Search Publications
Ne X X-ray emission due to charge exchange in M82
Liu, L.; Cumbee, R. S.; Lyons, D. +4 more
Recent X-ray observations of star-forming galaxies such as M82 have shown the Ly β/Ly α line ratio of Ne X to be in excess of predictions for thermal electron impact excitation. Here, we demonstrate that the observed line ratio may be due to charge exchange and can be used to constrain the ion kinetic energy to be ≲ 500 eV/u. This is accomplished …
X-ray/UV variability and the origin of soft X-ray excess emission from II Zw 177
Dewangan, Gulab C.; Pal, Main; Misra, Ranjeev +1 more
We study X-ray and UV emission from the narrow-line Seyfert 1 galaxy II Zw 177 using a 137 ks long and another 13 ks short XMM-Newton observation performed in 2012 and 2001, respectively. Both observations show soft X-ray excess emission contributing 76.9 ± 4.9 per cent in 2012 and 58.8 ± 10.2 per cent in 2001 in the 0.3-2 keV band. We find that b…
Where are all of the nebulae ionized by supersoft X-ray sources?
Gilfanov, M.; Woods, T. E.
Accreting, steadily nuclear-burning white dwarfs are associated with so-called close-binary supersoft X-ray sources (SSSs), observed to have temperatures of a few × 105 K and luminosities on the order of 1038 erg s-1. These and other types of SSSs are expected to be capable of ionizing their surrounding circumstell…
Insights into the location and dynamics of the coolest X-ray emitting gas in clusters of galaxies
Zhang, Y. -Y.; Finoguenov, A.; de Plaa, J. +10 more
We extend our previous study of the cool gas responsible for the emission of O VII X-ray lines in the cores of clusters and groups of galaxies. This is the coolest X-ray emitting phase and connects the 10 000 K H α emitting gas to the million degree phase, providing a useful tool to understand cooling in these objects. We study the location of the…
The ATCA REXCESS Diffuse Emission Survey (ARDES) - I. Detection of a giant radio halo and a likely radio relic
Pratt, G. W.; Johnston-Hollitt, M.; Shakouri, S.
We present the results of the radio halo survey of 16 REXCESS southern clusters up to a redshift of 0.2 with the Australia Telescope Compact Array (ATCA) at 1.4 and 2.1 GHz. This cluster sample called the ATCA REXCESS Diffuse Emission Survey (ARDES) includes clusters in a wide range of X-ray luminosities and is morphologically unbiased. We find tw…
On the properties of the interstellar medium in extremely metal-poor blue compact dwarf galaxies. A VIMOS-IFU study of the cometary galaxy and Ly α absorber Tol 65
Demarco, R.; Humphrey, A.; Roche, N. +5 more
In this study, we present high-resolution VIsible Multi-Object Spectrograph integral field unit spectroscopy (VIMOS-IFU) of the extremely metal-poor H II/blue compact dwarf (BCD) galaxy Tol 65. The optical appearance of this galaxy shows clearly a cometary morphology with a bright main body and an extended and diffuse stellar tail. We focus on the…
Revisiting the role of the thermally pulsating asymptotic-giant-branch phase in high-redshift galaxies
Daddi, Emanuele; Maraston, Claudia; Renzini, Alvio +3 more
We study the debated contribution from thermally pulsing asymptotic-giant-branch (TP-AGB) stars in evolutionary population synthesis models. We investigate the spectral energy distributions (SEDs) of a sample of 51 spectroscopically confirmed, high-z (1.3 < zspec < 2.7), galaxies using three evolutionary population synthesis model…
Cosmic infrared background anisotropies as a window into primordial non-Gaussianity
Kunz, Martin; Tucci, Marco; Desjacques, Vincent
The angular power spectrum of the cosmic infrared background (CIB) is a sensitive probe of the local primordial bispectrum. CIB measurements are integrated over a large volume so that the scale-dependent bias from the primordial non-Gaussianity leaves a strong signal in the CIB power spectrum. Although Galactic dust dominates over the non-Gaussian…
Gaussianization for fast and accurate inference from cosmological data
Peiris, Hiranya V.; Joachimi, Benjamin; Schuhmann, Robert L.
We present a method to transform multivariate unimodal non-Gaussian posterior probability densities into approximately Gaussian ones via non-linear mappings, such as Box-Cox transformations and generalizations thereof. This permits an analytical reconstruction of the posterior from a point sample, like a Markov chain, and simplifies the subsequent…
Ionized gas kinematics within the inner kiloparsec of the Seyfert galaxy NGC 1365
Robinson, Andrew; Schnorr-Müller, Allan; Storchi-Bergmann, Thaisa +3 more
We observed the nuclear region of the galaxy NGC 1365 with the integral field unit of the Gemini Multi Object Spectrograph mounted on the GEMINI-South telescope. The field of view covers 13 × 6 arcsec2(1173 × 541 pc2) centred on the nucleus, at a spatial resolution of 52 pc. The spectral coverage extends from 5600 to 7000 Å, …