Search Publications
Conditions for galaxy quenching at 0.5 < z < 2.5 from CANDELS: compact cores and environment
Gu, Qiu-Sheng; Gu, Yi-Zhou; Ge, Xue +2 more
We investigate two classes of conditions for galaxy quenching at 0.5 < z < 2.5 based on the structural scaling relations of galaxies in the five Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) fields: the formation of a compact core and the environment. We confirm that in the entire redshift range, massive quiescent …
Some thoughts on emission-line spectroscopy
Judge, Philip G.
The interpretation of emission lines formed in large astrophysical plasmas such as the solar atmosphere faces many challenges. Relatively simple line-ratio estimates of physical parameters, while appealing, are heavily laden with assumptions. In practical cases, some critical assumptions are neither defensible from first principles, nor testable b…
On the origin of X-ray oxygen emission lines in obscured AGN
Bianchi, S.; Guainazzi, M.; García, F. +4 more
We present the Catalogue of High Resolution Spectra of Obscured Sources (CHRESOS) from the XMM-Newton Science Archive. It comprises the emission-line luminosities of H- and He-like transitions from C to Si, and the Fe 3C and Fe 3G L-shell ones. Here, we concentrate on the soft X-ray O VII (f) and O VIII Lyα emission lines to shed light on to the p…
HD 165054: An Astrometric Calibration Field for High-contrast Imagers in Baade's Window
Duchêne, Gaspard; Esposito, Thomas M.; Hom, Justin +51 more
We present a study of the HD 165054 astrometric calibration field that has been periodically observed with the Gemini Planet Imager (GPI). HD 165054 is a bright star within Baade's Window, a region of the galactic plane with relatively low extinction from interstellar dust. HD 165054 was selected as a calibrator target due to the high number densi…
Catalog of Solar Failed Eruptions and Other Dynamic Features Registered by SDO/AIA
Mrozek, Tomasz; Kołomański, Sylwester; Stęślicki, Marek +1 more
In this paper we present our attempt to constrain the first catalog of solar failed eruptions. We used our automatic algorithm that is able to search for dynamic features in the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) database. We ran the algorithm on the entire SDO/AIA 171 Å data set. For the time interval from 2010 Ma…
A NICER View of Spectral and Profile Evolution for Three X-Ray-emitting Millisecond Pulsars
Enoto, Teruaki; Bogdanov, Slavko; Ray, Paul S. +17 more
We present two years of Neutron star Interior Composition Explorer (NICER) X-ray observations of three energetic rotation-powered millisecond pulsars (MSPs): PSRs B1937+21, B1821-24, and J0218+4232. We fit Gaussians and Lorentzians to the pulse profiles for different energy sub-bands of the soft X-ray regime to measure the energy dependence of pul…
RESIK and RHESSI observations of the 20 September 2002 flare
Siarkowski, M.; Falewicz, R.; Kepa, A. +1 more
Context. Soft X-ray spectra (3.33 Å-6.15 Å) from the RESIK instrument on CORONAS-F constitute a unique database for the study of the physical conditions of solar flare plasmas, enabling the calculation of differential emission measures. The two RESIK channels for the shortest wavelengths overlap with the lower end of the Ramaty High Energy Solar S…
Opening pupils' eyes to the Sun
Baker, Deborah; Matthews, Sarah; Dunn, William +7 more
Ryan French and colleagues discuss their Hinode/EIS outreach work and the resulting resources available for A-level classes
Magnetic Rayleigh-Taylor instability at a contact discontinuity with an oblique magnetic field
Erdélyi, R.; Ballai, I.; Vickers, E.
Aims: We investigate the nature of the magnetic Rayleigh-Taylor instability at a density interface that is permeated by an oblique homogeneous magnetic field in an incompressible limit.
Methods: Using the system of linearised ideal incompressible magnetohydrodynamics equations, we derive the dispersion relation for perturbations of the c…
High-Spatiotemporal Resolution Observations of Jupiter Lightning-Induced Radio Pulses Associated With Sferics and Thunderstorms
Wong, Michael H.; Bolton, Scott J.; Levin, Steven M. +6 more
Jupiter lightning discharges produce various kinds of phenomena including radio wave pulses at different frequencies. On 6 April 2019, the Juno Waves instrument captured an extraordinary series of radio pulses at frequencies below 150 kHz on timescales of submilliseconds. Quasi-simultaneous multi-instrument data show that the locations of their ma…