Search Publications
Evolutionary stages and triggering process of a complex eruptive flare with circular and parallel ribbons
Joshi, Bhuwan; Joshi, Navin Chandra; Mitra, Prabir K.
We report multiwavelength study of a complex M-class solar eruptive flare that consists of three different sets of flare ribbons, viz. circular, parallel, and remote ribbons. Magnetic field modelling of source active region NOAA 12242 exhibits the presence of 3D null-point magnetic topology that encompasses an inner bipolar region. The event initi…
Energetic Proton Propagation and Acceleration Simulated for the Bastille Day Event of 2000 July 14
Downs, Cooper; Riley, Pete; Schwadron, Nathan A. +9 more
This work presents results from simulations of the 2000 July 14 ("Bastille Day") solar proton event. We used the Energetic Particle Radiation Environment Model (EPREM) and the CORona-HELiosphere (CORHEL) software suite within the SPE Threat Assessment Tool (STAT) framework to model proton acceleration to GeV energies due to the passage of a CME th…
Potential origin of the state-dependent high-energy tail in the black hole microquasar Cygnus X-1 as seen with INTEGRAL
Rodriguez, J.; Siegert, T.; Wilms, J. +8 more
Context. 0.1-10 MeV observations of the black hole microquasar Cygnus X-1 have shown the presence of a spectral feature in the form of a power law in addition to the standard black body (0.1-10 keV) and Comptonization (10-200 keV) components observed by INTEGRAL in several black-hole X-ray binaries. This so-called "high-energy tail" was recently s…
Total mass density slopes of early-type galaxies using Jeans dynamical modelling at redshifts 0.29 < z < 0.55
Emsellem, Eric; Jørgensen, Inger; McDermid, Richard M. +3 more
The change of the total mass density slope, γ, of early-type galaxies through cosmic time is a probe of evolutionary pathways. Hydrodynamical cosmological simulations show that at high redshifts density profiles of early-type galaxies were on average steep (γ ~ -3). As redshift approaches zero, gas-poor mergers progressively cause the total mass d…
Revisiting the gas kinematics in SSA22 Lyman-α Blob 1 with radiative transfer modelling in a multiphase, clumpy medium
Steidel, Charles C.; Gronke, Max; Li, Zhihui +1 more
We present new observations of Lyman-α (Lyα) Blob 1 (LAB1) in the SSA22 protocluster region (z = 3.09) using the Keck Cosmic Web Imager and Keck Multi-object Spectrometer for Infrared Exploration. We have created a narrow-band Lyα image and identified several prominent features. By comparing the spatial distributions and intensities of Lyα and Hβ,…
J-PLUS: Systematic impact of metallicity on photometric calibration with the stellar locus
Hernández-Monteagudo, C.; Hernán-Caballero, A.; Tremblay, P. -E. +19 more
Aims: We present the photometric calibration of the twelve optical passbands for the Javalambre Photometric Local Universe Survey (J-PLUS) second data release (DR2), comprising 1088 pointings of two square degrees, and study the systematic impact of metallicity on the stellar locus technique.
Methods: The [Fe/H] metallicity from the Larg…
Spectroscopic Confirmation of the Sixth Globular Cluster in the Fornax Dwarf Spheroidal Galaxy
Caldwell, Nelson; Mateo, Mario; Bailey, John I., III +5 more
The Fornax dwarf spheroidal galaxy has an anomalous number of globular clusters, five, for its stellar mass. There is a longstanding debate about a potential sixth globular cluster (Fornax 6) that has recently been "rediscovered" in DECam imaging. We present new Magellan/M2FS spectroscopy of the Fornax 6 cluster and Fornax dSph. Combined with lite…
Extragalactic Magnetism with SOFIA (Legacy Program) - II: A Magnetically Driven Flow in the Starburst Ring of NGC 1097
Beckman, John E.; Hughes, Annie; Dale, Daniel +9 more
Galactic bars are frequent in disk galaxies and they may support the transfer of matter toward the central engine of active nuclei. The barred galaxy NGC 1097 has magnetic forces controlling the gas flow at several kpc scales, which suggest that magnetic fields (B-fields) are dynamically important along the bar and nuclear ring. However, the effec…
Stratigraphic Relationships in Jezero Crater, Mars: Constraints on the Timing of Fluvial-Lacustrine Activity From Orbital Observations
Hauber, E.; Gupta, S.; Quantin-Nataf, C. +15 more
On February 18, 2021 NASA's Perseverance rover landed in Jezero crater, located at the northwestern edge of the Isidis basin on Mars. The uppermost surface of the present-day crater floor is dominated by a distinct geologic assemblage previously referred to as the dark-toned floor. It consists of a smooth, dark-toned unit overlying and variably co…
Towards a more complete sample of binary central stars of planetary nebulae with Gaia
Rejkuba, M.; Walton, N. A.; Chornay, N. +3 more
Context. Many if not most planetary nebulae (PNe) are now thought to be the outcome of binary evolutionary scenarios. However, only a few percent of the PNe in the Milky Way are known to host binary systems. The high-precision repeated observing and long time baseline of Gaia make it well suited for detecting new close binaries through photometric…