Search Publications
Probing cool giants in unresolved galaxies using fluctuation eigenspectra: A demonstration using high-resolution MUSE observations of NGC 5128
Smith, Russell J.
I describe and demonstrate a new approach to using spectroscopic data to exploit Poisson sampling fluctuations in unresolved stellar populations. The method is introduced using spectra predicted for independent samples of stars from a 10 Gyr population using a simple stochastic spectral synthesis model. A principal components analysis shows that &…
Impact of dust loading on ozone, winds and heating rates in the atmosphere of mars: Seasonal variability, climatology and SPICAM observations
Haider, S. A.; Masoom, J.; Siddhi, Y. S. +2 more
We have used SPICAM-UV nadir observations for four Martian Years (MY27-MY30) to study the seasonal variability of column abundances of ozone and dust opacity at low latitudes (10°-30°), mid-latitudes (30°-50°) and high latitudes (50°-70°) in both hemispheres. The observed column abundances of ozone are compared with the Mars Climate Database (MCD,…
Simplified Automatic Atmospheric Correction for THEMIS Infrared Data
Edwards, Christopher S.; Rogers, A. Deanne; Ye, Cheng +1 more
Thermal infrared spectral data from the Thermal Emission Imaging System (THEMIS) on Mars Odyssey can provide diagnostic information to characterize Martian surface compositions. Accurately isolating the atmospheric contribution from the thermal radiance of THEMIS data is essential for surface mineralogy analysis. In this work, we present improved …
The MAVERIC Survey: The first radio and X-ray limits on the detached black holes in NGC 3201
Kamann, Sebastian; Dreizler, Stefan; Strader, Jay +11 more
The Galactic globular cluster (GC) NGC 3201 is the first Galactic GC observed to host dynamically confirmed stellar-mass black holes (BHs), containing two confirmed and one candidate BH. This result indicates that GCs can retain BHs, which has important implications for GC evolution. NGC 3201 has been observed as part of the MAVERIC survey of Gala…
A Suzaku sample of unabsorbed narrow-line and broad-line Seyfert 1 galaxies - II. Iron emission and absorption
Gallo, L. C.; Waddell, S. G. H.
A sample of 22 narrow-line type 1 Seyfert (NLS1) and 47 broad-line type 1 Seyfert (BLS1) galaxies observed with Suzaku is used to examine the Fe K-band properties of each group. Three different models are used to examine the presence of: narrow neutral Fe K α line at $6.4{\rm \, keV}$ and ionized Fe XXV and Fe XXVI emission lines (model A); a broa…
First investigation of the diamagnetic cavity boundary layer with a 1D3V PIC simulation
Gunell, H.; Nilsson, H.; Hamrin, M. +3 more
Context. Amongst the different features and boundaries encountered around comets, one remains of particular interest to the plasma community: the diamagnetic cavity. Crossed for the first time at 1P/Halley during the Giotto flyby in 1986 and later met more than 700 times by the ESA Rosetta spacecraft around Comet 67P/Churyumov-Gerasimenko, this re…
Detailed evolutionary models for twins in sight of new spectral data: AN Cam, RS Ari, and V455 Aur
Bakış, Volkan; Yücel, Gökhan
We present the evolutionary scenarios for three eclipsing twin (q(M2/M1) ~1) binary systems using their combined spectroscopic and photometric data. Using accurate TESS photometric data, RV measurements, and spectroscopic data enabled us to calculate fundamental parameters, such as mass and radius, better than 2 per cent. The…
Early Noachian terrains: Vestiges of the early evolution of Mars
Dohm, James M.; Buczkowski, Debra; Anderson, Robert C. +1 more
NASA's main scientific reason for exploring Mars is to determine the early evolution and the possibility of life on the red planet. Scientists have adopted an approach for identifying habitable environments on Mars that could be conducive to the early development and preservation of life (e.g., robotically exploring hydrothermal and lake deposits …
Expanding shells around young clusters - S 171/Be 59
Persson, C. M.; Gahm, G. F.; Wilhelm, M. J. C. +2 more
Context. Some HII regions that surround young stellar clusters are bordered by molecular shells that appear to expand at a rate inconsistent with our current model simulations. In this study we focus on the dynamics of Sharpless 171 (including NGC 7822), which surrounds the cluster Berkeley 59.
Aims: We aim to compare the velocity pattern ove…
Gaia GraL: Gaia DR2 Gravitational Lens Systems. VII. XMM-Newton Observations of Lensed Quasars
Djorgovski, S. G.; Connor, Thomas; Walton, Dominic J. +23 more
We present XMM-Newton X-ray observations of nine confirmed lensed quasars at 1 ≲ z ≲ 3 identified by the Gaia Gravitational Lens program. Eight systems are strongly detected, with 0.3-8.0 keV fluxes F 0.3-8.0 ≳ 5 ×10-14 erg cm-2 s-1. Modeling the X-ray spectra with an absorbed power law, we derive power-…