…
REQUIEM-2D Methodology: Spatially Resolved Stellar Populations of Massive Lensed Quiescent Galaxies from Hubble Space Telescope 2D Grism Spectroscopy
Mahler, Guillaume; Bezanson, Rachel; Brammer, Gabriel +13 more
We present a novel Bayesian methodology to jointly model photometry and deep Hubble Space Telescope 2D grism spectroscopy of high-redshift galaxies. Our requiem2d code measures both unresolved and resolved stellar populations, ages, and star formation histories (SFHs) for the ongoing REsolving QUIEscent Magnified (REQUIEM) Galaxies Survey, which t…
Interplanetary Protons versus Interacting Protons in the 2017 September 10 Solar Eruptive Event
Jin, Meng; Heber, Bernd; Vainio, Rami +11 more
We analyze the relativistic proton emission from the Sun during the eruptive event on 2017 September 10, which caused a ground-level enhancement (GLE 72) registered by the worldwide network of neutron monitors. Using the neutron monitor data and interplanetary transport modeling both along and across interplanetary magnetic field (IMF) lines, we d…
Hard X-Ray Emission from an Activated Flux Rope and Subsequent Evolution of an Eruptive Long-duration Solar Flare
Joshi, Bhuwan; Veronig, Astrid M.; Yurchyshyn, V. +2 more
In this paper, we present a comprehensive study of the evolutionary phases of a major M6.6 long duration event with special emphasize on its pre-flare phase. The event occurred in NOAA 12371 on 2015 June 22. A remarkable aspect of the event was an active pre-flare phase lasting for about an hour during which a hot EUV coronal channel was in the bu…
VERITAS Discovery of VHE Emission from the Radio Galaxy 3C 264: A Multiwavelength Study
Fortin, P.; Archer, A.; Benbow, W. +67 more
The radio source 3C 264, hosted by the giant elliptical galaxy NGC 3862, was observed with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) between 2017 February and 2019 May. These deep observations resulted in the discovery of very high energy (VHE; E > 100 GeV) γ-ray emission from this active galaxy. An analysis of ∼57 h…
Multiwavelength Polarimetry of the Filamentary Cloud IC 5146. II. Magnetic Field Structures
Wang, Jia-Wei; Lai, Shih-Ping; Eswaraiah, Chakali +4 more
The IC 5146 cloud is a nearby star-forming region in Cygnus, consisting of molecular gas filaments in a variety of evolutionary stages. We used optical and near-infrared polarization data toward the IC 5146 cloud, reported in the first paper of this series, to reveal the magnetic fields in this cloud. Using the newly released Gaia data, we found t…
A Broadband X-Ray Study of a Sample of AGNs with [O III] Measured Inclinations
Ajello, M.; Marchesi, S.; Baloković, M. +2 more
In modeling the X-ray spectra of active galactic nuclei (AGNs), the inclination angle is a parameter that can play an important role in analyzing the X-ray spectra of AGNs, but it has never been studied in detail. We present a broadband X-ray spectral analysis of the joint Nuclear Spectroscopic Telescope Array-XMM-Newton observations of 13 sources…
The Warm-Hot, Extended, Massive Circumgalactic Medium of NGC 3221: An XMM-Newton Discovery
Mathur, Smita; Gupta, Anjali; Das, Sanskriti
Using Suzaku data, we had found a 3.4σ evidence for the X-ray emitting warm-hot circumgalactic medium (CGM) in the L⋆ galaxy NGC 3221. Here we present XMM-Newton data and outline an efficient, rigorous, and well-defined method to extract the faint CGM signal. We confirm the CGM detection at 4σ significance within 30-200 kpc of the galax…
Formation of Post-CME Blobs Observed by LASCO-C2 and K-Cor on 2017 September 10
Lee, Kyoung-Sun; Jang, Soojeong; Cho, Kyung-Suk +6 more
Understanding the formation of post-CME blobs, we investigate 2 blobs in the outer corona observed by LASCO-C2 and 34 blobs in the inner corona by K-Cor on 2017 September 10 from 17:11 to 18:58 UT. By visual inspection of the structure of a post-CME current sheet (CS) and its associated blobs, we find that the CS is well identified in the K-Cor an…